diff -Nur linux-3.18.12.orig/arch/alpha/mm/fault.c linux-3.18.12/arch/alpha/mm/fault.c
--- linux-3.18.12.orig/arch/alpha/mm/fault.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/alpha/mm/fault.c	2015-04-26 13:32:22.351684003 -0500
@@ -107,7 +107,7 @@
 
 	/* If we're in an interrupt context, or have no user context,
 	   we must not take the fault.  */
-	if (!mm || in_atomic())
+	if (!mm || pagefault_disabled())
 		goto no_context;
 
 #ifdef CONFIG_ALPHA_LARGE_VMALLOC
diff -Nur linux-3.18.12.orig/arch/arm/include/asm/cmpxchg.h linux-3.18.12/arch/arm/include/asm/cmpxchg.h
--- linux-3.18.12.orig/arch/arm/include/asm/cmpxchg.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/arm/include/asm/cmpxchg.h	2015-04-26 13:32:22.351684003 -0500
@@ -129,6 +129,8 @@
 
 #else	/* min ARCH >= ARMv6 */
 
+#define __HAVE_ARCH_CMPXCHG 1
+
 extern void __bad_cmpxchg(volatile void *ptr, int size);
 
 /*
diff -Nur linux-3.18.12.orig/arch/arm/include/asm/futex.h linux-3.18.12/arch/arm/include/asm/futex.h
--- linux-3.18.12.orig/arch/arm/include/asm/futex.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/arm/include/asm/futex.h	2015-04-26 13:32:22.351684003 -0500
@@ -93,6 +93,8 @@
 	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
+	preempt_disable_rt();
+
 	__asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n"
 	"1:	" TUSER(ldr) "	%1, [%4]\n"
 	"	teq	%1, %2\n"
@@ -104,6 +106,8 @@
 	: "cc", "memory");
 
 	*uval = val;
+
+	preempt_enable_rt();
 	return ret;
 }
 
diff -Nur linux-3.18.12.orig/arch/arm/include/asm/switch_to.h linux-3.18.12/arch/arm/include/asm/switch_to.h
--- linux-3.18.12.orig/arch/arm/include/asm/switch_to.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/arm/include/asm/switch_to.h	2015-04-26 13:32:22.355684003 -0500
@@ -3,6 +3,13 @@
 
 #include <linux/thread_info.h>
 
+#if defined CONFIG_PREEMPT_RT_FULL && defined CONFIG_HIGHMEM
+void switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p);
+#else
+static inline void
+switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p) { }
+#endif
+
 /*
  * For v7 SMP cores running a preemptible kernel we may be pre-empted
  * during a TLB maintenance operation, so execute an inner-shareable dsb
@@ -22,6 +29,7 @@
 
 #define switch_to(prev,next,last)					\
 do {									\
+	switch_kmaps(prev, next);					\
 	last = __switch_to(prev,task_thread_info(prev), task_thread_info(next));	\
 } while (0)
 
diff -Nur linux-3.18.12.orig/arch/arm/include/asm/thread_info.h linux-3.18.12/arch/arm/include/asm/thread_info.h
--- linux-3.18.12.orig/arch/arm/include/asm/thread_info.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/arm/include/asm/thread_info.h	2015-04-26 13:32:22.355684003 -0500
@@ -51,6 +51,7 @@
 struct thread_info {
 	unsigned long		flags;		/* low level flags */
 	int			preempt_count;	/* 0 => preemptable, <0 => bug */
+	int			preempt_lazy_count;	/* 0 => preemptable, <0 => bug */
 	mm_segment_t		addr_limit;	/* address limit */
 	struct task_struct	*task;		/* main task structure */
 	struct exec_domain	*exec_domain;	/* execution domain */
@@ -149,6 +150,7 @@
 #define TIF_SIGPENDING		0
 #define TIF_NEED_RESCHED	1
 #define TIF_NOTIFY_RESUME	2	/* callback before returning to user */
+#define TIF_NEED_RESCHED_LAZY	3
 #define TIF_UPROBE		7
 #define TIF_SYSCALL_TRACE	8
 #define TIF_SYSCALL_AUDIT	9
@@ -162,6 +164,7 @@
 #define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
 #define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
+#define _TIF_NEED_RESCHED_LAZY	(1 << TIF_NEED_RESCHED_LAZY)
 #define _TIF_UPROBE		(1 << TIF_UPROBE)
 #define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)
 #define _TIF_SYSCALL_AUDIT	(1 << TIF_SYSCALL_AUDIT)
diff -Nur linux-3.18.12.orig/arch/arm/Kconfig linux-3.18.12/arch/arm/Kconfig
--- linux-3.18.12.orig/arch/arm/Kconfig	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/arm/Kconfig	2015-04-26 13:32:22.351684003 -0500
@@ -62,6 +62,7 @@
 	select HAVE_PERF_EVENTS
 	select HAVE_PERF_REGS
 	select HAVE_PERF_USER_STACK_DUMP
+	select HAVE_PREEMPT_LAZY
 	select HAVE_RCU_TABLE_FREE if (SMP && ARM_LPAE)
 	select HAVE_REGS_AND_STACK_ACCESS_API
 	select HAVE_SYSCALL_TRACEPOINTS
diff -Nur linux-3.18.12.orig/arch/arm/kernel/asm-offsets.c linux-3.18.12/arch/arm/kernel/asm-offsets.c
--- linux-3.18.12.orig/arch/arm/kernel/asm-offsets.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/arm/kernel/asm-offsets.c	2015-04-26 13:32:22.355684003 -0500
@@ -64,6 +64,7 @@
   BLANK();
   DEFINE(TI_FLAGS,		offsetof(struct thread_info, flags));
   DEFINE(TI_PREEMPT,		offsetof(struct thread_info, preempt_count));
+  DEFINE(TI_PREEMPT_LAZY,	offsetof(struct thread_info, preempt_lazy_count));
   DEFINE(TI_ADDR_LIMIT,		offsetof(struct thread_info, addr_limit));
   DEFINE(TI_TASK,		offsetof(struct thread_info, task));
   DEFINE(TI_EXEC_DOMAIN,	offsetof(struct thread_info, exec_domain));
diff -Nur linux-3.18.12.orig/arch/arm/kernel/entry-armv.S linux-3.18.12/arch/arm/kernel/entry-armv.S
--- linux-3.18.12.orig/arch/arm/kernel/entry-armv.S	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/arm/kernel/entry-armv.S	2015-04-26 13:32:22.355684003 -0500
@@ -207,11 +207,18 @@
 #ifdef CONFIG_PREEMPT
 	get_thread_info tsk
 	ldr	r8, [tsk, #TI_PREEMPT]		@ get preempt count
-	ldr	r0, [tsk, #TI_FLAGS]		@ get flags
 	teq	r8, #0				@ if preempt count != 0
+	bne	1f				@ return from exeption
+	ldr	r0, [tsk, #TI_FLAGS]		@ get flags
+	tst	r0, #_TIF_NEED_RESCHED		@ if NEED_RESCHED is set
+	blne	svc_preempt			@ preempt!
+
+	ldr	r8, [tsk, #TI_PREEMPT_LAZY]	@ get preempt lazy count
+	teq	r8, #0				@ if preempt lazy count != 0
 	movne	r0, #0				@ force flags to 0
-	tst	r0, #_TIF_NEED_RESCHED
+	tst	r0, #_TIF_NEED_RESCHED_LAZY
 	blne	svc_preempt
+1:
 #endif
 
 	svc_exit r5, irq = 1			@ return from exception
@@ -226,6 +233,8 @@
 1:	bl	preempt_schedule_irq		@ irq en/disable is done inside
 	ldr	r0, [tsk, #TI_FLAGS]		@ get new tasks TI_FLAGS
 	tst	r0, #_TIF_NEED_RESCHED
+	bne	1b
+	tst	r0, #_TIF_NEED_RESCHED_LAZY
 	reteq	r8				@ go again
 	b	1b
 #endif
diff -Nur linux-3.18.12.orig/arch/arm/kernel/process.c linux-3.18.12/arch/arm/kernel/process.c
--- linux-3.18.12.orig/arch/arm/kernel/process.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/arm/kernel/process.c	2015-04-26 13:32:22.355684003 -0500
@@ -431,6 +431,30 @@
 }
 
 #ifdef CONFIG_MMU
+/*
+ * CONFIG_SPLIT_PTLOCK_CPUS results in a page->ptl lock.  If the lock is not
+ * initialized by pgtable_page_ctor() then a coredump of the vector page will
+ * fail.
+ */
+static int __init vectors_user_mapping_init_page(void)
+{
+	struct page *page;
+	unsigned long addr = 0xffff0000;
+	pgd_t *pgd;
+	pud_t *pud;
+	pmd_t *pmd;
+
+	pgd = pgd_offset_k(addr);
+	pud = pud_offset(pgd, addr);
+	pmd = pmd_offset(pud, addr);
+	page = pmd_page(*(pmd));
+
+	pgtable_page_ctor(page);
+
+	return 0;
+}
+late_initcall(vectors_user_mapping_init_page);
+
 #ifdef CONFIG_KUSER_HELPERS
 /*
  * The vectors page is always readable from user space for the
diff -Nur linux-3.18.12.orig/arch/arm/kernel/signal.c linux-3.18.12/arch/arm/kernel/signal.c
--- linux-3.18.12.orig/arch/arm/kernel/signal.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/arm/kernel/signal.c	2015-04-26 13:32:22.359684003 -0500
@@ -574,7 +574,8 @@
 do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall)
 {
 	do {
-		if (likely(thread_flags & _TIF_NEED_RESCHED)) {
+		if (likely(thread_flags & (_TIF_NEED_RESCHED |
+					   _TIF_NEED_RESCHED_LAZY))) {
 			schedule();
 		} else {
 			if (unlikely(!user_mode(regs)))
diff -Nur linux-3.18.12.orig/arch/arm/kernel/unwind.c linux-3.18.12/arch/arm/kernel/unwind.c
--- linux-3.18.12.orig/arch/arm/kernel/unwind.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/arm/kernel/unwind.c	2015-04-26 13:32:22.359684003 -0500
@@ -93,7 +93,7 @@
 static const struct unwind_idx *__origin_unwind_idx;
 extern const struct unwind_idx __stop_unwind_idx[];
 
-static DEFINE_SPINLOCK(unwind_lock);
+static DEFINE_RAW_SPINLOCK(unwind_lock);
 static LIST_HEAD(unwind_tables);
 
 /* Convert a prel31 symbol to an absolute address */
@@ -201,7 +201,7 @@
 		/* module unwind tables */
 		struct unwind_table *table;
 
-		spin_lock_irqsave(&unwind_lock, flags);
+		raw_spin_lock_irqsave(&unwind_lock, flags);
 		list_for_each_entry(table, &unwind_tables, list) {
 			if (addr >= table->begin_addr &&
 			    addr < table->end_addr) {
@@ -213,7 +213,7 @@
 				break;
 			}
 		}
-		spin_unlock_irqrestore(&unwind_lock, flags);
+		raw_spin_unlock_irqrestore(&unwind_lock, flags);
 	}
 
 	pr_debug("%s: idx = %p\n", __func__, idx);
@@ -530,9 +530,9 @@
 	tab->begin_addr = text_addr;
 	tab->end_addr = text_addr + text_size;
 
-	spin_lock_irqsave(&unwind_lock, flags);
+	raw_spin_lock_irqsave(&unwind_lock, flags);
 	list_add_tail(&tab->list, &unwind_tables);
-	spin_unlock_irqrestore(&unwind_lock, flags);
+	raw_spin_unlock_irqrestore(&unwind_lock, flags);
 
 	return tab;
 }
@@ -544,9 +544,9 @@
 	if (!tab)
 		return;
 
-	spin_lock_irqsave(&unwind_lock, flags);
+	raw_spin_lock_irqsave(&unwind_lock, flags);
 	list_del(&tab->list);
-	spin_unlock_irqrestore(&unwind_lock, flags);
+	raw_spin_unlock_irqrestore(&unwind_lock, flags);
 
 	kfree(tab);
 }
diff -Nur linux-3.18.12.orig/arch/arm/kvm/arm.c linux-3.18.12/arch/arm/kvm/arm.c
--- linux-3.18.12.orig/arch/arm/kvm/arm.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/arm/kvm/arm.c	2015-04-26 13:32:22.359684003 -0500
@@ -441,9 +441,9 @@
 
 static void vcpu_pause(struct kvm_vcpu *vcpu)
 {
-	wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu);
+	struct swait_head *wq = kvm_arch_vcpu_wq(vcpu);
 
-	wait_event_interruptible(*wq, !vcpu->arch.pause);
+	swait_event_interruptible(*wq, !vcpu->arch.pause);
 }
 
 static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu)
diff -Nur linux-3.18.12.orig/arch/arm/kvm/psci.c linux-3.18.12/arch/arm/kvm/psci.c
--- linux-3.18.12.orig/arch/arm/kvm/psci.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/arm/kvm/psci.c	2015-04-26 13:32:22.359684003 -0500
@@ -66,7 +66,7 @@
 {
 	struct kvm *kvm = source_vcpu->kvm;
 	struct kvm_vcpu *vcpu = NULL, *tmp;
-	wait_queue_head_t *wq;
+	struct swait_head *wq;
 	unsigned long cpu_id;
 	unsigned long context_id;
 	unsigned long mpidr;
@@ -123,7 +123,7 @@
 	smp_mb();		/* Make sure the above is visible */
 
 	wq = kvm_arch_vcpu_wq(vcpu);
-	wake_up_interruptible(wq);
+	swait_wake_interruptible(wq);
 
 	return PSCI_RET_SUCCESS;
 }
diff -Nur linux-3.18.12.orig/arch/arm/mach-at91/at91rm9200_time.c linux-3.18.12/arch/arm/mach-at91/at91rm9200_time.c
--- linux-3.18.12.orig/arch/arm/mach-at91/at91rm9200_time.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/arm/mach-at91/at91rm9200_time.c	2015-04-26 13:32:22.359684003 -0500
@@ -135,6 +135,7 @@
 		break;
 	case CLOCK_EVT_MODE_SHUTDOWN:
 	case CLOCK_EVT_MODE_UNUSED:
+		remove_irq(NR_IRQS_LEGACY + AT91_ID_SYS, &at91rm9200_timer_irq);
 	case CLOCK_EVT_MODE_RESUME:
 		irqmask = 0;
 		break;
diff -Nur linux-3.18.12.orig/arch/arm/mach-exynos/platsmp.c linux-3.18.12/arch/arm/mach-exynos/platsmp.c
--- linux-3.18.12.orig/arch/arm/mach-exynos/platsmp.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/arm/mach-exynos/platsmp.c	2015-04-26 13:32:22.359684003 -0500
@@ -137,7 +137,7 @@
 	return (void __iomem *)(S5P_VA_SCU);
 }
 
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
 
 static void exynos_secondary_init(unsigned int cpu)
 {
@@ -150,8 +150,8 @@
 	/*
 	 * Synchronise with the boot thread.
 	 */
-	spin_lock(&boot_lock);
-	spin_unlock(&boot_lock);
+	raw_spin_lock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 }
 
 static int exynos_boot_secondary(unsigned int cpu, struct task_struct *idle)
@@ -165,7 +165,7 @@
 	 * Set synchronisation state between this boot processor
 	 * and the secondary one
 	 */
-	spin_lock(&boot_lock);
+	raw_spin_lock(&boot_lock);
 
 	/*
 	 * The secondary processor is waiting to be released from
@@ -192,7 +192,7 @@
 
 		if (timeout == 0) {
 			printk(KERN_ERR "cpu1 power enable failed");
-			spin_unlock(&boot_lock);
+			raw_spin_unlock(&boot_lock);
 			return -ETIMEDOUT;
 		}
 	}
@@ -242,7 +242,7 @@
 	 * calibrations, then wait for it to finish
 	 */
 fail:
-	spin_unlock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 
 	return pen_release != -1 ? ret : 0;
 }
diff -Nur linux-3.18.12.orig/arch/arm/mach-hisi/platmcpm.c linux-3.18.12/arch/arm/mach-hisi/platmcpm.c
--- linux-3.18.12.orig/arch/arm/mach-hisi/platmcpm.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/arm/mach-hisi/platmcpm.c	2015-04-26 13:32:22.363684003 -0500
@@ -57,7 +57,7 @@
 
 static void __iomem *sysctrl, *fabric;
 static int hip04_cpu_table[HIP04_MAX_CLUSTERS][HIP04_MAX_CPUS_PER_CLUSTER];
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
 static u32 fabric_phys_addr;
 /*
  * [0]: bootwrapper physical address
@@ -104,7 +104,7 @@
 	if (cluster >= HIP04_MAX_CLUSTERS || cpu >= HIP04_MAX_CPUS_PER_CLUSTER)
 		return -EINVAL;
 
-	spin_lock_irq(&boot_lock);
+	raw_spin_lock_irq(&boot_lock);
 
 	if (hip04_cpu_table[cluster][cpu])
 		goto out;
@@ -133,7 +133,7 @@
 	udelay(20);
 out:
 	hip04_cpu_table[cluster][cpu]++;
-	spin_unlock_irq(&boot_lock);
+	raw_spin_unlock_irq(&boot_lock);
 
 	return 0;
 }
@@ -149,7 +149,7 @@
 
 	__mcpm_cpu_going_down(cpu, cluster);
 
-	spin_lock(&boot_lock);
+	raw_spin_lock(&boot_lock);
 	BUG_ON(__mcpm_cluster_state(cluster) != CLUSTER_UP);
 	hip04_cpu_table[cluster][cpu]--;
 	if (hip04_cpu_table[cluster][cpu] == 1) {
@@ -162,7 +162,7 @@
 
 	last_man = hip04_cluster_is_down(cluster);
 	if (last_man && __mcpm_outbound_enter_critical(cpu, cluster)) {
-		spin_unlock(&boot_lock);
+		raw_spin_unlock(&boot_lock);
 		/* Since it's Cortex A15, disable L2 prefetching. */
 		asm volatile(
 		"mcr	p15, 1, %0, c15, c0, 3 \n\t"
@@ -173,7 +173,7 @@
 		hip04_set_snoop_filter(cluster, 0);
 		__mcpm_outbound_leave_critical(cluster, CLUSTER_DOWN);
 	} else {
-		spin_unlock(&boot_lock);
+		raw_spin_unlock(&boot_lock);
 		v7_exit_coherency_flush(louis);
 	}
 
@@ -192,7 +192,7 @@
 	       cpu >= HIP04_MAX_CPUS_PER_CLUSTER);
 
 	count = TIMEOUT_MSEC / POLL_MSEC;
-	spin_lock_irq(&boot_lock);
+	raw_spin_lock_irq(&boot_lock);
 	for (tries = 0; tries < count; tries++) {
 		if (hip04_cpu_table[cluster][cpu]) {
 			ret = -EBUSY;
@@ -202,10 +202,10 @@
 		data = readl_relaxed(sysctrl + SC_CPU_RESET_STATUS(cluster));
 		if (data & CORE_WFI_STATUS(cpu))
 			break;
-		spin_unlock_irq(&boot_lock);
+		raw_spin_unlock_irq(&boot_lock);
 		/* Wait for clean L2 when the whole cluster is down. */
 		msleep(POLL_MSEC);
-		spin_lock_irq(&boot_lock);
+		raw_spin_lock_irq(&boot_lock);
 	}
 	if (tries >= count)
 		goto err;
@@ -220,10 +220,10 @@
 	}
 	if (tries >= count)
 		goto err;
-	spin_unlock_irq(&boot_lock);
+	raw_spin_unlock_irq(&boot_lock);
 	return 0;
 err:
-	spin_unlock_irq(&boot_lock);
+	raw_spin_unlock_irq(&boot_lock);
 	return ret;
 }
 
@@ -235,10 +235,10 @@
 	cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
 	cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
 
-	spin_lock(&boot_lock);
+	raw_spin_lock(&boot_lock);
 	if (!hip04_cpu_table[cluster][cpu])
 		hip04_cpu_table[cluster][cpu] = 1;
-	spin_unlock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 }
 
 static void __naked hip04_mcpm_power_up_setup(unsigned int affinity_level)
diff -Nur linux-3.18.12.orig/arch/arm/mach-omap2/omap-smp.c linux-3.18.12/arch/arm/mach-omap2/omap-smp.c
--- linux-3.18.12.orig/arch/arm/mach-omap2/omap-smp.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/arm/mach-omap2/omap-smp.c	2015-04-26 13:32:22.363684003 -0500
@@ -43,7 +43,7 @@
 /* SCU base address */
 static void __iomem *scu_base;
 
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
 
 void __iomem *omap4_get_scu_base(void)
 {
@@ -74,8 +74,8 @@
 	/*
 	 * Synchronise with the boot thread.
 	 */
-	spin_lock(&boot_lock);
-	spin_unlock(&boot_lock);
+	raw_spin_lock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 }
 
 static int omap4_boot_secondary(unsigned int cpu, struct task_struct *idle)
@@ -89,7 +89,7 @@
 	 * Set synchronisation state between this boot processor
 	 * and the secondary one
 	 */
-	spin_lock(&boot_lock);
+	raw_spin_lock(&boot_lock);
 
 	/*
 	 * Update the AuxCoreBoot0 with boot state for secondary core.
@@ -166,7 +166,7 @@
 	 * Now the secondary core is starting up let it run its
 	 * calibrations, then wait for it to finish
 	 */
-	spin_unlock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 
 	return 0;
 }
diff -Nur linux-3.18.12.orig/arch/arm/mach-prima2/platsmp.c linux-3.18.12/arch/arm/mach-prima2/platsmp.c
--- linux-3.18.12.orig/arch/arm/mach-prima2/platsmp.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/arm/mach-prima2/platsmp.c	2015-04-26 13:32:22.363684003 -0500
@@ -23,7 +23,7 @@
 static void __iomem *scu_base;
 static void __iomem *rsc_base;
 
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
 
 static struct map_desc scu_io_desc __initdata = {
 	.length		= SZ_4K,
@@ -56,8 +56,8 @@
 	/*
 	 * Synchronise with the boot thread.
 	 */
-	spin_lock(&boot_lock);
-	spin_unlock(&boot_lock);
+	raw_spin_lock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 }
 
 static struct of_device_id rsc_ids[]  = {
@@ -95,7 +95,7 @@
 	/* make sure write buffer is drained */
 	mb();
 
-	spin_lock(&boot_lock);
+	raw_spin_lock(&boot_lock);
 
 	/*
 	 * The secondary processor is waiting to be released from
@@ -127,7 +127,7 @@
 	 * now the secondary core is starting up let it run its
 	 * calibrations, then wait for it to finish
 	 */
-	spin_unlock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 
 	return pen_release != -1 ? -ENOSYS : 0;
 }
diff -Nur linux-3.18.12.orig/arch/arm/mach-qcom/platsmp.c linux-3.18.12/arch/arm/mach-qcom/platsmp.c
--- linux-3.18.12.orig/arch/arm/mach-qcom/platsmp.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/arm/mach-qcom/platsmp.c	2015-04-26 13:32:22.363684003 -0500
@@ -46,7 +46,7 @@
 
 extern void secondary_startup(void);
 
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
 
 #ifdef CONFIG_HOTPLUG_CPU
 static void __ref qcom_cpu_die(unsigned int cpu)
@@ -60,8 +60,8 @@
 	/*
 	 * Synchronise with the boot thread.
 	 */
-	spin_lock(&boot_lock);
-	spin_unlock(&boot_lock);
+	raw_spin_lock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 }
 
 static int scss_release_secondary(unsigned int cpu)
@@ -284,7 +284,7 @@
 	 * set synchronisation state between this boot processor
 	 * and the secondary one
 	 */
-	spin_lock(&boot_lock);
+	raw_spin_lock(&boot_lock);
 
 	/*
 	 * Send the secondary CPU a soft interrupt, thereby causing
@@ -297,7 +297,7 @@
 	 * now the secondary core is starting up let it run its
 	 * calibrations, then wait for it to finish
 	 */
-	spin_unlock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 
 	return ret;
 }
diff -Nur linux-3.18.12.orig/arch/arm/mach-spear/platsmp.c linux-3.18.12/arch/arm/mach-spear/platsmp.c
--- linux-3.18.12.orig/arch/arm/mach-spear/platsmp.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/arm/mach-spear/platsmp.c	2015-04-26 13:32:22.363684003 -0500
@@ -32,7 +32,7 @@
 	sync_cache_w(&pen_release);
 }
 
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
 
 static void __iomem *scu_base = IOMEM(VA_SCU_BASE);
 
@@ -47,8 +47,8 @@
 	/*
 	 * Synchronise with the boot thread.
 	 */
-	spin_lock(&boot_lock);
-	spin_unlock(&boot_lock);
+	raw_spin_lock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 }
 
 static int spear13xx_boot_secondary(unsigned int cpu, struct task_struct *idle)
@@ -59,7 +59,7 @@
 	 * set synchronisation state between this boot processor
 	 * and the secondary one
 	 */
-	spin_lock(&boot_lock);
+	raw_spin_lock(&boot_lock);
 
 	/*
 	 * The secondary processor is waiting to be released from
@@ -84,7 +84,7 @@
 	 * now the secondary core is starting up let it run its
 	 * calibrations, then wait for it to finish
 	 */
-	spin_unlock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 
 	return pen_release != -1 ? -ENOSYS : 0;
 }
diff -Nur linux-3.18.12.orig/arch/arm/mach-sti/platsmp.c linux-3.18.12/arch/arm/mach-sti/platsmp.c
--- linux-3.18.12.orig/arch/arm/mach-sti/platsmp.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/arm/mach-sti/platsmp.c	2015-04-26 13:32:22.363684003 -0500
@@ -34,7 +34,7 @@
 	sync_cache_w(&pen_release);
 }
 
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
 
 static void sti_secondary_init(unsigned int cpu)
 {
@@ -49,8 +49,8 @@
 	/*
 	 * Synchronise with the boot thread.
 	 */
-	spin_lock(&boot_lock);
-	spin_unlock(&boot_lock);
+	raw_spin_lock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 }
 
 static int sti_boot_secondary(unsigned int cpu, struct task_struct *idle)
@@ -61,7 +61,7 @@
 	 * set synchronisation state between this boot processor
 	 * and the secondary one
 	 */
-	spin_lock(&boot_lock);
+	raw_spin_lock(&boot_lock);
 
 	/*
 	 * The secondary processor is waiting to be released from
@@ -92,7 +92,7 @@
 	 * now the secondary core is starting up let it run its
 	 * calibrations, then wait for it to finish
 	 */
-	spin_unlock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 
 	return pen_release != -1 ? -ENOSYS : 0;
 }
diff -Nur linux-3.18.12.orig/arch/arm/mach-ux500/platsmp.c linux-3.18.12/arch/arm/mach-ux500/platsmp.c
--- linux-3.18.12.orig/arch/arm/mach-ux500/platsmp.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/arm/mach-ux500/platsmp.c	2015-04-26 13:32:22.363684003 -0500
@@ -51,7 +51,7 @@
 	return NULL;
 }
 
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
 
 static void ux500_secondary_init(unsigned int cpu)
 {
@@ -64,8 +64,8 @@
 	/*
 	 * Synchronise with the boot thread.
 	 */
-	spin_lock(&boot_lock);
-	spin_unlock(&boot_lock);
+	raw_spin_lock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 }
 
 static int ux500_boot_secondary(unsigned int cpu, struct task_struct *idle)
@@ -76,7 +76,7 @@
 	 * set synchronisation state between this boot processor
 	 * and the secondary one
 	 */
-	spin_lock(&boot_lock);
+	raw_spin_lock(&boot_lock);
 
 	/*
 	 * The secondary processor is waiting to be released from
@@ -97,7 +97,7 @@
 	 * now the secondary core is starting up let it run its
 	 * calibrations, then wait for it to finish
 	 */
-	spin_unlock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 
 	return pen_release != -1 ? -ENOSYS : 0;
 }
diff -Nur linux-3.18.12.orig/arch/arm/mm/fault.c linux-3.18.12/arch/arm/mm/fault.c
--- linux-3.18.12.orig/arch/arm/mm/fault.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/arm/mm/fault.c	2015-04-26 13:32:22.367684003 -0500
@@ -277,7 +277,7 @@
 	 * If we're in an interrupt or have no user
 	 * context, we must not take the fault..
 	 */
-	if (in_atomic() || !mm)
+	if (!mm || pagefault_disabled())
 		goto no_context;
 
 	if (user_mode(regs))
@@ -431,6 +431,9 @@
 	if (addr < TASK_SIZE)
 		return do_page_fault(addr, fsr, regs);
 
+	if (interrupts_enabled(regs))
+		local_irq_enable();
+
 	if (user_mode(regs))
 		goto bad_area;
 
@@ -498,6 +501,9 @@
 static int
 do_sect_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 {
+	if (interrupts_enabled(regs))
+		local_irq_enable();
+
 	do_bad_area(addr, fsr, regs);
 	return 0;
 }
diff -Nur linux-3.18.12.orig/arch/arm/mm/highmem.c linux-3.18.12/arch/arm/mm/highmem.c
--- linux-3.18.12.orig/arch/arm/mm/highmem.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/arm/mm/highmem.c	2015-04-26 13:32:22.367684003 -0500
@@ -53,6 +53,7 @@
 
 void *kmap_atomic(struct page *page)
 {
+	pte_t pte = mk_pte(page, kmap_prot);
 	unsigned int idx;
 	unsigned long vaddr;
 	void *kmap;
@@ -91,7 +92,10 @@
 	 * in place, so the contained TLB flush ensures the TLB is updated
 	 * with the new mapping.
 	 */
-	set_fixmap_pte(idx, mk_pte(page, kmap_prot));
+#ifdef CONFIG_PREEMPT_RT_FULL
+	current->kmap_pte[type] = pte;
+#endif
+	set_fixmap_pte(idx, pte);
 
 	return (void *)vaddr;
 }
@@ -108,12 +112,15 @@
 
 		if (cache_is_vivt())
 			__cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE);
+#ifdef CONFIG_PREEMPT_RT_FULL
+		current->kmap_pte[type] = __pte(0);
+#endif
 #ifdef CONFIG_DEBUG_HIGHMEM
 		BUG_ON(vaddr != __fix_to_virt(idx));
-		set_fixmap_pte(idx, __pte(0));
 #else
 		(void) idx;  /* to kill a warning */
 #endif
+		set_fixmap_pte(idx, __pte(0));
 		kmap_atomic_idx_pop();
 	} else if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) {
 		/* this address was obtained through kmap_high_get() */
@@ -125,6 +132,7 @@
 
 void *kmap_atomic_pfn(unsigned long pfn)
 {
+	pte_t pte = pfn_pte(pfn, kmap_prot);
 	unsigned long vaddr;
 	int idx, type;
 	struct page *page = pfn_to_page(pfn);
@@ -139,7 +147,10 @@
 #ifdef CONFIG_DEBUG_HIGHMEM
 	BUG_ON(!pte_none(*(fixmap_page_table + idx)));
 #endif
-	set_fixmap_pte(idx, pfn_pte(pfn, kmap_prot));
+#ifdef CONFIG_PREEMPT_RT_FULL
+	current->kmap_pte[type] = pte;
+#endif
+	set_fixmap_pte(idx, pte);
 
 	return (void *)vaddr;
 }
@@ -153,3 +164,28 @@
 
 	return pte_page(get_fixmap_pte(vaddr));
 }
+
+#if defined CONFIG_PREEMPT_RT_FULL
+void switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p)
+{
+	int i;
+
+	/*
+	 * Clear @prev's kmap_atomic mappings
+	 */
+	for (i = 0; i < prev_p->kmap_idx; i++) {
+		int idx = i + KM_TYPE_NR * smp_processor_id();
+
+		set_fixmap_pte(idx, __pte(0));
+	}
+	/*
+	 * Restore @next_p's kmap_atomic mappings
+	 */
+	for (i = 0; i < next_p->kmap_idx; i++) {
+		int idx = i + KM_TYPE_NR * smp_processor_id();
+
+		if (!pte_none(next_p->kmap_pte[i]))
+			set_fixmap_pte(idx, next_p->kmap_pte[i]);
+	}
+}
+#endif
diff -Nur linux-3.18.12.orig/arch/arm/plat-versatile/platsmp.c linux-3.18.12/arch/arm/plat-versatile/platsmp.c
--- linux-3.18.12.orig/arch/arm/plat-versatile/platsmp.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/arm/plat-versatile/platsmp.c	2015-04-26 13:32:22.367684003 -0500
@@ -30,7 +30,7 @@
 	sync_cache_w(&pen_release);
 }
 
-static DEFINE_SPINLOCK(boot_lock);
+static DEFINE_RAW_SPINLOCK(boot_lock);
 
 void versatile_secondary_init(unsigned int cpu)
 {
@@ -43,8 +43,8 @@
 	/*
 	 * Synchronise with the boot thread.
 	 */
-	spin_lock(&boot_lock);
-	spin_unlock(&boot_lock);
+	raw_spin_lock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 }
 
 int versatile_boot_secondary(unsigned int cpu, struct task_struct *idle)
@@ -55,7 +55,7 @@
 	 * Set synchronisation state between this boot processor
 	 * and the secondary one
 	 */
-	spin_lock(&boot_lock);
+	raw_spin_lock(&boot_lock);
 
 	/*
 	 * This is really belt and braces; we hold unintended secondary
@@ -85,7 +85,7 @@
 	 * now the secondary core is starting up let it run its
 	 * calibrations, then wait for it to finish
 	 */
-	spin_unlock(&boot_lock);
+	raw_spin_unlock(&boot_lock);
 
 	return pen_release != -1 ? -ENOSYS : 0;
 }
diff -Nur linux-3.18.12.orig/arch/avr32/mm/fault.c linux-3.18.12/arch/avr32/mm/fault.c
--- linux-3.18.12.orig/arch/avr32/mm/fault.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/avr32/mm/fault.c	2015-04-26 13:32:22.367684003 -0500
@@ -81,7 +81,7 @@
 	 * If we're in an interrupt or have no user context, we must
 	 * not take the fault...
 	 */
-	if (in_atomic() || !mm || regs->sr & SYSREG_BIT(GM))
+	if (!mm || regs->sr & SYSREG_BIT(GM) || pagefault_disabled())
 		goto no_context;
 
 	local_irq_enable();
diff -Nur linux-3.18.12.orig/arch/cris/mm/fault.c linux-3.18.12/arch/cris/mm/fault.c
--- linux-3.18.12.orig/arch/cris/mm/fault.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/cris/mm/fault.c	2015-04-26 13:32:22.367684003 -0500
@@ -113,7 +113,7 @@
 	 * user context, we must not take the fault.
 	 */
 
-	if (in_atomic() || !mm)
+	if (!mm || pagefault_disabled())
 		goto no_context;
 
 	if (user_mode(regs))
diff -Nur linux-3.18.12.orig/arch/frv/mm/fault.c linux-3.18.12/arch/frv/mm/fault.c
--- linux-3.18.12.orig/arch/frv/mm/fault.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/frv/mm/fault.c	2015-04-26 13:32:22.367684003 -0500
@@ -78,7 +78,7 @@
 	 * If we're in an interrupt or have no user
 	 * context, we must not take the fault..
 	 */
-	if (in_atomic() || !mm)
+	if (!mm || pagefault_disabled())
 		goto no_context;
 
 	if (user_mode(__frame))
diff -Nur linux-3.18.12.orig/arch/ia64/mm/fault.c linux-3.18.12/arch/ia64/mm/fault.c
--- linux-3.18.12.orig/arch/ia64/mm/fault.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/ia64/mm/fault.c	2015-04-26 13:32:22.367684003 -0500
@@ -96,7 +96,7 @@
 	/*
 	 * If we're in an interrupt or have no user context, we must not take the fault..
 	 */
-	if (in_atomic() || !mm)
+	if (!mm || pagefault_disabled())
 		goto no_context;
 
 #ifdef CONFIG_VIRTUAL_MEM_MAP
diff -Nur linux-3.18.12.orig/arch/Kconfig linux-3.18.12/arch/Kconfig
--- linux-3.18.12.orig/arch/Kconfig	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/Kconfig	2015-04-26 13:32:22.351684003 -0500
@@ -6,6 +6,7 @@
 	tristate "OProfile system profiling"
 	depends on PROFILING
 	depends on HAVE_OPROFILE
+	depends on !PREEMPT_RT_FULL
 	select RING_BUFFER
 	select RING_BUFFER_ALLOW_SWAP
 	help
diff -Nur linux-3.18.12.orig/arch/m32r/mm/fault.c linux-3.18.12/arch/m32r/mm/fault.c
--- linux-3.18.12.orig/arch/m32r/mm/fault.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/m32r/mm/fault.c	2015-04-26 13:32:22.367684003 -0500
@@ -114,7 +114,7 @@
 	 * If we're in an interrupt or have no user context or are running in an
 	 * atomic region then we must not take the fault..
 	 */
-	if (in_atomic() || !mm)
+	if (!mm || pagefault_disabled())
 		goto bad_area_nosemaphore;
 
 	if (error_code & ACE_USERMODE)
diff -Nur linux-3.18.12.orig/arch/m68k/mm/fault.c linux-3.18.12/arch/m68k/mm/fault.c
--- linux-3.18.12.orig/arch/m68k/mm/fault.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/m68k/mm/fault.c	2015-04-26 13:32:22.367684003 -0500
@@ -81,7 +81,7 @@
 	 * If we're in an interrupt or have no user
 	 * context, we must not take the fault..
 	 */
-	if (in_atomic() || !mm)
+	if (!mm || pagefault_disabled())
 		goto no_context;
 
 	if (user_mode(regs))
diff -Nur linux-3.18.12.orig/arch/microblaze/mm/fault.c linux-3.18.12/arch/microblaze/mm/fault.c
--- linux-3.18.12.orig/arch/microblaze/mm/fault.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/microblaze/mm/fault.c	2015-04-26 13:32:22.367684003 -0500
@@ -107,7 +107,7 @@
 	if ((error_code & 0x13) == 0x13 || (error_code & 0x11) == 0x11)
 		is_write = 0;
 
-	if (unlikely(in_atomic() || !mm)) {
+	if (unlikely(!mm || pagefault_disabled())) {
 		if (kernel_mode(regs))
 			goto bad_area_nosemaphore;
 
diff -Nur linux-3.18.12.orig/arch/mips/Kconfig linux-3.18.12/arch/mips/Kconfig
--- linux-3.18.12.orig/arch/mips/Kconfig	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/mips/Kconfig	2015-04-26 13:32:22.367684003 -0500
@@ -2196,7 +2196,7 @@
 #
 config HIGHMEM
 	bool "High Memory Support"
-	depends on 32BIT && CPU_SUPPORTS_HIGHMEM && SYS_SUPPORTS_HIGHMEM && !CPU_MIPS32_3_5_EVA
+	depends on 32BIT && CPU_SUPPORTS_HIGHMEM && SYS_SUPPORTS_HIGHMEM && !CPU_MIPS32_3_5_EVA && !PREEMPT_RT_FULL
 
 config CPU_SUPPORTS_HIGHMEM
 	bool
diff -Nur linux-3.18.12.orig/arch/mips/kernel/signal.c linux-3.18.12/arch/mips/kernel/signal.c
--- linux-3.18.12.orig/arch/mips/kernel/signal.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/mips/kernel/signal.c	2015-04-26 13:32:22.367684003 -0500
@@ -613,6 +613,7 @@
 	__u32 thread_info_flags)
 {
 	local_irq_enable();
+	preempt_check_resched();
 
 	user_exit();
 
diff -Nur linux-3.18.12.orig/arch/mips/mm/fault.c linux-3.18.12/arch/mips/mm/fault.c
--- linux-3.18.12.orig/arch/mips/mm/fault.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/mips/mm/fault.c	2015-04-26 13:32:22.367684003 -0500
@@ -89,7 +89,7 @@
 	 * If we're in an interrupt or have no user
 	 * context, we must not take the fault..
 	 */
-	if (in_atomic() || !mm)
+	if (!mm || pagefault_disabled())
 		goto bad_area_nosemaphore;
 
 	if (user_mode(regs))
diff -Nur linux-3.18.12.orig/arch/mips/mm/init.c linux-3.18.12/arch/mips/mm/init.c
--- linux-3.18.12.orig/arch/mips/mm/init.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/mips/mm/init.c	2015-04-26 13:32:22.367684003 -0500
@@ -90,7 +90,7 @@
 
 	BUG_ON(Page_dcache_dirty(page));
 
-	pagefault_disable();
+	raw_pagefault_disable();
 	idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
 	idx += in_interrupt() ? FIX_N_COLOURS : 0;
 	vaddr = __fix_to_virt(FIX_CMAP_END - idx);
@@ -146,7 +146,7 @@
 	tlbw_use_hazard();
 	write_c0_entryhi(old_ctx);
 	local_irq_restore(flags);
-	pagefault_enable();
+	raw_pagefault_enable();
 }
 
 void copy_user_highpage(struct page *to, struct page *from,
diff -Nur linux-3.18.12.orig/arch/mn10300/mm/fault.c linux-3.18.12/arch/mn10300/mm/fault.c
--- linux-3.18.12.orig/arch/mn10300/mm/fault.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/mn10300/mm/fault.c	2015-04-26 13:32:22.367684003 -0500
@@ -168,7 +168,7 @@
 	 * If we're in an interrupt or have no user
 	 * context, we must not take the fault..
 	 */
-	if (in_atomic() || !mm)
+	if (!mm || pagefault_disabled())
 		goto no_context;
 
 	if ((fault_code & MMUFCR_xFC_ACCESS) == MMUFCR_xFC_ACCESS_USR)
diff -Nur linux-3.18.12.orig/arch/parisc/mm/fault.c linux-3.18.12/arch/parisc/mm/fault.c
--- linux-3.18.12.orig/arch/parisc/mm/fault.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/parisc/mm/fault.c	2015-04-26 13:32:22.367684003 -0500
@@ -207,7 +207,7 @@
 	int fault;
 	unsigned int flags;
 
-	if (in_atomic())
+	if (pagefault_disabled())
 		goto no_context;
 
 	tsk = current;
diff -Nur linux-3.18.12.orig/arch/powerpc/include/asm/kvm_host.h linux-3.18.12/arch/powerpc/include/asm/kvm_host.h
--- linux-3.18.12.orig/arch/powerpc/include/asm/kvm_host.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/powerpc/include/asm/kvm_host.h	2015-04-26 13:32:22.367684003 -0500
@@ -296,7 +296,7 @@
 	u8 in_guest;
 	struct list_head runnable_threads;
 	spinlock_t lock;
-	wait_queue_head_t wq;
+	struct swait_head wq;
 	u64 stolen_tb;
 	u64 preempt_tb;
 	struct kvm_vcpu *runner;
@@ -618,7 +618,7 @@
 	u8 prodded;
 	u32 last_inst;
 
-	wait_queue_head_t *wqp;
+	struct swait_head *wqp;
 	struct kvmppc_vcore *vcore;
 	int ret;
 	int trap;
diff -Nur linux-3.18.12.orig/arch/powerpc/include/asm/thread_info.h linux-3.18.12/arch/powerpc/include/asm/thread_info.h
--- linux-3.18.12.orig/arch/powerpc/include/asm/thread_info.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/powerpc/include/asm/thread_info.h	2015-04-26 13:32:22.367684003 -0500
@@ -43,6 +43,8 @@
 	int		cpu;			/* cpu we're on */
 	int		preempt_count;		/* 0 => preemptable,
 						   <0 => BUG */
+	int		preempt_lazy_count;	/* 0 => preemptable,
+						   <0 => BUG */
 	struct restart_block restart_block;
 	unsigned long	local_flags;		/* private flags for thread */
 
@@ -88,8 +90,7 @@
 #define TIF_SYSCALL_TRACE	0	/* syscall trace active */
 #define TIF_SIGPENDING		1	/* signal pending */
 #define TIF_NEED_RESCHED	2	/* rescheduling necessary */
-#define TIF_POLLING_NRFLAG	3	/* true if poll_idle() is polling
-					   TIF_NEED_RESCHED */
+#define TIF_NEED_RESCHED_LAZY	3	/* lazy rescheduling necessary */
 #define TIF_32BIT		4	/* 32 bit binary */
 #define TIF_RESTORE_TM		5	/* need to restore TM FP/VEC/VSX */
 #define TIF_SYSCALL_AUDIT	7	/* syscall auditing active */
@@ -107,6 +108,8 @@
 #if defined(CONFIG_PPC64)
 #define TIF_ELF2ABI		18	/* function descriptors must die! */
 #endif
+#define TIF_POLLING_NRFLAG	19	/* true if poll_idle() is polling
+					   TIF_NEED_RESCHED */
 
 /* as above, but as bit values */
 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
@@ -125,14 +128,16 @@
 #define _TIF_SYSCALL_TRACEPOINT	(1<<TIF_SYSCALL_TRACEPOINT)
 #define _TIF_EMULATE_STACK_STORE	(1<<TIF_EMULATE_STACK_STORE)
 #define _TIF_NOHZ		(1<<TIF_NOHZ)
+#define _TIF_NEED_RESCHED_LAZY	(1<<TIF_NEED_RESCHED_LAZY)
 #define _TIF_SYSCALL_T_OR_A	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
 				 _TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT | \
 				 _TIF_NOHZ)
 
 #define _TIF_USER_WORK_MASK	(_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
 				 _TIF_NOTIFY_RESUME | _TIF_UPROBE | \
-				 _TIF_RESTORE_TM)
+				 _TIF_RESTORE_TM | _TIF_NEED_RESCHED_LAZY)
 #define _TIF_PERSYSCALL_MASK	(_TIF_RESTOREALL|_TIF_NOERROR)
+#define _TIF_NEED_RESCHED_MASK	(_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY)
 
 /* Bits in local_flags */
 /* Don't move TLF_NAPPING without adjusting the code in entry_32.S */
diff -Nur linux-3.18.12.orig/arch/powerpc/Kconfig linux-3.18.12/arch/powerpc/Kconfig
--- linux-3.18.12.orig/arch/powerpc/Kconfig	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/powerpc/Kconfig	2015-04-26 13:32:22.367684003 -0500
@@ -60,10 +60,11 @@
 
 config RWSEM_GENERIC_SPINLOCK
 	bool
+	default y if PREEMPT_RT_FULL
 
 config RWSEM_XCHGADD_ALGORITHM
 	bool
-	default y
+	default y if !PREEMPT_RT_FULL
 
 config GENERIC_LOCKBREAK
 	bool
@@ -136,6 +137,7 @@
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
 	select GENERIC_STRNCPY_FROM_USER
 	select GENERIC_STRNLEN_USER
+	select HAVE_PREEMPT_LAZY
 	select HAVE_MOD_ARCH_SPECIFIC
 	select MODULES_USE_ELF_RELA
 	select CLONE_BACKWARDS
@@ -303,7 +305,7 @@
 
 config HIGHMEM
 	bool "High memory support"
-	depends on PPC32
+	depends on PPC32 && !PREEMPT_RT_FULL
 
 source kernel/Kconfig.hz
 source kernel/Kconfig.preempt
diff -Nur linux-3.18.12.orig/arch/powerpc/kernel/asm-offsets.c linux-3.18.12/arch/powerpc/kernel/asm-offsets.c
--- linux-3.18.12.orig/arch/powerpc/kernel/asm-offsets.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/powerpc/kernel/asm-offsets.c	2015-04-26 13:32:22.371684003 -0500
@@ -159,6 +159,7 @@
 	DEFINE(TI_FLAGS, offsetof(struct thread_info, flags));
 	DEFINE(TI_LOCAL_FLAGS, offsetof(struct thread_info, local_flags));
 	DEFINE(TI_PREEMPT, offsetof(struct thread_info, preempt_count));
+	DEFINE(TI_PREEMPT_LAZY, offsetof(struct thread_info, preempt_lazy_count));
 	DEFINE(TI_TASK, offsetof(struct thread_info, task));
 	DEFINE(TI_CPU, offsetof(struct thread_info, cpu));
 
diff -Nur linux-3.18.12.orig/arch/powerpc/kernel/entry_32.S linux-3.18.12/arch/powerpc/kernel/entry_32.S
--- linux-3.18.12.orig/arch/powerpc/kernel/entry_32.S	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/powerpc/kernel/entry_32.S	2015-04-26 13:32:22.371684003 -0500
@@ -890,7 +890,14 @@
 	cmpwi	0,r0,0		/* if non-zero, just restore regs and return */
 	bne	restore
 	andi.	r8,r8,_TIF_NEED_RESCHED
+	bne+	1f
+	lwz	r0,TI_PREEMPT_LAZY(r9)
+	cmpwi	0,r0,0		/* if non-zero, just restore regs and return */
+	bne	restore
+	lwz	r0,TI_FLAGS(r9)
+	andi.	r0,r0,_TIF_NEED_RESCHED_LAZY
 	beq+	restore
+1:
 	lwz	r3,_MSR(r1)
 	andi.	r0,r3,MSR_EE	/* interrupts off? */
 	beq	restore		/* don't schedule if so */
@@ -901,11 +908,11 @@
 	 */
 	bl	trace_hardirqs_off
 #endif
-1:	bl	preempt_schedule_irq
+2:	bl	preempt_schedule_irq
 	CURRENT_THREAD_INFO(r9, r1)
 	lwz	r3,TI_FLAGS(r9)
-	andi.	r0,r3,_TIF_NEED_RESCHED
-	bne-	1b
+	andi.	r0,r3,_TIF_NEED_RESCHED_MASK
+	bne-	2b
 #ifdef CONFIG_TRACE_IRQFLAGS
 	/* And now, to properly rebalance the above, we tell lockdep they
 	 * are being turned back on, which will happen when we return
@@ -1226,7 +1233,7 @@
 #endif /* !(CONFIG_4xx || CONFIG_BOOKE) */
 
 do_work:			/* r10 contains MSR_KERNEL here */
-	andi.	r0,r9,_TIF_NEED_RESCHED
+	andi.	r0,r9,_TIF_NEED_RESCHED_MASK
 	beq	do_user_signal
 
 do_resched:			/* r10 contains MSR_KERNEL here */
@@ -1247,7 +1254,7 @@
 	MTMSRD(r10)		/* disable interrupts */
 	CURRENT_THREAD_INFO(r9, r1)
 	lwz	r9,TI_FLAGS(r9)
-	andi.	r0,r9,_TIF_NEED_RESCHED
+	andi.	r0,r9,_TIF_NEED_RESCHED_MASK
 	bne-	do_resched
 	andi.	r0,r9,_TIF_USER_WORK_MASK
 	beq	restore_user
diff -Nur linux-3.18.12.orig/arch/powerpc/kernel/entry_64.S linux-3.18.12/arch/powerpc/kernel/entry_64.S
--- linux-3.18.12.orig/arch/powerpc/kernel/entry_64.S	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/powerpc/kernel/entry_64.S	2015-04-26 13:32:22.371684003 -0500
@@ -644,7 +644,7 @@
 #else
 	beq	restore
 #endif
-1:	andi.	r0,r4,_TIF_NEED_RESCHED
+1:	andi.	r0,r4,_TIF_NEED_RESCHED_MASK
 	beq	2f
 	bl	restore_interrupts
 	SCHEDULE_USER
@@ -706,10 +706,18 @@
 
 #ifdef CONFIG_PREEMPT
 	/* Check if we need to preempt */
+	lwz	r8,TI_PREEMPT(r9)
+	cmpwi	0,r8,0		/* if non-zero, just restore regs and return */
+	bne	restore
 	andi.	r0,r4,_TIF_NEED_RESCHED
+	bne+	check_count
+
+	andi.	r0,r4,_TIF_NEED_RESCHED_LAZY
 	beq+	restore
+	lwz	r8,TI_PREEMPT_LAZY(r9)
+
 	/* Check that preempt_count() == 0 and interrupts are enabled */
-	lwz	r8,TI_PREEMPT(r9)
+check_count:
 	cmpwi	cr1,r8,0
 	ld	r0,SOFTE(r1)
 	cmpdi	r0,0
@@ -726,7 +734,7 @@
 	/* Re-test flags and eventually loop */
 	CURRENT_THREAD_INFO(r9, r1)
 	ld	r4,TI_FLAGS(r9)
-	andi.	r0,r4,_TIF_NEED_RESCHED
+	andi.	r0,r4,_TIF_NEED_RESCHED_MASK
 	bne	1b
 
 	/*
diff -Nur linux-3.18.12.orig/arch/powerpc/kernel/irq.c linux-3.18.12/arch/powerpc/kernel/irq.c
--- linux-3.18.12.orig/arch/powerpc/kernel/irq.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/powerpc/kernel/irq.c	2015-04-26 13:32:22.371684003 -0500
@@ -615,6 +615,7 @@
 	}
 }
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 void do_softirq_own_stack(void)
 {
 	struct thread_info *curtp, *irqtp;
@@ -632,6 +633,7 @@
 	if (irqtp->flags)
 		set_bits(irqtp->flags, &curtp->flags);
 }
+#endif
 
 irq_hw_number_t virq_to_hw(unsigned int virq)
 {
diff -Nur linux-3.18.12.orig/arch/powerpc/kernel/misc_32.S linux-3.18.12/arch/powerpc/kernel/misc_32.S
--- linux-3.18.12.orig/arch/powerpc/kernel/misc_32.S	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/powerpc/kernel/misc_32.S	2015-04-26 13:32:22.371684003 -0500
@@ -40,6 +40,7 @@
  * We store the saved ksp_limit in the unused part
  * of the STACK_FRAME_OVERHEAD
  */
+#ifndef CONFIG_PREEMPT_RT_FULL
 _GLOBAL(call_do_softirq)
 	mflr	r0
 	stw	r0,4(r1)
@@ -56,6 +57,7 @@
 	stw	r10,THREAD+KSP_LIMIT(r2)
 	mtlr	r0
 	blr
+#endif
 
 /*
  * void call_do_irq(struct pt_regs *regs, struct thread_info *irqtp);
diff -Nur linux-3.18.12.orig/arch/powerpc/kernel/misc_64.S linux-3.18.12/arch/powerpc/kernel/misc_64.S
--- linux-3.18.12.orig/arch/powerpc/kernel/misc_64.S	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/powerpc/kernel/misc_64.S	2015-04-26 13:32:22.371684003 -0500
@@ -29,6 +29,7 @@
 
 	.text
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 _GLOBAL(call_do_softirq)
 	mflr	r0
 	std	r0,16(r1)
@@ -39,6 +40,7 @@
 	ld	r0,16(r1)
 	mtlr	r0
 	blr
+#endif
 
 _GLOBAL(call_do_irq)
 	mflr	r0
diff -Nur linux-3.18.12.orig/arch/powerpc/kernel/time.c linux-3.18.12/arch/powerpc/kernel/time.c
--- linux-3.18.12.orig/arch/powerpc/kernel/time.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/powerpc/kernel/time.c	2015-04-26 13:32:22.371684003 -0500
@@ -424,7 +424,7 @@
 EXPORT_SYMBOL(profile_pc);
 #endif
 
-#ifdef CONFIG_IRQ_WORK
+#if defined(CONFIG_IRQ_WORK)
 
 /*
  * 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable...
diff -Nur linux-3.18.12.orig/arch/powerpc/kvm/book3s_hv.c linux-3.18.12/arch/powerpc/kvm/book3s_hv.c
--- linux-3.18.12.orig/arch/powerpc/kvm/book3s_hv.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/powerpc/kvm/book3s_hv.c	2015-04-26 13:32:22.371684003 -0500
@@ -84,11 +84,11 @@
 {
 	int me;
 	int cpu = vcpu->cpu;
-	wait_queue_head_t *wqp;
+	struct swait_head *wqp;
 
 	wqp = kvm_arch_vcpu_wq(vcpu);
-	if (waitqueue_active(wqp)) {
-		wake_up_interruptible(wqp);
+	if (swaitqueue_active(wqp)) {
+		swait_wake_interruptible(wqp);
 		++vcpu->stat.halt_wakeup;
 	}
 
@@ -639,8 +639,8 @@
 		tvcpu->arch.prodded = 1;
 		smp_mb();
 		if (vcpu->arch.ceded) {
-			if (waitqueue_active(&vcpu->wq)) {
-				wake_up_interruptible(&vcpu->wq);
+			if (swaitqueue_active(&vcpu->wq)) {
+				swait_wake_interruptible(&vcpu->wq);
 				vcpu->stat.halt_wakeup++;
 			}
 		}
@@ -1357,7 +1357,7 @@
 
 	INIT_LIST_HEAD(&vcore->runnable_threads);
 	spin_lock_init(&vcore->lock);
-	init_waitqueue_head(&vcore->wq);
+	init_swait_head(&vcore->wq);
 	vcore->preempt_tb = TB_NIL;
 	vcore->lpcr = kvm->arch.lpcr;
 	vcore->first_vcpuid = core * threads_per_subcore;
@@ -1826,13 +1826,13 @@
  */
 static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
 {
-	DEFINE_WAIT(wait);
+	DEFINE_SWAITER(wait);
 
-	prepare_to_wait(&vc->wq, &wait, TASK_INTERRUPTIBLE);
+	swait_prepare(&vc->wq, &wait, TASK_INTERRUPTIBLE);
 	vc->vcore_state = VCORE_SLEEPING;
 	spin_unlock(&vc->lock);
 	schedule();
-	finish_wait(&vc->wq, &wait);
+	swait_finish(&vc->wq, &wait);
 	spin_lock(&vc->lock);
 	vc->vcore_state = VCORE_INACTIVE;
 }
@@ -1873,7 +1873,7 @@
 			kvmppc_create_dtl_entry(vcpu, vc);
 			kvmppc_start_thread(vcpu);
 		} else if (vc->vcore_state == VCORE_SLEEPING) {
-			wake_up(&vc->wq);
+			swait_wake(&vc->wq);
 		}
 
 	}
diff -Nur linux-3.18.12.orig/arch/powerpc/mm/fault.c linux-3.18.12/arch/powerpc/mm/fault.c
--- linux-3.18.12.orig/arch/powerpc/mm/fault.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/powerpc/mm/fault.c	2015-04-26 13:32:22.371684003 -0500
@@ -273,7 +273,7 @@
 	if (!arch_irq_disabled_regs(regs))
 		local_irq_enable();
 
-	if (in_atomic() || mm == NULL) {
+	if (in_atomic() || mm == NULL || pagefault_disabled()) {
 		if (!user_mode(regs)) {
 			rc = SIGSEGV;
 			goto bail;
diff -Nur linux-3.18.12.orig/arch/s390/include/asm/kvm_host.h linux-3.18.12/arch/s390/include/asm/kvm_host.h
--- linux-3.18.12.orig/arch/s390/include/asm/kvm_host.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/s390/include/asm/kvm_host.h	2015-04-26 13:32:22.371684003 -0500
@@ -311,7 +311,7 @@
 	struct list_head list;
 	atomic_t active;
 	struct kvm_s390_float_interrupt *float_int;
-	wait_queue_head_t *wq;
+	struct swait_head *wq;
 	atomic_t *cpuflags;
 	unsigned int action_bits;
 };
diff -Nur linux-3.18.12.orig/arch/s390/kvm/interrupt.c linux-3.18.12/arch/s390/kvm/interrupt.c
--- linux-3.18.12.orig/arch/s390/kvm/interrupt.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/s390/kvm/interrupt.c	2015-04-26 13:32:22.371684003 -0500
@@ -619,13 +619,13 @@
 
 void kvm_s390_vcpu_wakeup(struct kvm_vcpu *vcpu)
 {
-	if (waitqueue_active(&vcpu->wq)) {
+	if (swaitqueue_active(&vcpu->wq)) {
 		/*
 		 * The vcpu gave up the cpu voluntarily, mark it as a good
 		 * yield-candidate.
 		 */
 		vcpu->preempted = true;
-		wake_up_interruptible(&vcpu->wq);
+		swait_wake_interruptible(&vcpu->wq);
 		vcpu->stat.halt_wakeup++;
 	}
 }
@@ -746,7 +746,7 @@
 	spin_lock(&li->lock);
 	list_add(&inti->list, &li->list);
 	atomic_set(&li->active, 1);
-	BUG_ON(waitqueue_active(li->wq));
+	BUG_ON(swaitqueue_active(li->wq));
 	spin_unlock(&li->lock);
 	return 0;
 }
@@ -771,7 +771,7 @@
 	spin_lock(&li->lock);
 	list_add(&inti->list, &li->list);
 	atomic_set(&li->active, 1);
-	BUG_ON(waitqueue_active(li->wq));
+	BUG_ON(swaitqueue_active(li->wq));
 	spin_unlock(&li->lock);
 	return 0;
 }
diff -Nur linux-3.18.12.orig/arch/s390/mm/fault.c linux-3.18.12/arch/s390/mm/fault.c
--- linux-3.18.12.orig/arch/s390/mm/fault.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/s390/mm/fault.c	2015-04-26 13:32:22.371684003 -0500
@@ -435,7 +435,8 @@
 	 * user context.
 	 */
 	fault = VM_FAULT_BADCONTEXT;
-	if (unlikely(!user_space_fault(regs) || in_atomic() || !mm))
+	if (unlikely(!user_space_fault(regs) || !mm ||
+		     tsk->pagefault_disabled))
 		goto out;
 
 	address = trans_exc_code & __FAIL_ADDR_MASK;
diff -Nur linux-3.18.12.orig/arch/score/mm/fault.c linux-3.18.12/arch/score/mm/fault.c
--- linux-3.18.12.orig/arch/score/mm/fault.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/score/mm/fault.c	2015-04-26 13:32:22.371684003 -0500
@@ -73,7 +73,7 @@
 	* If we're in an interrupt or have no user
 	* context, we must not take the fault..
 	*/
-	if (in_atomic() || !mm)
+	if (!mm || pagefault_disabled())
 		goto bad_area_nosemaphore;
 
 	if (user_mode(regs))
diff -Nur linux-3.18.12.orig/arch/sh/kernel/irq.c linux-3.18.12/arch/sh/kernel/irq.c
--- linux-3.18.12.orig/arch/sh/kernel/irq.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/sh/kernel/irq.c	2015-04-26 13:32:22.371684003 -0500
@@ -149,6 +149,7 @@
 	hardirq_ctx[cpu] = NULL;
 }
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 void do_softirq_own_stack(void)
 {
 	struct thread_info *curctx;
@@ -176,6 +177,7 @@
 		  "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr"
 	);
 }
+#endif
 #else
 static inline void handle_one_irq(unsigned int irq)
 {
diff -Nur linux-3.18.12.orig/arch/sh/mm/fault.c linux-3.18.12/arch/sh/mm/fault.c
--- linux-3.18.12.orig/arch/sh/mm/fault.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/sh/mm/fault.c	2015-04-26 13:32:22.371684003 -0500
@@ -440,7 +440,7 @@
 	 * If we're in an interrupt, have no user context or are running
 	 * in an atomic region then we must not take the fault:
 	 */
-	if (unlikely(in_atomic() || !mm)) {
+	if (unlikely(!mm || pagefault_disabled())) {
 		bad_area_nosemaphore(regs, error_code, address);
 		return;
 	}
diff -Nur linux-3.18.12.orig/arch/sparc/Kconfig linux-3.18.12/arch/sparc/Kconfig
--- linux-3.18.12.orig/arch/sparc/Kconfig	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/sparc/Kconfig	2015-04-26 13:32:22.371684003 -0500
@@ -182,12 +182,10 @@
 source kernel/Kconfig.hz
 
 config RWSEM_GENERIC_SPINLOCK
-	bool
-	default y if SPARC32
+	def_bool PREEMPT_RT_FULL
 
 config RWSEM_XCHGADD_ALGORITHM
-	bool
-	default y if SPARC64
+	def_bool !RWSEM_GENERIC_SPINLOCK && !PREEMPT_RT_FULL
 
 config GENERIC_HWEIGHT
 	bool
@@ -528,6 +526,10 @@
 
 source "fs/Kconfig.binfmt"
 
+config EARLY_PRINTK
+	bool
+	default y
+
 config COMPAT
 	bool
 	depends on SPARC64
diff -Nur linux-3.18.12.orig/arch/sparc/kernel/irq_64.c linux-3.18.12/arch/sparc/kernel/irq_64.c
--- linux-3.18.12.orig/arch/sparc/kernel/irq_64.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/sparc/kernel/irq_64.c	2015-04-26 13:32:22.375684003 -0500
@@ -849,6 +849,7 @@
 	set_irq_regs(old_regs);
 }
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 void do_softirq_own_stack(void)
 {
 	void *orig_sp, *sp = softirq_stack[smp_processor_id()];
@@ -863,6 +864,7 @@
 	__asm__ __volatile__("mov %0, %%sp"
 			     : : "r" (orig_sp));
 }
+#endif
 
 #ifdef CONFIG_HOTPLUG_CPU
 void fixup_irqs(void)
diff -Nur linux-3.18.12.orig/arch/sparc/kernel/setup_32.c linux-3.18.12/arch/sparc/kernel/setup_32.c
--- linux-3.18.12.orig/arch/sparc/kernel/setup_32.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/sparc/kernel/setup_32.c	2015-04-26 13:32:22.375684003 -0500
@@ -309,6 +309,7 @@
 
 	boot_flags_init(*cmdline_p);
 
+	early_console = &prom_early_console;
 	register_console(&prom_early_console);
 
 	printk("ARCH: ");
diff -Nur linux-3.18.12.orig/arch/sparc/kernel/setup_64.c linux-3.18.12/arch/sparc/kernel/setup_64.c
--- linux-3.18.12.orig/arch/sparc/kernel/setup_64.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/sparc/kernel/setup_64.c	2015-04-26 13:32:22.375684003 -0500
@@ -563,6 +563,12 @@
 		pause_patch();
 }
 
+static inline void register_prom_console(void)
+{
+	early_console = &prom_early_console;
+	register_console(&prom_early_console);
+}
+
 void __init setup_arch(char **cmdline_p)
 {
 	/* Initialize PROM console and command line. */
@@ -574,7 +580,7 @@
 #ifdef CONFIG_EARLYFB
 	if (btext_find_display())
 #endif
-		register_console(&prom_early_console);
+		register_prom_console();
 
 	if (tlb_type == hypervisor)
 		printk("ARCH: SUN4V\n");
diff -Nur linux-3.18.12.orig/arch/sparc/mm/fault_32.c linux-3.18.12/arch/sparc/mm/fault_32.c
--- linux-3.18.12.orig/arch/sparc/mm/fault_32.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/sparc/mm/fault_32.c	2015-04-26 13:32:22.375684003 -0500
@@ -196,7 +196,7 @@
 	 * If we're in an interrupt or have no user
 	 * context, we must not take the fault..
 	 */
-	if (in_atomic() || !mm)
+	if (!mm || pagefault_disabled())
 		goto no_context;
 
 	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
diff -Nur linux-3.18.12.orig/arch/sparc/mm/fault_64.c linux-3.18.12/arch/sparc/mm/fault_64.c
--- linux-3.18.12.orig/arch/sparc/mm/fault_64.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/sparc/mm/fault_64.c	2015-04-26 13:32:22.375684003 -0500
@@ -330,7 +330,7 @@
 	 * If we're in an interrupt or have no user
 	 * context, we must not take the fault..
 	 */
-	if (in_atomic() || !mm)
+	if (!mm || pagefault_disabled())
 		goto intr_or_no_mm;
 
 	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
diff -Nur linux-3.18.12.orig/arch/tile/mm/fault.c linux-3.18.12/arch/tile/mm/fault.c
--- linux-3.18.12.orig/arch/tile/mm/fault.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/tile/mm/fault.c	2015-04-26 13:32:22.375684003 -0500
@@ -357,7 +357,7 @@
 	 * If we're in an interrupt, have no user context or are running in an
 	 * atomic region then we must not take the fault.
 	 */
-	if (in_atomic() || !mm) {
+	if (!mm || pagefault_disabled()) {
 		vma = NULL;  /* happy compiler */
 		goto bad_area_nosemaphore;
 	}
diff -Nur linux-3.18.12.orig/arch/um/kernel/trap.c linux-3.18.12/arch/um/kernel/trap.c
--- linux-3.18.12.orig/arch/um/kernel/trap.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/um/kernel/trap.c	2015-04-26 13:32:22.375684003 -0500
@@ -38,7 +38,7 @@
 	 * If the fault was during atomic operation, don't take the fault, just
 	 * fail.
 	 */
-	if (in_atomic())
+	if (pagefault_disabled())
 		goto out_nosemaphore;
 
 	if (is_user)
diff -Nur linux-3.18.12.orig/arch/x86/crypto/aesni-intel_glue.c linux-3.18.12/arch/x86/crypto/aesni-intel_glue.c
--- linux-3.18.12.orig/arch/x86/crypto/aesni-intel_glue.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/crypto/aesni-intel_glue.c	2015-04-26 13:32:22.375684003 -0500
@@ -381,14 +381,14 @@
 	err = blkcipher_walk_virt(desc, &walk);
 	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 
-	kernel_fpu_begin();
 	while ((nbytes = walk.nbytes)) {
+		kernel_fpu_begin();
 		aesni_ecb_enc(ctx, walk.dst.virt.addr, walk.src.virt.addr,
-			      nbytes & AES_BLOCK_MASK);
+				nbytes & AES_BLOCK_MASK);
+		kernel_fpu_end();
 		nbytes &= AES_BLOCK_SIZE - 1;
 		err = blkcipher_walk_done(desc, &walk, nbytes);
 	}
-	kernel_fpu_end();
 
 	return err;
 }
@@ -405,14 +405,14 @@
 	err = blkcipher_walk_virt(desc, &walk);
 	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 
-	kernel_fpu_begin();
 	while ((nbytes = walk.nbytes)) {
+		kernel_fpu_begin();
 		aesni_ecb_dec(ctx, walk.dst.virt.addr, walk.src.virt.addr,
 			      nbytes & AES_BLOCK_MASK);
+		kernel_fpu_end();
 		nbytes &= AES_BLOCK_SIZE - 1;
 		err = blkcipher_walk_done(desc, &walk, nbytes);
 	}
-	kernel_fpu_end();
 
 	return err;
 }
@@ -429,14 +429,14 @@
 	err = blkcipher_walk_virt(desc, &walk);
 	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 
-	kernel_fpu_begin();
 	while ((nbytes = walk.nbytes)) {
+		kernel_fpu_begin();
 		aesni_cbc_enc(ctx, walk.dst.virt.addr, walk.src.virt.addr,
 			      nbytes & AES_BLOCK_MASK, walk.iv);
+		kernel_fpu_end();
 		nbytes &= AES_BLOCK_SIZE - 1;
 		err = blkcipher_walk_done(desc, &walk, nbytes);
 	}
-	kernel_fpu_end();
 
 	return err;
 }
@@ -453,14 +453,14 @@
 	err = blkcipher_walk_virt(desc, &walk);
 	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 
-	kernel_fpu_begin();
 	while ((nbytes = walk.nbytes)) {
+		kernel_fpu_begin();
 		aesni_cbc_dec(ctx, walk.dst.virt.addr, walk.src.virt.addr,
 			      nbytes & AES_BLOCK_MASK, walk.iv);
+		kernel_fpu_end();
 		nbytes &= AES_BLOCK_SIZE - 1;
 		err = blkcipher_walk_done(desc, &walk, nbytes);
 	}
-	kernel_fpu_end();
 
 	return err;
 }
@@ -512,18 +512,20 @@
 	err = blkcipher_walk_virt_block(desc, &walk, AES_BLOCK_SIZE);
 	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 
-	kernel_fpu_begin();
 	while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) {
+		kernel_fpu_begin();
 		aesni_ctr_enc_tfm(ctx, walk.dst.virt.addr, walk.src.virt.addr,
 				  nbytes & AES_BLOCK_MASK, walk.iv);
+		kernel_fpu_end();
 		nbytes &= AES_BLOCK_SIZE - 1;
 		err = blkcipher_walk_done(desc, &walk, nbytes);
 	}
 	if (walk.nbytes) {
+		kernel_fpu_begin();
 		ctr_crypt_final(ctx, &walk);
+		kernel_fpu_end();
 		err = blkcipher_walk_done(desc, &walk, 0);
 	}
-	kernel_fpu_end();
 
 	return err;
 }
diff -Nur linux-3.18.12.orig/arch/x86/crypto/cast5_avx_glue.c linux-3.18.12/arch/x86/crypto/cast5_avx_glue.c
--- linux-3.18.12.orig/arch/x86/crypto/cast5_avx_glue.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/crypto/cast5_avx_glue.c	2015-04-26 13:32:22.375684003 -0500
@@ -60,7 +60,7 @@
 static int ecb_crypt(struct blkcipher_desc *desc, struct blkcipher_walk *walk,
 		     bool enc)
 {
-	bool fpu_enabled = false;
+	bool fpu_enabled;
 	struct cast5_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
 	const unsigned int bsize = CAST5_BLOCK_SIZE;
 	unsigned int nbytes;
@@ -76,7 +76,7 @@
 		u8 *wsrc = walk->src.virt.addr;
 		u8 *wdst = walk->dst.virt.addr;
 
-		fpu_enabled = cast5_fpu_begin(fpu_enabled, nbytes);
+		fpu_enabled = cast5_fpu_begin(false, nbytes);
 
 		/* Process multi-block batch */
 		if (nbytes >= bsize * CAST5_PARALLEL_BLOCKS) {
@@ -104,10 +104,9 @@
 		} while (nbytes >= bsize);
 
 done:
+		cast5_fpu_end(fpu_enabled);
 		err = blkcipher_walk_done(desc, walk, nbytes);
 	}
-
-	cast5_fpu_end(fpu_enabled);
 	return err;
 }
 
@@ -228,7 +227,7 @@
 static int cbc_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
 		       struct scatterlist *src, unsigned int nbytes)
 {
-	bool fpu_enabled = false;
+	bool fpu_enabled;
 	struct blkcipher_walk walk;
 	int err;
 
@@ -237,12 +236,11 @@
 	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 
 	while ((nbytes = walk.nbytes)) {
-		fpu_enabled = cast5_fpu_begin(fpu_enabled, nbytes);
+		fpu_enabled = cast5_fpu_begin(false, nbytes);
 		nbytes = __cbc_decrypt(desc, &walk);
+		cast5_fpu_end(fpu_enabled);
 		err = blkcipher_walk_done(desc, &walk, nbytes);
 	}
-
-	cast5_fpu_end(fpu_enabled);
 	return err;
 }
 
@@ -312,7 +310,7 @@
 static int ctr_crypt(struct blkcipher_desc *desc, struct scatterlist *dst,
 		     struct scatterlist *src, unsigned int nbytes)
 {
-	bool fpu_enabled = false;
+	bool fpu_enabled;
 	struct blkcipher_walk walk;
 	int err;
 
@@ -321,13 +319,12 @@
 	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
 
 	while ((nbytes = walk.nbytes) >= CAST5_BLOCK_SIZE) {
-		fpu_enabled = cast5_fpu_begin(fpu_enabled, nbytes);
+		fpu_enabled = cast5_fpu_begin(false, nbytes);
 		nbytes = __ctr_crypt(desc, &walk);
+		cast5_fpu_end(fpu_enabled);
 		err = blkcipher_walk_done(desc, &walk, nbytes);
 	}
 
-	cast5_fpu_end(fpu_enabled);
-
 	if (walk.nbytes) {
 		ctr_crypt_final(desc, &walk);
 		err = blkcipher_walk_done(desc, &walk, 0);
diff -Nur linux-3.18.12.orig/arch/x86/crypto/glue_helper.c linux-3.18.12/arch/x86/crypto/glue_helper.c
--- linux-3.18.12.orig/arch/x86/crypto/glue_helper.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/crypto/glue_helper.c	2015-04-26 13:32:22.375684003 -0500
@@ -39,7 +39,7 @@
 	void *ctx = crypto_blkcipher_ctx(desc->tfm);
 	const unsigned int bsize = 128 / 8;
 	unsigned int nbytes, i, func_bytes;
-	bool fpu_enabled = false;
+	bool fpu_enabled;
 	int err;
 
 	err = blkcipher_walk_virt(desc, walk);
@@ -49,7 +49,7 @@
 		u8 *wdst = walk->dst.virt.addr;
 
 		fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
-					     desc, fpu_enabled, nbytes);
+					     desc, false, nbytes);
 
 		for (i = 0; i < gctx->num_funcs; i++) {
 			func_bytes = bsize * gctx->funcs[i].num_blocks;
@@ -71,10 +71,10 @@
 		}
 
 done:
+		glue_fpu_end(fpu_enabled);
 		err = blkcipher_walk_done(desc, walk, nbytes);
 	}
 
-	glue_fpu_end(fpu_enabled);
 	return err;
 }
 
@@ -194,7 +194,7 @@
 			    struct scatterlist *src, unsigned int nbytes)
 {
 	const unsigned int bsize = 128 / 8;
-	bool fpu_enabled = false;
+	bool fpu_enabled;
 	struct blkcipher_walk walk;
 	int err;
 
@@ -203,12 +203,12 @@
 
 	while ((nbytes = walk.nbytes)) {
 		fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
-					     desc, fpu_enabled, nbytes);
+					     desc, false, nbytes);
 		nbytes = __glue_cbc_decrypt_128bit(gctx, desc, &walk);
+		glue_fpu_end(fpu_enabled);
 		err = blkcipher_walk_done(desc, &walk, nbytes);
 	}
 
-	glue_fpu_end(fpu_enabled);
 	return err;
 }
 EXPORT_SYMBOL_GPL(glue_cbc_decrypt_128bit);
@@ -278,7 +278,7 @@
 			  struct scatterlist *src, unsigned int nbytes)
 {
 	const unsigned int bsize = 128 / 8;
-	bool fpu_enabled = false;
+	bool fpu_enabled;
 	struct blkcipher_walk walk;
 	int err;
 
@@ -287,13 +287,12 @@
 
 	while ((nbytes = walk.nbytes) >= bsize) {
 		fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
-					     desc, fpu_enabled, nbytes);
+					     desc, false, nbytes);
 		nbytes = __glue_ctr_crypt_128bit(gctx, desc, &walk);
+		glue_fpu_end(fpu_enabled);
 		err = blkcipher_walk_done(desc, &walk, nbytes);
 	}
 
-	glue_fpu_end(fpu_enabled);
-
 	if (walk.nbytes) {
 		glue_ctr_crypt_final_128bit(
 			gctx->funcs[gctx->num_funcs - 1].fn_u.ctr, desc, &walk);
@@ -348,7 +347,7 @@
 			  void *tweak_ctx, void *crypt_ctx)
 {
 	const unsigned int bsize = 128 / 8;
-	bool fpu_enabled = false;
+	bool fpu_enabled;
 	struct blkcipher_walk walk;
 	int err;
 
@@ -361,21 +360,21 @@
 
 	/* set minimum length to bsize, for tweak_fn */
 	fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
-				     desc, fpu_enabled,
+				     desc, false,
 				     nbytes < bsize ? bsize : nbytes);
-
 	/* calculate first value of T */
 	tweak_fn(tweak_ctx, walk.iv, walk.iv);
+	glue_fpu_end(fpu_enabled);
 
 	while (nbytes) {
+		fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
+				desc, false, nbytes);
 		nbytes = __glue_xts_crypt_128bit(gctx, crypt_ctx, desc, &walk);
 
+		glue_fpu_end(fpu_enabled);
 		err = blkcipher_walk_done(desc, &walk, nbytes);
 		nbytes = walk.nbytes;
 	}
-
-	glue_fpu_end(fpu_enabled);
-
 	return err;
 }
 EXPORT_SYMBOL_GPL(glue_xts_crypt_128bit);
diff -Nur linux-3.18.12.orig/arch/x86/include/asm/preempt.h linux-3.18.12/arch/x86/include/asm/preempt.h
--- linux-3.18.12.orig/arch/x86/include/asm/preempt.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/include/asm/preempt.h	2015-04-26 13:32:22.375684003 -0500
@@ -85,17 +85,33 @@
  * a decrement which hits zero means we have no preempt_count and should
  * reschedule.
  */
-static __always_inline bool __preempt_count_dec_and_test(void)
+static __always_inline bool ____preempt_count_dec_and_test(void)
 {
 	GEN_UNARY_RMWcc("decl", __preempt_count, __percpu_arg(0), "e");
 }
 
+static __always_inline bool __preempt_count_dec_and_test(void)
+{
+	if (____preempt_count_dec_and_test())
+		return true;
+#ifdef CONFIG_PREEMPT_LAZY
+	return test_thread_flag(TIF_NEED_RESCHED_LAZY);
+#else
+	return false;
+#endif
+}
+
 /*
  * Returns true when we need to resched and can (barring IRQ state).
  */
 static __always_inline bool should_resched(void)
 {
+#ifdef CONFIG_PREEMPT_LAZY
+	return unlikely(!raw_cpu_read_4(__preempt_count) || \
+			test_thread_flag(TIF_NEED_RESCHED_LAZY));
+#else
 	return unlikely(!raw_cpu_read_4(__preempt_count));
+#endif
 }
 
 #ifdef CONFIG_PREEMPT
diff -Nur linux-3.18.12.orig/arch/x86/include/asm/signal.h linux-3.18.12/arch/x86/include/asm/signal.h
--- linux-3.18.12.orig/arch/x86/include/asm/signal.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/include/asm/signal.h	2015-04-26 13:32:22.375684003 -0500
@@ -23,6 +23,19 @@
 	unsigned long sig[_NSIG_WORDS];
 } sigset_t;
 
+/*
+ * Because some traps use the IST stack, we must keep preemption
+ * disabled while calling do_trap(), but do_trap() may call
+ * force_sig_info() which will grab the signal spin_locks for the
+ * task, which in PREEMPT_RT_FULL are mutexes.  By defining
+ * ARCH_RT_DELAYS_SIGNAL_SEND the force_sig_info() will set
+ * TIF_NOTIFY_RESUME and set up the signal to be sent on exit of the
+ * trap.
+ */
+#if defined(CONFIG_PREEMPT_RT_FULL) && defined(CONFIG_X86_64)
+#define ARCH_RT_DELAYS_SIGNAL_SEND
+#endif
+
 #ifndef CONFIG_COMPAT
 typedef sigset_t compat_sigset_t;
 #endif
diff -Nur linux-3.18.12.orig/arch/x86/include/asm/stackprotector.h linux-3.18.12/arch/x86/include/asm/stackprotector.h
--- linux-3.18.12.orig/arch/x86/include/asm/stackprotector.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/include/asm/stackprotector.h	2015-04-26 13:32:22.375684003 -0500
@@ -57,7 +57,7 @@
  */
 static __always_inline void boot_init_stack_canary(void)
 {
-	u64 canary;
+	u64 uninitialized_var(canary);
 	u64 tsc;
 
 #ifdef CONFIG_X86_64
@@ -68,8 +68,16 @@
 	 * of randomness. The TSC only matters for very early init,
 	 * there it already has some randomness on most systems. Later
 	 * on during the bootup the random pool has true entropy too.
+	 *
+	 * For preempt-rt we need to weaken the randomness a bit, as
+	 * we can't call into the random generator from atomic context
+	 * due to locking constraints. We just leave canary
+	 * uninitialized and use the TSC based randomness on top of
+	 * it.
 	 */
+#ifndef CONFIG_PREEMPT_RT_FULL
 	get_random_bytes(&canary, sizeof(canary));
+#endif
 	tsc = __native_read_tsc();
 	canary += tsc + (tsc << 32UL);
 
diff -Nur linux-3.18.12.orig/arch/x86/include/asm/thread_info.h linux-3.18.12/arch/x86/include/asm/thread_info.h
--- linux-3.18.12.orig/arch/x86/include/asm/thread_info.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/include/asm/thread_info.h	2015-04-26 13:32:22.375684003 -0500
@@ -30,6 +30,8 @@
 	__u32			status;		/* thread synchronous flags */
 	__u32			cpu;		/* current CPU */
 	int			saved_preempt_count;
+	int			preempt_lazy_count;	/* 0 => lazy preemptable
+							   <0 => BUG */
 	mm_segment_t		addr_limit;
 	struct restart_block    restart_block;
 	void __user		*sysenter_return;
@@ -75,6 +77,7 @@
 #define TIF_SYSCALL_EMU		6	/* syscall emulation active */
 #define TIF_SYSCALL_AUDIT	7	/* syscall auditing active */
 #define TIF_SECCOMP		8	/* secure computing */
+#define TIF_NEED_RESCHED_LAZY	9	/* lazy rescheduling necessary */
 #define TIF_MCE_NOTIFY		10	/* notify userspace of an MCE */
 #define TIF_USER_RETURN_NOTIFY	11	/* notify kernel of userspace return */
 #define TIF_UPROBE		12	/* breakpointed or singlestepping */
@@ -100,6 +103,7 @@
 #define _TIF_SYSCALL_EMU	(1 << TIF_SYSCALL_EMU)
 #define _TIF_SYSCALL_AUDIT	(1 << TIF_SYSCALL_AUDIT)
 #define _TIF_SECCOMP		(1 << TIF_SECCOMP)
+#define _TIF_NEED_RESCHED_LAZY	(1 << TIF_NEED_RESCHED_LAZY)
 #define _TIF_MCE_NOTIFY		(1 << TIF_MCE_NOTIFY)
 #define _TIF_USER_RETURN_NOTIFY	(1 << TIF_USER_RETURN_NOTIFY)
 #define _TIF_UPROBE		(1 << TIF_UPROBE)
@@ -150,6 +154,8 @@
 #define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY)
 #define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW)
 
+#define _TIF_NEED_RESCHED_MASK (_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY)
+
 #define STACK_WARN		(THREAD_SIZE/8)
 #define KERNEL_STACK_OFFSET	(5*(BITS_PER_LONG/8))
 
diff -Nur linux-3.18.12.orig/arch/x86/include/asm/uv/uv_bau.h linux-3.18.12/arch/x86/include/asm/uv/uv_bau.h
--- linux-3.18.12.orig/arch/x86/include/asm/uv/uv_bau.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/include/asm/uv/uv_bau.h	2015-04-26 13:32:22.375684003 -0500
@@ -615,9 +615,9 @@
 	cycles_t		send_message;
 	cycles_t		period_end;
 	cycles_t		period_time;
-	spinlock_t		uvhub_lock;
-	spinlock_t		queue_lock;
-	spinlock_t		disable_lock;
+	raw_spinlock_t		uvhub_lock;
+	raw_spinlock_t		queue_lock;
+	raw_spinlock_t		disable_lock;
 	/* tunables */
 	int			max_concurr;
 	int			max_concurr_const;
@@ -776,15 +776,15 @@
  * to be lowered below the current 'v'.  atomic_add_unless can only stop
  * on equal.
  */
-static inline int atomic_inc_unless_ge(spinlock_t *lock, atomic_t *v, int u)
+static inline int atomic_inc_unless_ge(raw_spinlock_t *lock, atomic_t *v, int u)
 {
-	spin_lock(lock);
+	raw_spin_lock(lock);
 	if (atomic_read(v) >= u) {
-		spin_unlock(lock);
+		raw_spin_unlock(lock);
 		return 0;
 	}
 	atomic_inc(v);
-	spin_unlock(lock);
+	raw_spin_unlock(lock);
 	return 1;
 }
 
diff -Nur linux-3.18.12.orig/arch/x86/include/asm/uv/uv_hub.h linux-3.18.12/arch/x86/include/asm/uv/uv_hub.h
--- linux-3.18.12.orig/arch/x86/include/asm/uv/uv_hub.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/include/asm/uv/uv_hub.h	2015-04-26 13:32:22.375684003 -0500
@@ -492,7 +492,7 @@
 	unsigned short	nr_online_cpus;
 	unsigned short	pnode;
 	short		memory_nid;
-	spinlock_t	nmi_lock;	/* obsolete, see uv_hub_nmi */
+	raw_spinlock_t	nmi_lock;	/* obsolete, see uv_hub_nmi */
 	unsigned long	nmi_count;	/* obsolete, see uv_hub_nmi */
 };
 extern struct uv_blade_info *uv_blade_info;
diff -Nur linux-3.18.12.orig/arch/x86/Kconfig linux-3.18.12/arch/x86/Kconfig
--- linux-3.18.12.orig/arch/x86/Kconfig	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/Kconfig	2015-04-26 13:32:22.375684003 -0500
@@ -21,6 +21,7 @@
 ### Arch settings
 config X86
 	def_bool y
+	select HAVE_PREEMPT_LAZY
 	select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
 	select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
 	select ARCH_HAS_FAST_MULTIPLIER
@@ -197,8 +198,11 @@
 	def_bool y
 	depends on ISA_DMA_API
 
+config RWSEM_GENERIC_SPINLOCK
+	def_bool PREEMPT_RT_FULL
+
 config RWSEM_XCHGADD_ALGORITHM
-	def_bool y
+	def_bool !RWSEM_GENERIC_SPINLOCK && !PREEMPT_RT_FULL
 
 config GENERIC_CALIBRATE_DELAY
 	def_bool y
@@ -811,7 +815,7 @@
 config MAXSMP
 	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
 	depends on X86_64 && SMP && DEBUG_KERNEL
-	select CPUMASK_OFFSTACK
+	select CPUMASK_OFFSTACK if !PREEMPT_RT_FULL
 	---help---
 	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
 	  If unsure, say N.
diff -Nur linux-3.18.12.orig/arch/x86/kernel/apic/io_apic.c linux-3.18.12/arch/x86/kernel/apic/io_apic.c
--- linux-3.18.12.orig/arch/x86/kernel/apic/io_apic.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/kernel/apic/io_apic.c	2015-04-26 13:32:22.379684003 -0500
@@ -2494,7 +2494,8 @@
 static inline bool ioapic_irqd_mask(struct irq_data *data, struct irq_cfg *cfg)
 {
 	/* If we are moving the irq we need to mask it */
-	if (unlikely(irqd_is_setaffinity_pending(data))) {
+	if (unlikely(irqd_is_setaffinity_pending(data) &&
+		     !irqd_irq_inprogress(data))) {
 		mask_ioapic(cfg);
 		return true;
 	}
diff -Nur linux-3.18.12.orig/arch/x86/kernel/apic/x2apic_uv_x.c linux-3.18.12/arch/x86/kernel/apic/x2apic_uv_x.c
--- linux-3.18.12.orig/arch/x86/kernel/apic/x2apic_uv_x.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/kernel/apic/x2apic_uv_x.c	2015-04-26 13:32:22.379684003 -0500
@@ -918,7 +918,7 @@
 			uv_blade_info[blade].pnode = pnode;
 			uv_blade_info[blade].nr_possible_cpus = 0;
 			uv_blade_info[blade].nr_online_cpus = 0;
-			spin_lock_init(&uv_blade_info[blade].nmi_lock);
+			raw_spin_lock_init(&uv_blade_info[blade].nmi_lock);
 			min_pnode = min(pnode, min_pnode);
 			max_pnode = max(pnode, max_pnode);
 			blade++;
diff -Nur linux-3.18.12.orig/arch/x86/kernel/asm-offsets.c linux-3.18.12/arch/x86/kernel/asm-offsets.c
--- linux-3.18.12.orig/arch/x86/kernel/asm-offsets.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/kernel/asm-offsets.c	2015-04-26 13:32:22.379684003 -0500
@@ -32,6 +32,7 @@
 	OFFSET(TI_flags, thread_info, flags);
 	OFFSET(TI_status, thread_info, status);
 	OFFSET(TI_addr_limit, thread_info, addr_limit);
+	OFFSET(TI_preempt_lazy_count, thread_info, preempt_lazy_count);
 
 	BLANK();
 	OFFSET(crypto_tfm_ctx_offset, crypto_tfm, __crt_ctx);
@@ -71,4 +72,5 @@
 
 	BLANK();
 	DEFINE(PTREGS_SIZE, sizeof(struct pt_regs));
+	DEFINE(_PREEMPT_ENABLED, PREEMPT_ENABLED);
 }
diff -Nur linux-3.18.12.orig/arch/x86/kernel/cpu/mcheck/mce.c linux-3.18.12/arch/x86/kernel/cpu/mcheck/mce.c
--- linux-3.18.12.orig/arch/x86/kernel/cpu/mcheck/mce.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/kernel/cpu/mcheck/mce.c	2015-04-26 13:32:22.379684003 -0500
@@ -41,6 +41,8 @@
 #include <linux/debugfs.h>
 #include <linux/irq_work.h>
 #include <linux/export.h>
+#include <linux/jiffies.h>
+#include <linux/work-simple.h>
 
 #include <asm/processor.h>
 #include <asm/mce.h>
@@ -1266,7 +1268,7 @@
 static unsigned long check_interval = 5 * 60; /* 5 minutes */
 
 static DEFINE_PER_CPU(unsigned long, mce_next_interval); /* in jiffies */
-static DEFINE_PER_CPU(struct timer_list, mce_timer);
+static DEFINE_PER_CPU(struct hrtimer, mce_timer);
 
 static unsigned long mce_adjust_timer_default(unsigned long interval)
 {
@@ -1283,14 +1285,11 @@
 	return test_and_clear_bit(0, v);
 }
 
-static void mce_timer_fn(unsigned long data)
+static enum hrtimer_restart mce_timer_fn(struct hrtimer *timer)
 {
-	struct timer_list *t = this_cpu_ptr(&mce_timer);
 	unsigned long iv;
 	int notify;
 
-	WARN_ON(smp_processor_id() != data);
-
 	if (mce_available(this_cpu_ptr(&cpu_info))) {
 		machine_check_poll(MCP_TIMESTAMP,
 				this_cpu_ptr(&mce_poll_banks));
@@ -1313,9 +1312,11 @@
 	__this_cpu_write(mce_next_interval, iv);
 	/* Might have become 0 after CMCI storm subsided */
 	if (iv) {
-		t->expires = jiffies + iv;
-		add_timer_on(t, smp_processor_id());
+		hrtimer_forward_now(timer, ns_to_ktime(
+					jiffies_to_usecs(iv) * 1000ULL));
+		return HRTIMER_RESTART;
 	}
+	return HRTIMER_NORESTART;
 }
 
 /*
@@ -1323,28 +1324,37 @@
  */
 void mce_timer_kick(unsigned long interval)
 {
-	struct timer_list *t = this_cpu_ptr(&mce_timer);
-	unsigned long when = jiffies + interval;
+	struct hrtimer *t = this_cpu_ptr(&mce_timer);
 	unsigned long iv = __this_cpu_read(mce_next_interval);
 
-	if (timer_pending(t)) {
-		if (time_before(when, t->expires))
-			mod_timer_pinned(t, when);
+	if (hrtimer_active(t)) {
+		s64 exp;
+		s64 intv_us;
+
+		intv_us = jiffies_to_usecs(interval);
+		exp = ktime_to_us(hrtimer_expires_remaining(t));
+		if (intv_us < exp) {
+			hrtimer_cancel(t);
+			hrtimer_start_range_ns(t,
+					ns_to_ktime(intv_us * 1000),
+					0, HRTIMER_MODE_REL_PINNED);
+		}
 	} else {
-		t->expires = round_jiffies(when);
-		add_timer_on(t, smp_processor_id());
+		hrtimer_start_range_ns(t,
+			ns_to_ktime(jiffies_to_usecs(interval) * 1000ULL),
+				0, HRTIMER_MODE_REL_PINNED);
 	}
 	if (interval < iv)
 		__this_cpu_write(mce_next_interval, interval);
 }
 
-/* Must not be called in IRQ context where del_timer_sync() can deadlock */
+/* Must not be called in IRQ context where hrtimer_cancel() can deadlock */
 static void mce_timer_delete_all(void)
 {
 	int cpu;
 
 	for_each_online_cpu(cpu)
-		del_timer_sync(&per_cpu(mce_timer, cpu));
+		hrtimer_cancel(&per_cpu(mce_timer, cpu));
 }
 
 static void mce_do_trigger(struct work_struct *work)
@@ -1354,6 +1364,56 @@
 
 static DECLARE_WORK(mce_trigger_work, mce_do_trigger);
 
+static void __mce_notify_work(struct swork_event *event)
+{
+	/* Not more than two messages every minute */
+	static DEFINE_RATELIMIT_STATE(ratelimit, 60*HZ, 2);
+
+	/* wake processes polling /dev/mcelog */
+	wake_up_interruptible(&mce_chrdev_wait);
+
+	/*
+	 * There is no risk of missing notifications because
+	 * work_pending is always cleared before the function is
+	 * executed.
+	 */
+	if (mce_helper[0] && !work_pending(&mce_trigger_work))
+		schedule_work(&mce_trigger_work);
+
+	if (__ratelimit(&ratelimit))
+		pr_info(HW_ERR "Machine check events logged\n");
+}
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+static bool notify_work_ready __read_mostly;
+static struct swork_event notify_work;
+
+static int mce_notify_work_init(void)
+{
+	int err;
+
+	err = swork_get();
+	if (err)
+		return err;
+
+	INIT_SWORK(&notify_work, __mce_notify_work);
+	notify_work_ready = true;
+	return 0;
+}
+
+static void mce_notify_work(void)
+{
+	if (notify_work_ready)
+		swork_queue(&notify_work);
+}
+#else
+static void mce_notify_work(void)
+{
+	__mce_notify_work(NULL);
+}
+static inline int mce_notify_work_init(void) { return 0; }
+#endif
+
 /*
  * Notify the user(s) about new machine check events.
  * Can be called from interrupt context, but not from machine check/NMI
@@ -1361,19 +1421,8 @@
  */
 int mce_notify_irq(void)
 {
-	/* Not more than two messages every minute */
-	static DEFINE_RATELIMIT_STATE(ratelimit, 60*HZ, 2);
-
 	if (test_and_clear_bit(0, &mce_need_notify)) {
-		/* wake processes polling /dev/mcelog */
-		wake_up_interruptible(&mce_chrdev_wait);
-
-		if (mce_helper[0])
-			schedule_work(&mce_trigger_work);
-
-		if (__ratelimit(&ratelimit))
-			pr_info(HW_ERR "Machine check events logged\n");
-
+		mce_notify_work();
 		return 1;
 	}
 	return 0;
@@ -1644,7 +1693,7 @@
 	}
 }
 
-static void mce_start_timer(unsigned int cpu, struct timer_list *t)
+static void mce_start_timer(unsigned int cpu, struct hrtimer *t)
 {
 	unsigned long iv = check_interval * HZ;
 
@@ -1653,16 +1702,17 @@
 
 	per_cpu(mce_next_interval, cpu) = iv;
 
-	t->expires = round_jiffies(jiffies + iv);
-	add_timer_on(t, cpu);
+	hrtimer_start_range_ns(t, ns_to_ktime(jiffies_to_usecs(iv) * 1000ULL),
+			0, HRTIMER_MODE_REL_PINNED);
 }
 
 static void __mcheck_cpu_init_timer(void)
 {
-	struct timer_list *t = this_cpu_ptr(&mce_timer);
+	struct hrtimer *t = this_cpu_ptr(&mce_timer);
 	unsigned int cpu = smp_processor_id();
 
-	setup_timer(t, mce_timer_fn, cpu);
+	hrtimer_init(t, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	t->function = mce_timer_fn;
 	mce_start_timer(cpu, t);
 }
 
@@ -2339,6 +2389,8 @@
 	if (!mce_available(raw_cpu_ptr(&cpu_info)))
 		return;
 
+	hrtimer_cancel(this_cpu_ptr(&mce_timer));
+
 	if (!(action & CPU_TASKS_FROZEN))
 		cmci_clear();
 	for (i = 0; i < mca_cfg.banks; i++) {
@@ -2365,6 +2417,7 @@
 		if (b->init)
 			wrmsrl(MSR_IA32_MCx_CTL(i), b->ctl);
 	}
+	__mcheck_cpu_init_timer();
 }
 
 /* Get notified when a cpu comes on/off. Be hotplug friendly. */
@@ -2372,7 +2425,6 @@
 mce_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
 {
 	unsigned int cpu = (unsigned long)hcpu;
-	struct timer_list *t = &per_cpu(mce_timer, cpu);
 
 	switch (action & ~CPU_TASKS_FROZEN) {
 	case CPU_ONLINE:
@@ -2392,11 +2444,9 @@
 		break;
 	case CPU_DOWN_PREPARE:
 		smp_call_function_single(cpu, mce_disable_cpu, &action, 1);
-		del_timer_sync(t);
 		break;
 	case CPU_DOWN_FAILED:
 		smp_call_function_single(cpu, mce_reenable_cpu, &action, 1);
-		mce_start_timer(cpu, t);
 		break;
 	}
 
@@ -2435,6 +2485,10 @@
 		goto err_out;
 	}
 
+	err = mce_notify_work_init();
+	if (err)
+		goto err_out;
+
 	if (!zalloc_cpumask_var(&mce_device_initialized, GFP_KERNEL)) {
 		err = -ENOMEM;
 		goto err_out;
diff -Nur linux-3.18.12.orig/arch/x86/kernel/entry_32.S linux-3.18.12/arch/x86/kernel/entry_32.S
--- linux-3.18.12.orig/arch/x86/kernel/entry_32.S	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/kernel/entry_32.S	2015-04-26 13:32:22.379684003 -0500
@@ -359,8 +359,24 @@
 ENTRY(resume_kernel)
 	DISABLE_INTERRUPTS(CLBR_ANY)
 need_resched:
+	# preempt count == 0 + NEED_RS set?
 	cmpl $0,PER_CPU_VAR(__preempt_count)
+#ifndef CONFIG_PREEMPT_LAZY
 	jnz restore_all
+#else
+	jz test_int_off
+
+	# atleast preempt count == 0 ?
+	cmpl $_PREEMPT_ENABLED,PER_CPU_VAR(__preempt_count)
+	jne restore_all
+
+	cmpl $0,TI_preempt_lazy_count(%ebp)	# non-zero preempt_lazy_count ?
+	jnz restore_all
+
+	testl $_TIF_NEED_RESCHED_LAZY, TI_flags(%ebp)
+	jz restore_all
+test_int_off:
+#endif
 	testl $X86_EFLAGS_IF,PT_EFLAGS(%esp)	# interrupts off (exception path) ?
 	jz restore_all
 	call preempt_schedule_irq
@@ -591,7 +607,7 @@
 	ALIGN
 	RING0_PTREGS_FRAME		# can't unwind into user space anyway
 work_pending:
-	testb $_TIF_NEED_RESCHED, %cl
+	testl $_TIF_NEED_RESCHED_MASK, %ecx
 	jz work_notifysig
 work_resched:
 	call schedule
@@ -604,7 +620,7 @@
 	andl $_TIF_WORK_MASK, %ecx	# is there any work to be done other
 					# than syscall tracing?
 	jz restore_all
-	testb $_TIF_NEED_RESCHED, %cl
+	testl $_TIF_NEED_RESCHED_MASK, %ecx
 	jnz work_resched
 
 work_notifysig:				# deal with pending signals and
diff -Nur linux-3.18.12.orig/arch/x86/kernel/entry_64.S linux-3.18.12/arch/x86/kernel/entry_64.S
--- linux-3.18.12.orig/arch/x86/kernel/entry_64.S	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/kernel/entry_64.S	2015-04-26 13:32:22.379684003 -0500
@@ -454,8 +454,8 @@
 	/* Handle reschedules */
 	/* edx:	work, edi: workmask */
 sysret_careful:
-	bt $TIF_NEED_RESCHED,%edx
-	jnc sysret_signal
+	testl $_TIF_NEED_RESCHED_MASK,%edx
+	jz sysret_signal
 	TRACE_IRQS_ON
 	ENABLE_INTERRUPTS(CLBR_NONE)
 	pushq_cfi %rdi
@@ -554,8 +554,8 @@
 	/* First do a reschedule test. */
 	/* edx:	work, edi: workmask */
 int_careful:
-	bt $TIF_NEED_RESCHED,%edx
-	jnc  int_very_careful
+	testl $_TIF_NEED_RESCHED_MASK,%edx
+	jz  int_very_careful
 	TRACE_IRQS_ON
 	ENABLE_INTERRUPTS(CLBR_NONE)
 	pushq_cfi %rdi
@@ -870,8 +870,8 @@
 	/* edi: workmask, edx: work */
 retint_careful:
 	CFI_RESTORE_STATE
-	bt    $TIF_NEED_RESCHED,%edx
-	jnc   retint_signal
+	testl $_TIF_NEED_RESCHED_MASK,%edx
+	jz   retint_signal
 	TRACE_IRQS_ON
 	ENABLE_INTERRUPTS(CLBR_NONE)
 	pushq_cfi %rdi
@@ -903,7 +903,22 @@
 	/* rcx:	 threadinfo. interrupts off. */
 ENTRY(retint_kernel)
 	cmpl $0,PER_CPU_VAR(__preempt_count)
+#ifndef CONFIG_PREEMPT_LAZY
 	jnz  retint_restore_args
+#else
+	jz  check_int_off
+
+	# atleast preempt count == 0 ?
+	cmpl $_PREEMPT_ENABLED,PER_CPU_VAR(__preempt_count)
+	jnz retint_restore_args
+
+	cmpl $0, TI_preempt_lazy_count(%rcx)
+	jnz retint_restore_args
+
+	bt $TIF_NEED_RESCHED_LAZY,TI_flags(%rcx)
+	jnc  retint_restore_args
+check_int_off:
+#endif
 	bt   $9,EFLAGS-ARGOFFSET(%rsp)	/* interrupts off? */
 	jnc  retint_restore_args
 	call preempt_schedule_irq
@@ -1119,6 +1134,7 @@
 	jmp  2b
 	.previous
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 /* Call softirq on interrupt stack. Interrupts are off. */
 ENTRY(do_softirq_own_stack)
 	CFI_STARTPROC
@@ -1138,6 +1154,7 @@
 	ret
 	CFI_ENDPROC
 END(do_softirq_own_stack)
+#endif
 
 #ifdef CONFIG_XEN
 idtentry xen_hypervisor_callback xen_do_hypervisor_callback has_error_code=0
@@ -1302,7 +1319,7 @@
 	movq %rsp,%rdi			/* &pt_regs */
 	call sync_regs
 	movq %rax,%rsp			/* switch stack for scheduling */
-	testl $_TIF_NEED_RESCHED,%ebx
+	testl $_TIF_NEED_RESCHED_MASK,%ebx
 	jnz paranoid_schedule
 	movl %ebx,%edx			/* arg3: thread flags */
 	TRACE_IRQS_ON
diff -Nur linux-3.18.12.orig/arch/x86/kernel/irq_32.c linux-3.18.12/arch/x86/kernel/irq_32.c
--- linux-3.18.12.orig/arch/x86/kernel/irq_32.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/kernel/irq_32.c	2015-04-26 13:32:22.379684003 -0500
@@ -142,6 +142,7 @@
 	       cpu, per_cpu(hardirq_stack, cpu),  per_cpu(softirq_stack, cpu));
 }
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 void do_softirq_own_stack(void)
 {
 	struct thread_info *curstk;
@@ -160,6 +161,7 @@
 
 	call_on_stack(__do_softirq, isp);
 }
+#endif
 
 bool handle_irq(unsigned irq, struct pt_regs *regs)
 {
diff -Nur linux-3.18.12.orig/arch/x86/kernel/process_32.c linux-3.18.12/arch/x86/kernel/process_32.c
--- linux-3.18.12.orig/arch/x86/kernel/process_32.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/kernel/process_32.c	2015-04-26 13:32:22.379684003 -0500
@@ -35,6 +35,7 @@
 #include <linux/uaccess.h>
 #include <linux/io.h>
 #include <linux/kdebug.h>
+#include <linux/highmem.h>
 
 #include <asm/pgtable.h>
 #include <asm/ldt.h>
@@ -214,6 +215,35 @@
 }
 EXPORT_SYMBOL_GPL(start_thread);
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+static void switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p)
+{
+	int i;
+
+	/*
+	 * Clear @prev's kmap_atomic mappings
+	 */
+	for (i = 0; i < prev_p->kmap_idx; i++) {
+		int idx = i + KM_TYPE_NR * smp_processor_id();
+		pte_t *ptep = kmap_pte - idx;
+
+		kpte_clear_flush(ptep, __fix_to_virt(FIX_KMAP_BEGIN + idx));
+	}
+	/*
+	 * Restore @next_p's kmap_atomic mappings
+	 */
+	for (i = 0; i < next_p->kmap_idx; i++) {
+		int idx = i + KM_TYPE_NR * smp_processor_id();
+
+		if (!pte_none(next_p->kmap_pte[i]))
+			set_pte(kmap_pte - idx, next_p->kmap_pte[i]);
+	}
+}
+#else
+static inline void
+switch_kmaps(struct task_struct *prev_p, struct task_struct *next_p) { }
+#endif
+
 
 /*
  *	switch_to(x,y) should switch tasks from x to y.
@@ -301,6 +331,8 @@
 		     task_thread_info(next_p)->flags & _TIF_WORK_CTXSW_NEXT))
 		__switch_to_xtra(prev_p, next_p, tss);
 
+	switch_kmaps(prev_p, next_p);
+
 	/*
 	 * Leave lazy mode, flushing any hypercalls made here.
 	 * This must be done before restoring TLS segments so
diff -Nur linux-3.18.12.orig/arch/x86/kernel/signal.c linux-3.18.12/arch/x86/kernel/signal.c
--- linux-3.18.12.orig/arch/x86/kernel/signal.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/kernel/signal.c	2015-04-26 13:32:22.379684003 -0500
@@ -746,6 +746,14 @@
 		mce_notify_process();
 #endif /* CONFIG_X86_64 && CONFIG_X86_MCE */
 
+#ifdef ARCH_RT_DELAYS_SIGNAL_SEND
+	if (unlikely(current->forced_info.si_signo)) {
+		struct task_struct *t = current;
+		force_sig_info(t->forced_info.si_signo,	&t->forced_info, t);
+		t->forced_info.si_signo = 0;
+	}
+#endif
+
 	if (thread_info_flags & _TIF_UPROBE)
 		uprobe_notify_resume(regs);
 
diff -Nur linux-3.18.12.orig/arch/x86/kernel/traps.c linux-3.18.12/arch/x86/kernel/traps.c
--- linux-3.18.12.orig/arch/x86/kernel/traps.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/kernel/traps.c	2015-04-26 13:32:22.379684003 -0500
@@ -87,9 +87,21 @@
 		local_irq_enable();
 }
 
-static inline void preempt_conditional_sti(struct pt_regs *regs)
+static inline void conditional_sti_ist(struct pt_regs *regs)
 {
+#ifdef CONFIG_X86_64
+	/*
+	 * X86_64 uses a per CPU stack on the IST for certain traps
+	 * like int3. The task can not be preempted when using one
+	 * of these stacks, thus preemption must be disabled, otherwise
+	 * the stack can be corrupted if the task is scheduled out,
+	 * and another task comes in and uses this stack.
+	 *
+	 * On x86_32 the task keeps its own stack and it is OK if the
+	 * task schedules out.
+	 */
 	preempt_count_inc();
+#endif
 	if (regs->flags & X86_EFLAGS_IF)
 		local_irq_enable();
 }
@@ -100,11 +112,13 @@
 		local_irq_disable();
 }
 
-static inline void preempt_conditional_cli(struct pt_regs *regs)
+static inline void conditional_cli_ist(struct pt_regs *regs)
 {
 	if (regs->flags & X86_EFLAGS_IF)
 		local_irq_disable();
+#ifdef CONFIG_X86_64
 	preempt_count_dec();
+#endif
 }
 
 static nokprobe_inline int
@@ -372,9 +386,9 @@
 	 * as we may switch to the interrupt stack.
 	 */
 	debug_stack_usage_inc();
-	preempt_conditional_sti(regs);
+	conditional_sti_ist(regs);
 	do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, error_code, NULL);
-	preempt_conditional_cli(regs);
+	conditional_cli_ist(regs);
 	debug_stack_usage_dec();
 exit:
 	exception_exit(prev_state);
@@ -517,12 +531,12 @@
 	debug_stack_usage_inc();
 
 	/* It's safe to allow irq's after DR6 has been saved */
-	preempt_conditional_sti(regs);
+	conditional_sti_ist(regs);
 
 	if (regs->flags & X86_VM_MASK) {
 		handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code,
 					X86_TRAP_DB);
-		preempt_conditional_cli(regs);
+		conditional_cli_ist(regs);
 		debug_stack_usage_dec();
 		goto exit;
 	}
@@ -542,7 +556,7 @@
 	si_code = get_si_code(tsk->thread.debugreg6);
 	if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS) || user_icebp)
 		send_sigtrap(tsk, regs, error_code, si_code);
-	preempt_conditional_cli(regs);
+	conditional_cli_ist(regs);
 	debug_stack_usage_dec();
 
 exit:
diff -Nur linux-3.18.12.orig/arch/x86/kvm/lapic.c linux-3.18.12/arch/x86/kvm/lapic.c
--- linux-3.18.12.orig/arch/x86/kvm/lapic.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/kvm/lapic.c	2015-04-26 13:32:22.379684003 -0500
@@ -1034,8 +1034,38 @@
 				   apic->divide_count);
 }
 
+
+static enum hrtimer_restart apic_timer_fn(struct hrtimer *data);
+
+static void apic_timer_expired(struct hrtimer *data)
+{
+	int ret, i = 0;
+	enum hrtimer_restart r;
+	struct kvm_timer *ktimer = container_of(data, struct kvm_timer, timer);
+
+	r = apic_timer_fn(data);
+
+	if (r == HRTIMER_RESTART) {
+		do {
+			ret = hrtimer_start_expires(data, HRTIMER_MODE_ABS);
+			if (ret == -ETIME)
+				hrtimer_add_expires_ns(&ktimer->timer,
+							ktimer->period);
+			i++;
+		} while (ret == -ETIME && i < 10);
+
+		if (ret == -ETIME) {
+			printk_once(KERN_ERR "%s: failed to reprogram timer\n",
+			       __func__);
+			WARN_ON_ONCE(1);
+		}
+	}
+}
+
+
 static void start_apic_timer(struct kvm_lapic *apic)
 {
+	int ret;
 	ktime_t now;
 	atomic_set(&apic->lapic_timer.pending, 0);
 
@@ -1065,9 +1095,11 @@
 			}
 		}
 
-		hrtimer_start(&apic->lapic_timer.timer,
+		ret = hrtimer_start(&apic->lapic_timer.timer,
 			      ktime_add_ns(now, apic->lapic_timer.period),
 			      HRTIMER_MODE_ABS);
+		if (ret == -ETIME)
+			apic_timer_expired(&apic->lapic_timer.timer);
 
 		apic_debug("%s: bus cycle is %" PRId64 "ns, now 0x%016"
 			   PRIx64 ", "
@@ -1097,8 +1129,10 @@
 			ns = (tscdeadline - guest_tsc) * 1000000ULL;
 			do_div(ns, this_tsc_khz);
 		}
-		hrtimer_start(&apic->lapic_timer.timer,
+		ret = hrtimer_start(&apic->lapic_timer.timer,
 			ktime_add_ns(now, ns), HRTIMER_MODE_ABS);
+		if (ret == -ETIME)
+			apic_timer_expired(&apic->lapic_timer.timer);
 
 		local_irq_restore(flags);
 	}
@@ -1539,7 +1573,7 @@
 	struct kvm_timer *ktimer = container_of(data, struct kvm_timer, timer);
 	struct kvm_lapic *apic = container_of(ktimer, struct kvm_lapic, lapic_timer);
 	struct kvm_vcpu *vcpu = apic->vcpu;
-	wait_queue_head_t *q = &vcpu->wq;
+	struct swait_head *q = &vcpu->wq;
 
 	/*
 	 * There is a race window between reading and incrementing, but we do
@@ -1553,8 +1587,8 @@
 		kvm_make_request(KVM_REQ_PENDING_TIMER, vcpu);
 	}
 
-	if (waitqueue_active(q))
-		wake_up_interruptible(q);
+	if (swaitqueue_active(q))
+		swait_wake_interruptible(q);
 
 	if (lapic_is_periodic(apic)) {
 		hrtimer_add_expires_ns(&ktimer->timer, ktimer->period);
@@ -1587,6 +1621,7 @@
 	hrtimer_init(&apic->lapic_timer.timer, CLOCK_MONOTONIC,
 		     HRTIMER_MODE_ABS);
 	apic->lapic_timer.timer.function = apic_timer_fn;
+	apic->lapic_timer.timer.irqsafe = 1;
 
 	/*
 	 * APIC is created enabled. This will prevent kvm_lapic_set_base from
@@ -1707,7 +1742,8 @@
 
 	timer = &vcpu->arch.apic->lapic_timer.timer;
 	if (hrtimer_cancel(timer))
-		hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
+		if (hrtimer_start_expires(timer, HRTIMER_MODE_ABS) == -ETIME)
+			apic_timer_expired(timer);
 }
 
 /*
diff -Nur linux-3.18.12.orig/arch/x86/kvm/x86.c linux-3.18.12/arch/x86/kvm/x86.c
--- linux-3.18.12.orig/arch/x86/kvm/x86.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/kvm/x86.c	2015-04-26 13:32:22.383684003 -0500
@@ -5772,6 +5772,13 @@
 		goto out;
 	}
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+	if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC)) {
+		printk(KERN_ERR "RT requires X86_FEATURE_CONSTANT_TSC\n");
+		return -EOPNOTSUPP;
+	}
+#endif
+
 	r = kvm_mmu_module_init();
 	if (r)
 		goto out_free_percpu;
diff -Nur linux-3.18.12.orig/arch/x86/mm/fault.c linux-3.18.12/arch/x86/mm/fault.c
--- linux-3.18.12.orig/arch/x86/mm/fault.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/mm/fault.c	2015-04-26 13:32:22.383684003 -0500
@@ -1128,7 +1128,7 @@
 	 * If we're in an interrupt, have no user context or are running
 	 * in an atomic region then we must not take the fault:
 	 */
-	if (unlikely(in_atomic() || !mm)) {
+	if (unlikely(!mm || pagefault_disabled())) {
 		bad_area_nosemaphore(regs, error_code, address);
 		return;
 	}
diff -Nur linux-3.18.12.orig/arch/x86/mm/highmem_32.c linux-3.18.12/arch/x86/mm/highmem_32.c
--- linux-3.18.12.orig/arch/x86/mm/highmem_32.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/mm/highmem_32.c	2015-04-26 13:32:22.383684003 -0500
@@ -32,6 +32,7 @@
  */
 void *kmap_atomic_prot(struct page *page, pgprot_t prot)
 {
+	pte_t pte = mk_pte(page, prot);
 	unsigned long vaddr;
 	int idx, type;
 
@@ -45,7 +46,10 @@
 	idx = type + KM_TYPE_NR*smp_processor_id();
 	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
 	BUG_ON(!pte_none(*(kmap_pte-idx)));
-	set_pte(kmap_pte-idx, mk_pte(page, prot));
+#ifdef CONFIG_PREEMPT_RT_FULL
+	current->kmap_pte[type] = pte;
+#endif
+	set_pte(kmap_pte-idx, pte);
 	arch_flush_lazy_mmu_mode();
 
 	return (void *)vaddr;
@@ -88,6 +92,9 @@
 		 * is a bad idea also, in case the page changes cacheability
 		 * attributes or becomes a protected page in a hypervisor.
 		 */
+#ifdef CONFIG_PREEMPT_RT_FULL
+		current->kmap_pte[type] = __pte(0);
+#endif
 		kpte_clear_flush(kmap_pte-idx, vaddr);
 		kmap_atomic_idx_pop();
 		arch_flush_lazy_mmu_mode();
diff -Nur linux-3.18.12.orig/arch/x86/mm/iomap_32.c linux-3.18.12/arch/x86/mm/iomap_32.c
--- linux-3.18.12.orig/arch/x86/mm/iomap_32.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/mm/iomap_32.c	2015-04-26 13:32:22.383684003 -0500
@@ -56,6 +56,7 @@
 
 void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
 {
+	pte_t pte = pfn_pte(pfn, prot);
 	unsigned long vaddr;
 	int idx, type;
 
@@ -64,7 +65,12 @@
 	type = kmap_atomic_idx_push();
 	idx = type + KM_TYPE_NR * smp_processor_id();
 	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-	set_pte(kmap_pte - idx, pfn_pte(pfn, prot));
+	WARN_ON(!pte_none(*(kmap_pte - idx)));
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+	current->kmap_pte[type] = pte;
+#endif
+	set_pte(kmap_pte - idx, pte);
 	arch_flush_lazy_mmu_mode();
 
 	return (void *)vaddr;
@@ -110,6 +116,9 @@
 		 * is a bad idea also, in case the page changes cacheability
 		 * attributes or becomes a protected page in a hypervisor.
 		 */
+#ifdef CONFIG_PREEMPT_RT_FULL
+		current->kmap_pte[type] = __pte(0);
+#endif
 		kpte_clear_flush(kmap_pte-idx, vaddr);
 		kmap_atomic_idx_pop();
 	}
diff -Nur linux-3.18.12.orig/arch/x86/platform/uv/tlb_uv.c linux-3.18.12/arch/x86/platform/uv/tlb_uv.c
--- linux-3.18.12.orig/arch/x86/platform/uv/tlb_uv.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/platform/uv/tlb_uv.c	2015-04-26 13:32:22.383684003 -0500
@@ -714,9 +714,9 @@
 
 		quiesce_local_uvhub(hmaster);
 
-		spin_lock(&hmaster->queue_lock);
+		raw_spin_lock(&hmaster->queue_lock);
 		reset_with_ipi(&bau_desc->distribution, bcp);
-		spin_unlock(&hmaster->queue_lock);
+		raw_spin_unlock(&hmaster->queue_lock);
 
 		end_uvhub_quiesce(hmaster);
 
@@ -736,9 +736,9 @@
 
 		quiesce_local_uvhub(hmaster);
 
-		spin_lock(&hmaster->queue_lock);
+		raw_spin_lock(&hmaster->queue_lock);
 		reset_with_ipi(&bau_desc->distribution, bcp);
-		spin_unlock(&hmaster->queue_lock);
+		raw_spin_unlock(&hmaster->queue_lock);
 
 		end_uvhub_quiesce(hmaster);
 
@@ -759,7 +759,7 @@
 	cycles_t tm1;
 
 	hmaster = bcp->uvhub_master;
-	spin_lock(&hmaster->disable_lock);
+	raw_spin_lock(&hmaster->disable_lock);
 	if (!bcp->baudisabled) {
 		stat->s_bau_disabled++;
 		tm1 = get_cycles();
@@ -772,7 +772,7 @@
 			}
 		}
 	}
-	spin_unlock(&hmaster->disable_lock);
+	raw_spin_unlock(&hmaster->disable_lock);
 }
 
 static void count_max_concurr(int stat, struct bau_control *bcp,
@@ -835,7 +835,7 @@
  */
 static void uv1_throttle(struct bau_control *hmaster, struct ptc_stats *stat)
 {
-	spinlock_t *lock = &hmaster->uvhub_lock;
+	raw_spinlock_t *lock = &hmaster->uvhub_lock;
 	atomic_t *v;
 
 	v = &hmaster->active_descriptor_count;
@@ -968,7 +968,7 @@
 	struct bau_control *hmaster;
 
 	hmaster = bcp->uvhub_master;
-	spin_lock(&hmaster->disable_lock);
+	raw_spin_lock(&hmaster->disable_lock);
 	if (bcp->baudisabled && (get_cycles() >= bcp->set_bau_on_time)) {
 		stat->s_bau_reenabled++;
 		for_each_present_cpu(tcpu) {
@@ -980,10 +980,10 @@
 				tbcp->period_giveups = 0;
 			}
 		}
-		spin_unlock(&hmaster->disable_lock);
+		raw_spin_unlock(&hmaster->disable_lock);
 		return 0;
 	}
-	spin_unlock(&hmaster->disable_lock);
+	raw_spin_unlock(&hmaster->disable_lock);
 	return -1;
 }
 
@@ -1899,9 +1899,9 @@
 		bcp->cong_reps			= congested_reps;
 		bcp->disabled_period =		sec_2_cycles(disabled_period);
 		bcp->giveup_limit =		giveup_limit;
-		spin_lock_init(&bcp->queue_lock);
-		spin_lock_init(&bcp->uvhub_lock);
-		spin_lock_init(&bcp->disable_lock);
+		raw_spin_lock_init(&bcp->queue_lock);
+		raw_spin_lock_init(&bcp->uvhub_lock);
+		raw_spin_lock_init(&bcp->disable_lock);
 	}
 }
 
diff -Nur linux-3.18.12.orig/arch/x86/platform/uv/uv_time.c linux-3.18.12/arch/x86/platform/uv/uv_time.c
--- linux-3.18.12.orig/arch/x86/platform/uv/uv_time.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/x86/platform/uv/uv_time.c	2015-04-26 13:32:22.383684003 -0500
@@ -58,7 +58,7 @@
 
 /* There is one of these allocated per node */
 struct uv_rtc_timer_head {
-	spinlock_t	lock;
+	raw_spinlock_t	lock;
 	/* next cpu waiting for timer, local node relative: */
 	int		next_cpu;
 	/* number of cpus on this node: */
@@ -178,7 +178,7 @@
 				uv_rtc_deallocate_timers();
 				return -ENOMEM;
 			}
-			spin_lock_init(&head->lock);
+			raw_spin_lock_init(&head->lock);
 			head->ncpus = uv_blade_nr_possible_cpus(bid);
 			head->next_cpu = -1;
 			blade_info[bid] = head;
@@ -232,7 +232,7 @@
 	unsigned long flags;
 	int next_cpu;
 
-	spin_lock_irqsave(&head->lock, flags);
+	raw_spin_lock_irqsave(&head->lock, flags);
 
 	next_cpu = head->next_cpu;
 	*t = expires;
@@ -244,12 +244,12 @@
 		if (uv_setup_intr(cpu, expires)) {
 			*t = ULLONG_MAX;
 			uv_rtc_find_next_timer(head, pnode);
-			spin_unlock_irqrestore(&head->lock, flags);
+			raw_spin_unlock_irqrestore(&head->lock, flags);
 			return -ETIME;
 		}
 	}
 
-	spin_unlock_irqrestore(&head->lock, flags);
+	raw_spin_unlock_irqrestore(&head->lock, flags);
 	return 0;
 }
 
@@ -268,7 +268,7 @@
 	unsigned long flags;
 	int rc = 0;
 
-	spin_lock_irqsave(&head->lock, flags);
+	raw_spin_lock_irqsave(&head->lock, flags);
 
 	if ((head->next_cpu == bcpu && uv_read_rtc(NULL) >= *t) || force)
 		rc = 1;
@@ -280,7 +280,7 @@
 			uv_rtc_find_next_timer(head, pnode);
 	}
 
-	spin_unlock_irqrestore(&head->lock, flags);
+	raw_spin_unlock_irqrestore(&head->lock, flags);
 
 	return rc;
 }
@@ -300,13 +300,18 @@
 static cycle_t uv_read_rtc(struct clocksource *cs)
 {
 	unsigned long offset;
+	cycle_t cycles;
 
+	preempt_disable();
 	if (uv_get_min_hub_revision_id() == 1)
 		offset = 0;
 	else
 		offset = (uv_blade_processor_id() * L1_CACHE_BYTES) % PAGE_SIZE;
 
-	return (cycle_t)uv_read_local_mmr(UVH_RTC | offset);
+	cycles = (cycle_t)uv_read_local_mmr(UVH_RTC | offset);
+	preempt_enable();
+
+	return cycles;
 }
 
 /*
diff -Nur linux-3.18.12.orig/arch/xtensa/mm/fault.c linux-3.18.12/arch/xtensa/mm/fault.c
--- linux-3.18.12.orig/arch/xtensa/mm/fault.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/arch/xtensa/mm/fault.c	2015-04-26 13:32:22.383684003 -0500
@@ -57,7 +57,7 @@
 	/* If we're in an interrupt or have no user
 	 * context, we must not take the fault..
 	 */
-	if (in_atomic() || !mm) {
+	if (!mm || pagefault_disabled()) {
 		bad_page_fault(regs, address, SIGSEGV);
 		return;
 	}
diff -Nur linux-3.18.12.orig/block/blk-core.c linux-3.18.12/block/blk-core.c
--- linux-3.18.12.orig/block/blk-core.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/block/blk-core.c	2015-04-26 13:32:22.383684003 -0500
@@ -100,6 +100,9 @@
 
 	INIT_LIST_HEAD(&rq->queuelist);
 	INIT_LIST_HEAD(&rq->timeout_list);
+#if CONFIG_PREEMPT_RT_FULL
+	INIT_WORK(&rq->work, __blk_mq_complete_request_remote_work);
+#endif
 	rq->cpu = -1;
 	rq->q = q;
 	rq->__sector = (sector_t) -1;
@@ -194,7 +197,7 @@
  **/
 void blk_start_queue(struct request_queue *q)
 {
-	WARN_ON(!irqs_disabled());
+	WARN_ON_NONRT(!irqs_disabled());
 
 	queue_flag_clear(QUEUE_FLAG_STOPPED, q);
 	__blk_run_queue(q);
@@ -627,7 +630,7 @@
 	q->bypass_depth = 1;
 	__set_bit(QUEUE_FLAG_BYPASS, &q->queue_flags);
 
-	init_waitqueue_head(&q->mq_freeze_wq);
+	init_swait_head(&q->mq_freeze_wq);
 
 	if (blkcg_init_queue(q))
 		goto fail_bdi;
@@ -3037,7 +3040,7 @@
 		blk_run_queue_async(q);
 	else
 		__blk_run_queue(q);
-	spin_unlock(q->queue_lock);
+	spin_unlock_irq(q->queue_lock);
 }
 
 static void flush_plug_callbacks(struct blk_plug *plug, bool from_schedule)
@@ -3085,7 +3088,6 @@
 void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
 {
 	struct request_queue *q;
-	unsigned long flags;
 	struct request *rq;
 	LIST_HEAD(list);
 	unsigned int depth;
@@ -3105,11 +3107,6 @@
 	q = NULL;
 	depth = 0;
 
-	/*
-	 * Save and disable interrupts here, to avoid doing it for every
-	 * queue lock we have to take.
-	 */
-	local_irq_save(flags);
 	while (!list_empty(&list)) {
 		rq = list_entry_rq(list.next);
 		list_del_init(&rq->queuelist);
@@ -3122,7 +3119,7 @@
 				queue_unplugged(q, depth, from_schedule);
 			q = rq->q;
 			depth = 0;
-			spin_lock(q->queue_lock);
+			spin_lock_irq(q->queue_lock);
 		}
 
 		/*
@@ -3149,8 +3146,6 @@
 	 */
 	if (q)
 		queue_unplugged(q, depth, from_schedule);
-
-	local_irq_restore(flags);
 }
 
 void blk_finish_plug(struct blk_plug *plug)
diff -Nur linux-3.18.12.orig/block/blk-ioc.c linux-3.18.12/block/blk-ioc.c
--- linux-3.18.12.orig/block/blk-ioc.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/block/blk-ioc.c	2015-04-26 13:32:22.383684003 -0500
@@ -7,6 +7,7 @@
 #include <linux/bio.h>
 #include <linux/blkdev.h>
 #include <linux/slab.h>
+#include <linux/delay.h>
 
 #include "blk.h"
 
@@ -109,7 +110,7 @@
 			spin_unlock(q->queue_lock);
 		} else {
 			spin_unlock_irqrestore(&ioc->lock, flags);
-			cpu_relax();
+			cpu_chill();
 			spin_lock_irqsave_nested(&ioc->lock, flags, 1);
 		}
 	}
@@ -187,7 +188,7 @@
 			spin_unlock(icq->q->queue_lock);
 		} else {
 			spin_unlock_irqrestore(&ioc->lock, flags);
-			cpu_relax();
+			cpu_chill();
 			goto retry;
 		}
 	}
diff -Nur linux-3.18.12.orig/block/blk-iopoll.c linux-3.18.12/block/blk-iopoll.c
--- linux-3.18.12.orig/block/blk-iopoll.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/block/blk-iopoll.c	2015-04-26 13:32:22.383684003 -0500
@@ -35,6 +35,7 @@
 	list_add_tail(&iop->list, this_cpu_ptr(&blk_cpu_iopoll));
 	__raise_softirq_irqoff(BLOCK_IOPOLL_SOFTIRQ);
 	local_irq_restore(flags);
+	preempt_check_resched_rt();
 }
 EXPORT_SYMBOL(blk_iopoll_sched);
 
@@ -132,6 +133,7 @@
 		__raise_softirq_irqoff(BLOCK_IOPOLL_SOFTIRQ);
 
 	local_irq_enable();
+	preempt_check_resched_rt();
 }
 
 /**
@@ -201,6 +203,7 @@
 				 this_cpu_ptr(&blk_cpu_iopoll));
 		__raise_softirq_irqoff(BLOCK_IOPOLL_SOFTIRQ);
 		local_irq_enable();
+		preempt_check_resched_rt();
 	}
 
 	return NOTIFY_OK;
diff -Nur linux-3.18.12.orig/block/blk-mq.c linux-3.18.12/block/blk-mq.c
--- linux-3.18.12.orig/block/blk-mq.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/block/blk-mq.c	2015-04-26 13:32:22.383684003 -0500
@@ -85,7 +85,7 @@
 		if (percpu_ref_tryget_live(&q->mq_usage_counter))
 			return 0;
 
-		ret = wait_event_interruptible(q->mq_freeze_wq,
+		ret = swait_event_interruptible(q->mq_freeze_wq,
 				!q->mq_freeze_depth || blk_queue_dying(q));
 		if (blk_queue_dying(q))
 			return -ENODEV;
@@ -104,7 +104,7 @@
 	struct request_queue *q =
 		container_of(ref, struct request_queue, mq_usage_counter);
 
-	wake_up_all(&q->mq_freeze_wq);
+	swait_wake_all(&q->mq_freeze_wq);
 }
 
 static void blk_mq_freeze_queue_start(struct request_queue *q)
@@ -123,7 +123,7 @@
 
 static void blk_mq_freeze_queue_wait(struct request_queue *q)
 {
-	wait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->mq_usage_counter));
+	swait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->mq_usage_counter));
 }
 
 /*
@@ -146,7 +146,7 @@
 	spin_unlock_irq(q->queue_lock);
 	if (wake) {
 		percpu_ref_reinit(&q->mq_usage_counter);
-		wake_up_all(&q->mq_freeze_wq);
+		swait_wake_all(&q->mq_freeze_wq);
 	}
 }
 
@@ -194,6 +194,9 @@
 	rq->resid_len = 0;
 	rq->sense = NULL;
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+	INIT_WORK(&rq->work, __blk_mq_complete_request_remote_work);
+#endif
 	INIT_LIST_HEAD(&rq->timeout_list);
 	rq->timeout = 0;
 
@@ -313,6 +316,17 @@
 }
 EXPORT_SYMBOL(blk_mq_end_request);
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+
+void __blk_mq_complete_request_remote_work(struct work_struct *work)
+{
+	struct request *rq = container_of(work, struct request, work);
+
+	rq->q->softirq_done_fn(rq);
+}
+
+#else
+
 static void __blk_mq_complete_request_remote(void *data)
 {
 	struct request *rq = data;
@@ -320,6 +334,8 @@
 	rq->q->softirq_done_fn(rq);
 }
 
+#endif
+
 static void blk_mq_ipi_complete_request(struct request *rq)
 {
 	struct blk_mq_ctx *ctx = rq->mq_ctx;
@@ -331,19 +347,23 @@
 		return;
 	}
 
-	cpu = get_cpu();
+	cpu = get_cpu_light();
 	if (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags))
 		shared = cpus_share_cache(cpu, ctx->cpu);
 
 	if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) {
+#ifdef CONFIG_PREEMPT_RT_FULL
+		schedule_work_on(ctx->cpu, &rq->work);
+#else
 		rq->csd.func = __blk_mq_complete_request_remote;
 		rq->csd.info = rq;
 		rq->csd.flags = 0;
 		smp_call_function_single_async(ctx->cpu, &rq->csd);
+#endif
 	} else {
 		rq->q->softirq_done_fn(rq);
 	}
-	put_cpu();
+	put_cpu_light();
 }
 
 void __blk_mq_complete_request(struct request *rq)
@@ -814,9 +834,9 @@
 		    test_bit(BLK_MQ_S_STOPPED, &hctx->state))
 			continue;
 
-		preempt_disable();
+		migrate_disable();
 		blk_mq_run_hw_queue(hctx, async);
-		preempt_enable();
+		migrate_enable();
 	}
 }
 EXPORT_SYMBOL(blk_mq_run_queues);
@@ -843,9 +863,9 @@
 {
 	clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
 
-	preempt_disable();
+	migrate_disable();
 	blk_mq_run_hw_queue(hctx, false);
-	preempt_enable();
+	migrate_enable();
 }
 EXPORT_SYMBOL(blk_mq_start_hw_queue);
 
@@ -870,9 +890,9 @@
 			continue;
 
 		clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
-		preempt_disable();
+		migrate_disable();
 		blk_mq_run_hw_queue(hctx, async);
-		preempt_enable();
+		migrate_enable();
 	}
 }
 EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues);
@@ -1494,7 +1514,7 @@
 {
 	struct blk_mq_hw_ctx *hctx = data;
 
-	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN)
+	if (action == CPU_POST_DEAD)
 		return blk_mq_hctx_cpu_offline(hctx, cpu);
 	else if (action == CPU_ONLINE || action == CPU_ONLINE_FROZEN)
 		return blk_mq_hctx_cpu_online(hctx, cpu);
diff -Nur linux-3.18.12.orig/block/blk-mq-cpu.c linux-3.18.12/block/blk-mq-cpu.c
--- linux-3.18.12.orig/block/blk-mq-cpu.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/block/blk-mq-cpu.c	2015-04-26 13:32:22.383684003 -0500
@@ -16,7 +16,7 @@
 #include "blk-mq.h"
 
 static LIST_HEAD(blk_mq_cpu_notify_list);
-static DEFINE_RAW_SPINLOCK(blk_mq_cpu_notify_lock);
+static DEFINE_SPINLOCK(blk_mq_cpu_notify_lock);
 
 static int blk_mq_main_cpu_notify(struct notifier_block *self,
 				  unsigned long action, void *hcpu)
@@ -25,7 +25,10 @@
 	struct blk_mq_cpu_notifier *notify;
 	int ret = NOTIFY_OK;
 
-	raw_spin_lock(&blk_mq_cpu_notify_lock);
+	if (action != CPU_POST_DEAD)
+		return NOTIFY_OK;
+
+	spin_lock(&blk_mq_cpu_notify_lock);
 
 	list_for_each_entry(notify, &blk_mq_cpu_notify_list, list) {
 		ret = notify->notify(notify->data, action, cpu);
@@ -33,7 +36,7 @@
 			break;
 	}
 
-	raw_spin_unlock(&blk_mq_cpu_notify_lock);
+	spin_unlock(&blk_mq_cpu_notify_lock);
 	return ret;
 }
 
@@ -41,16 +44,16 @@
 {
 	BUG_ON(!notifier->notify);
 
-	raw_spin_lock(&blk_mq_cpu_notify_lock);
+	spin_lock(&blk_mq_cpu_notify_lock);
 	list_add_tail(&notifier->list, &blk_mq_cpu_notify_list);
-	raw_spin_unlock(&blk_mq_cpu_notify_lock);
+	spin_unlock(&blk_mq_cpu_notify_lock);
 }
 
 void blk_mq_unregister_cpu_notifier(struct blk_mq_cpu_notifier *notifier)
 {
-	raw_spin_lock(&blk_mq_cpu_notify_lock);
+	spin_lock(&blk_mq_cpu_notify_lock);
 	list_del(&notifier->list);
-	raw_spin_unlock(&blk_mq_cpu_notify_lock);
+	spin_unlock(&blk_mq_cpu_notify_lock);
 }
 
 void blk_mq_init_cpu_notifier(struct blk_mq_cpu_notifier *notifier,
diff -Nur linux-3.18.12.orig/block/blk-mq.h linux-3.18.12/block/blk-mq.h
--- linux-3.18.12.orig/block/blk-mq.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/block/blk-mq.h	2015-04-26 13:32:22.383684003 -0500
@@ -73,7 +73,10 @@
 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
 					   unsigned int cpu)
 {
-	return per_cpu_ptr(q->queue_ctx, cpu);
+	struct blk_mq_ctx *ctx;
+
+	ctx = per_cpu_ptr(q->queue_ctx, cpu);
+	return ctx;
 }
 
 /*
@@ -84,12 +87,12 @@
  */
 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
 {
-	return __blk_mq_get_ctx(q, get_cpu());
+	return __blk_mq_get_ctx(q, get_cpu_light());
 }
 
 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
 {
-	put_cpu();
+	put_cpu_light();
 }
 
 struct blk_mq_alloc_data {
diff -Nur linux-3.18.12.orig/block/blk-softirq.c linux-3.18.12/block/blk-softirq.c
--- linux-3.18.12.orig/block/blk-softirq.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/block/blk-softirq.c	2015-04-26 13:32:22.387684003 -0500
@@ -51,6 +51,7 @@
 		raise_softirq_irqoff(BLOCK_SOFTIRQ);
 
 	local_irq_restore(flags);
+	preempt_check_resched_rt();
 }
 
 /*
@@ -93,6 +94,7 @@
 				 this_cpu_ptr(&blk_cpu_done));
 		raise_softirq_irqoff(BLOCK_SOFTIRQ);
 		local_irq_enable();
+		preempt_check_resched_rt();
 	}
 
 	return NOTIFY_OK;
@@ -150,6 +152,7 @@
 		goto do_local;
 
 	local_irq_restore(flags);
+	preempt_check_resched_rt();
 }
 
 /**
diff -Nur linux-3.18.12.orig/block/bounce.c linux-3.18.12/block/bounce.c
--- linux-3.18.12.orig/block/bounce.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/block/bounce.c	2015-04-26 13:32:22.387684003 -0500
@@ -54,11 +54,11 @@
 	unsigned long flags;
 	unsigned char *vto;
 
-	local_irq_save(flags);
+	local_irq_save_nort(flags);
 	vto = kmap_atomic(to->bv_page);
 	memcpy(vto + to->bv_offset, vfrom, to->bv_len);
 	kunmap_atomic(vto);
-	local_irq_restore(flags);
+	local_irq_restore_nort(flags);
 }
 
 #else /* CONFIG_HIGHMEM */
diff -Nur linux-3.18.12.orig/crypto/algapi.c linux-3.18.12/crypto/algapi.c
--- linux-3.18.12.orig/crypto/algapi.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/crypto/algapi.c	2015-04-26 13:32:22.387684003 -0500
@@ -698,13 +698,13 @@
 
 int crypto_register_notifier(struct notifier_block *nb)
 {
-	return blocking_notifier_chain_register(&crypto_chain, nb);
+	return srcu_notifier_chain_register(&crypto_chain, nb);
 }
 EXPORT_SYMBOL_GPL(crypto_register_notifier);
 
 int crypto_unregister_notifier(struct notifier_block *nb)
 {
-	return blocking_notifier_chain_unregister(&crypto_chain, nb);
+	return srcu_notifier_chain_unregister(&crypto_chain, nb);
 }
 EXPORT_SYMBOL_GPL(crypto_unregister_notifier);
 
diff -Nur linux-3.18.12.orig/crypto/api.c linux-3.18.12/crypto/api.c
--- linux-3.18.12.orig/crypto/api.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/crypto/api.c	2015-04-26 13:32:22.387684003 -0500
@@ -31,7 +31,7 @@
 DECLARE_RWSEM(crypto_alg_sem);
 EXPORT_SYMBOL_GPL(crypto_alg_sem);
 
-BLOCKING_NOTIFIER_HEAD(crypto_chain);
+SRCU_NOTIFIER_HEAD(crypto_chain);
 EXPORT_SYMBOL_GPL(crypto_chain);
 
 static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg);
@@ -236,10 +236,10 @@
 {
 	int ok;
 
-	ok = blocking_notifier_call_chain(&crypto_chain, val, v);
+	ok = srcu_notifier_call_chain(&crypto_chain, val, v);
 	if (ok == NOTIFY_DONE) {
 		request_module("cryptomgr");
-		ok = blocking_notifier_call_chain(&crypto_chain, val, v);
+		ok = srcu_notifier_call_chain(&crypto_chain, val, v);
 	}
 
 	return ok;
diff -Nur linux-3.18.12.orig/crypto/internal.h linux-3.18.12/crypto/internal.h
--- linux-3.18.12.orig/crypto/internal.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/crypto/internal.h	2015-04-26 13:32:22.387684003 -0500
@@ -48,7 +48,7 @@
 
 extern struct list_head crypto_alg_list;
 extern struct rw_semaphore crypto_alg_sem;
-extern struct blocking_notifier_head crypto_chain;
+extern struct srcu_notifier_head crypto_chain;
 
 #ifdef CONFIG_PROC_FS
 void __init crypto_init_proc(void);
@@ -142,7 +142,7 @@
 
 static inline void crypto_notify(unsigned long val, void *v)
 {
-	blocking_notifier_call_chain(&crypto_chain, val, v);
+	srcu_notifier_call_chain(&crypto_chain, val, v);
 }
 
 #endif	/* _CRYPTO_INTERNAL_H */
diff -Nur linux-3.18.12.orig/Documentation/hwlat_detector.txt linux-3.18.12/Documentation/hwlat_detector.txt
--- linux-3.18.12.orig/Documentation/hwlat_detector.txt	1969-12-31 18:00:00.000000000 -0600
+++ linux-3.18.12/Documentation/hwlat_detector.txt	2015-04-26 13:32:22.347684003 -0500
@@ -0,0 +1,64 @@
+Introduction:
+-------------
+
+The module hwlat_detector is a special purpose kernel module that is used to
+detect large system latencies induced by the behavior of certain underlying
+hardware or firmware, independent of Linux itself. The code was developed
+originally to detect SMIs (System Management Interrupts) on x86 systems,
+however there is nothing x86 specific about this patchset. It was
+originally written for use by the "RT" patch since the Real Time
+kernel is highly latency sensitive.
+
+SMIs are usually not serviced by the Linux kernel, which typically does not
+even know that they are occuring. SMIs are instead are set up by BIOS code
+and are serviced by BIOS code, usually for "critical" events such as
+management of thermal sensors and fans. Sometimes though, SMIs are used for
+other tasks and those tasks can spend an inordinate amount of time in the
+handler (sometimes measured in milliseconds). Obviously this is a problem if
+you are trying to keep event service latencies down in the microsecond range.
+
+The hardware latency detector works by hogging all of the cpus for configurable
+amounts of time (by calling stop_machine()), polling the CPU Time Stamp Counter
+for some period, then looking for gaps in the TSC data. Any gap indicates a
+time when the polling was interrupted and since the machine is stopped and
+interrupts turned off the only thing that could do that would be an SMI.
+
+Note that the SMI detector should *NEVER* be used in a production environment.
+It is intended to be run manually to determine if the hardware platform has a
+problem with long system firmware service routines.
+
+Usage:
+------
+
+Loading the module hwlat_detector passing the parameter "enabled=1" (or by
+setting the "enable" entry in "hwlat_detector" debugfs toggled on) is the only
+step required to start the hwlat_detector. It is possible to redefine the
+threshold in microseconds (us) above which latency spikes will be taken
+into account (parameter "threshold=").
+
+Example:
+
+	# modprobe hwlat_detector enabled=1 threshold=100
+
+After the module is loaded, it creates a directory named "hwlat_detector" under
+the debugfs mountpoint, "/debug/hwlat_detector" for this text. It is necessary
+to have debugfs mounted, which might be on /sys/debug on your system.
+
+The /debug/hwlat_detector interface contains the following files:
+
+count			- number of latency spikes observed since last reset
+enable			- a global enable/disable toggle (0/1), resets count
+max			- maximum hardware latency actually observed (usecs)
+sample			- a pipe from which to read current raw sample data
+			  in the format <timestamp> <latency observed usecs>
+			  (can be opened O_NONBLOCK for a single sample)
+threshold		- minimum latency value to be considered (usecs)
+width			- time period to sample with CPUs held (usecs)
+			  must be less than the total window size (enforced)
+window			- total period of sampling, width being inside (usecs)
+
+By default we will set width to 500,000 and window to 1,000,000, meaning that
+we will sample every 1,000,000 usecs (1s) for 500,000 usecs (0.5s). If we
+observe any latencies that exceed the threshold (initially 100 usecs),
+then we write to a global sample ring buffer of 8K samples, which is
+consumed by reading from the "sample" (pipe) debugfs file interface.
diff -Nur linux-3.18.12.orig/Documentation/sysrq.txt linux-3.18.12/Documentation/sysrq.txt
--- linux-3.18.12.orig/Documentation/sysrq.txt	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/Documentation/sysrq.txt	2015-04-26 13:32:22.347684003 -0500
@@ -59,10 +59,17 @@
 On other - If you know of the key combos for other architectures, please
            let me know so I can add them to this section.
 
-On all -  write a character to /proc/sysrq-trigger.  e.g.:
-
+On all -  write a character to /proc/sysrq-trigger, e.g.:
 		echo t > /proc/sysrq-trigger
 
+On all - Enable network SysRq by writing a cookie to icmp_echo_sysrq, e.g.
+		echo 0x01020304 >/proc/sys/net/ipv4/icmp_echo_sysrq
+	 Send an ICMP echo request with this pattern plus the particular
+	 SysRq command key. Example:
+		# ping -c1 -s57 -p0102030468
+	 will trigger the SysRq-H (help) command.
+
+
 *  What are the 'command' keys?
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 'b'     - Will immediately reboot the system without syncing or unmounting
diff -Nur linux-3.18.12.orig/Documentation/trace/histograms.txt linux-3.18.12/Documentation/trace/histograms.txt
--- linux-3.18.12.orig/Documentation/trace/histograms.txt	1969-12-31 18:00:00.000000000 -0600
+++ linux-3.18.12/Documentation/trace/histograms.txt	2015-04-26 13:32:22.351684003 -0500
@@ -0,0 +1,186 @@
+		Using the Linux Kernel Latency Histograms
+
+
+This document gives a short explanation how to enable, configure and use
+latency histograms. Latency histograms are primarily relevant in the
+context of real-time enabled kernels (CONFIG_PREEMPT/CONFIG_PREEMPT_RT)
+and are used in the quality management of the Linux real-time
+capabilities.
+
+
+* Purpose of latency histograms
+
+A latency histogram continuously accumulates the frequencies of latency
+data. There are two types of histograms
+- potential sources of latencies
+- effective latencies
+
+
+* Potential sources of latencies
+
+Potential sources of latencies are code segments where interrupts,
+preemption or both are disabled (aka critical sections). To create
+histograms of potential sources of latency, the kernel stores the time
+stamp at the start of a critical section, determines the time elapsed
+when the end of the section is reached, and increments the frequency
+counter of that latency value - irrespective of whether any concurrently
+running process is affected by latency or not.
+- Configuration items (in the Kernel hacking/Tracers submenu)
+  CONFIG_INTERRUPT_OFF_LATENCY
+  CONFIG_PREEMPT_OFF_LATENCY
+
+
+* Effective latencies
+
+Effective latencies are actually occuring during wakeup of a process. To
+determine effective latencies, the kernel stores the time stamp when a
+process is scheduled to be woken up, and determines the duration of the
+wakeup time shortly before control is passed over to this process. Note
+that the apparent latency in user space may be somewhat longer, since the
+process may be interrupted after control is passed over to it but before
+the execution in user space takes place. Simply measuring the interval
+between enqueuing and wakeup may also not appropriate in cases when a
+process is scheduled as a result of a timer expiration. The timer may have
+missed its deadline, e.g. due to disabled interrupts, but this latency
+would not be registered. Therefore, the offsets of missed timers are
+recorded in a separate histogram. If both wakeup latency and missed timer
+offsets are configured and enabled, a third histogram may be enabled that
+records the overall latency as a sum of the timer latency, if any, and the
+wakeup latency. This histogram is called "timerandwakeup".
+- Configuration items (in the Kernel hacking/Tracers submenu)
+  CONFIG_WAKEUP_LATENCY
+  CONFIG_MISSED_TIMER_OFSETS
+
+
+* Usage
+
+The interface to the administration of the latency histograms is located
+in the debugfs file system. To mount it, either enter
+
+mount -t sysfs nodev /sys
+mount -t debugfs nodev /sys/kernel/debug
+
+from shell command line level, or add
+
+nodev	/sys			sysfs	defaults	0 0
+nodev	/sys/kernel/debug	debugfs	defaults	0 0
+
+to the file /etc/fstab. All latency histogram related files are then
+available in the directory /sys/kernel/debug/tracing/latency_hist. A
+particular histogram type is enabled by writing non-zero to the related
+variable in the /sys/kernel/debug/tracing/latency_hist/enable directory.
+Select "preemptirqsoff" for the histograms of potential sources of
+latencies and "wakeup" for histograms of effective latencies etc. The
+histogram data - one per CPU - are available in the files
+
+/sys/kernel/debug/tracing/latency_hist/preemptoff/CPUx
+/sys/kernel/debug/tracing/latency_hist/irqsoff/CPUx
+/sys/kernel/debug/tracing/latency_hist/preemptirqsoff/CPUx
+/sys/kernel/debug/tracing/latency_hist/wakeup/CPUx
+/sys/kernel/debug/tracing/latency_hist/wakeup/sharedprio/CPUx
+/sys/kernel/debug/tracing/latency_hist/missed_timer_offsets/CPUx
+/sys/kernel/debug/tracing/latency_hist/timerandwakeup/CPUx
+
+The histograms are reset by writing non-zero to the file "reset" in a
+particular latency directory. To reset all latency data, use
+
+#!/bin/sh
+
+TRACINGDIR=/sys/kernel/debug/tracing
+HISTDIR=$TRACINGDIR/latency_hist
+
+if test -d $HISTDIR
+then
+  cd $HISTDIR
+  for i in `find . | grep /reset$`
+  do
+    echo 1 >$i
+  done
+fi
+
+
+* Data format
+
+Latency data are stored with a resolution of one microsecond. The
+maximum latency is 10,240 microseconds. The data are only valid, if the
+overflow register is empty. Every output line contains the latency in
+microseconds in the first row and the number of samples in the second
+row. To display only lines with a positive latency count, use, for
+example,
+
+grep -v " 0$" /sys/kernel/debug/tracing/latency_hist/preemptoff/CPU0
+
+#Minimum latency: 0 microseconds.
+#Average latency: 0 microseconds.
+#Maximum latency: 25 microseconds.
+#Total samples: 3104770694
+#There are 0 samples greater or equal than 10240 microseconds
+#usecs	         samples
+    0	      2984486876
+    1	        49843506
+    2	        58219047
+    3	         5348126
+    4	         2187960
+    5	         3388262
+    6	          959289
+    7	          208294
+    8	           40420
+    9	            4485
+   10	           14918
+   11	           18340
+   12	           25052
+   13	           19455
+   14	            5602
+   15	             969
+   16	              47
+   17	              18
+   18	              14
+   19	               1
+   20	               3
+   21	               2
+   22	               5
+   23	               2
+   25	               1
+
+
+* Wakeup latency of a selected process
+
+To only collect wakeup latency data of a particular process, write the
+PID of the requested process to
+
+/sys/kernel/debug/tracing/latency_hist/wakeup/pid
+
+PIDs are not considered, if this variable is set to 0.
+
+
+* Details of the process with the highest wakeup latency so far
+
+Selected data of the process that suffered from the highest wakeup
+latency that occurred in a particular CPU are available in the file
+
+/sys/kernel/debug/tracing/latency_hist/wakeup/max_latency-CPUx.
+
+In addition, other relevant system data at the time when the
+latency occurred are given.
+
+The format of the data is (all in one line):
+<PID> <Priority> <Latency> (<Timeroffset>) <Command> \
+<- <PID> <Priority> <Command> <Timestamp>
+
+The value of <Timeroffset> is only relevant in the combined timer
+and wakeup latency recording. In the wakeup recording, it is
+always 0, in the missed_timer_offsets recording, it is the same
+as <Latency>.
+
+When retrospectively searching for the origin of a latency and
+tracing was not enabled, it may be helpful to know the name and
+some basic data of the task that (finally) was switching to the
+late real-tlme task. In addition to the victim's data, also the
+data of the possible culprit are therefore displayed after the
+"<-" symbol.
+
+Finally, the timestamp of the time when the latency occurred
+in <seconds>.<microseconds> after the most recent system boot
+is provided.
+
+These data are also reset when the wakeup histogram is reset.
diff -Nur linux-3.18.12.orig/drivers/acpi/acpica/acglobal.h linux-3.18.12/drivers/acpi/acpica/acglobal.h
--- linux-3.18.12.orig/drivers/acpi/acpica/acglobal.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/acpi/acpica/acglobal.h	2015-04-26 13:32:22.387684003 -0500
@@ -112,7 +112,7 @@
  * interrupt level
  */
 ACPI_GLOBAL(acpi_spinlock, acpi_gbl_gpe_lock);	/* For GPE data structs and registers */
-ACPI_GLOBAL(acpi_spinlock, acpi_gbl_hardware_lock);	/* For ACPI H/W except GPE registers */
+ACPI_GLOBAL(acpi_raw_spinlock, acpi_gbl_hardware_lock);	/* For ACPI H/W except GPE registers */
 ACPI_GLOBAL(acpi_spinlock, acpi_gbl_reference_count_lock);
 
 /* Mutex for _OSI support */
diff -Nur linux-3.18.12.orig/drivers/acpi/acpica/hwregs.c linux-3.18.12/drivers/acpi/acpica/hwregs.c
--- linux-3.18.12.orig/drivers/acpi/acpica/hwregs.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/acpi/acpica/hwregs.c	2015-04-26 13:32:22.387684003 -0500
@@ -269,14 +269,14 @@
 			  ACPI_BITMASK_ALL_FIXED_STATUS,
 			  ACPI_FORMAT_UINT64(acpi_gbl_xpm1a_status.address)));
 
-	lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock);
+	raw_spin_lock_irqsave(acpi_gbl_hardware_lock, lock_flags);
 
 	/* Clear the fixed events in PM1 A/B */
 
 	status = acpi_hw_register_write(ACPI_REGISTER_PM1_STATUS,
 					ACPI_BITMASK_ALL_FIXED_STATUS);
 
-	acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags);
+	raw_spin_unlock_irqrestore(acpi_gbl_hardware_lock, lock_flags);
 
 	if (ACPI_FAILURE(status)) {
 		goto exit;
diff -Nur linux-3.18.12.orig/drivers/acpi/acpica/hwxface.c linux-3.18.12/drivers/acpi/acpica/hwxface.c
--- linux-3.18.12.orig/drivers/acpi/acpica/hwxface.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/acpi/acpica/hwxface.c	2015-04-26 13:32:22.387684003 -0500
@@ -374,7 +374,7 @@
 		return_ACPI_STATUS(AE_BAD_PARAMETER);
 	}
 
-	lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock);
+	raw_spin_lock_irqsave(acpi_gbl_hardware_lock, lock_flags);
 
 	/*
 	 * At this point, we know that the parent register is one of the
@@ -435,7 +435,7 @@
 
 unlock_and_exit:
 
-	acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags);
+	raw_spin_unlock_irqrestore(acpi_gbl_hardware_lock, lock_flags);
 	return_ACPI_STATUS(status);
 }
 
diff -Nur linux-3.18.12.orig/drivers/acpi/acpica/utmutex.c linux-3.18.12/drivers/acpi/acpica/utmutex.c
--- linux-3.18.12.orig/drivers/acpi/acpica/utmutex.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/acpi/acpica/utmutex.c	2015-04-26 13:32:22.387684003 -0500
@@ -88,7 +88,7 @@
 		return_ACPI_STATUS (status);
 	}
 
-	status = acpi_os_create_lock (&acpi_gbl_hardware_lock);
+	status = acpi_os_create_raw_lock (&acpi_gbl_hardware_lock);
 	if (ACPI_FAILURE (status)) {
 		return_ACPI_STATUS (status);
 	}
@@ -141,7 +141,7 @@
 	/* Delete the spinlocks */
 
 	acpi_os_delete_lock(acpi_gbl_gpe_lock);
-	acpi_os_delete_lock(acpi_gbl_hardware_lock);
+	acpi_os_delete_raw_lock(acpi_gbl_hardware_lock);
 	acpi_os_delete_lock(acpi_gbl_reference_count_lock);
 
 	/* Delete the reader/writer lock */
diff -Nur linux-3.18.12.orig/drivers/ata/libata-sff.c linux-3.18.12/drivers/ata/libata-sff.c
--- linux-3.18.12.orig/drivers/ata/libata-sff.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/ata/libata-sff.c	2015-04-26 13:32:22.387684003 -0500
@@ -678,9 +678,9 @@
 	unsigned long flags;
 	unsigned int consumed;
 
-	local_irq_save(flags);
+	local_irq_save_nort(flags);
 	consumed = ata_sff_data_xfer32(dev, buf, buflen, rw);
-	local_irq_restore(flags);
+	local_irq_restore_nort(flags);
 
 	return consumed;
 }
@@ -719,7 +719,7 @@
 		unsigned long flags;
 
 		/* FIXME: use a bounce buffer */
-		local_irq_save(flags);
+		local_irq_save_nort(flags);
 		buf = kmap_atomic(page);
 
 		/* do the actual data transfer */
@@ -727,7 +727,7 @@
 				       do_write);
 
 		kunmap_atomic(buf);
-		local_irq_restore(flags);
+		local_irq_restore_nort(flags);
 	} else {
 		buf = page_address(page);
 		ap->ops->sff_data_xfer(qc->dev, buf + offset, qc->sect_size,
@@ -864,7 +864,7 @@
 		unsigned long flags;
 
 		/* FIXME: use bounce buffer */
-		local_irq_save(flags);
+		local_irq_save_nort(flags);
 		buf = kmap_atomic(page);
 
 		/* do the actual data transfer */
@@ -872,7 +872,7 @@
 								count, rw);
 
 		kunmap_atomic(buf);
-		local_irq_restore(flags);
+		local_irq_restore_nort(flags);
 	} else {
 		buf = page_address(page);
 		consumed = ap->ops->sff_data_xfer(dev,  buf + offset,
diff -Nur linux-3.18.12.orig/drivers/char/random.c linux-3.18.12/drivers/char/random.c
--- linux-3.18.12.orig/drivers/char/random.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/char/random.c	2015-04-26 13:32:22.387684003 -0500
@@ -776,8 +776,6 @@
 	} sample;
 	long delta, delta2, delta3;
 
-	preempt_disable();
-
 	sample.jiffies = jiffies;
 	sample.cycles = random_get_entropy();
 	sample.num = num;
@@ -818,7 +816,6 @@
 		 */
 		credit_entropy_bits(r, min_t(int, fls(delta>>1), 11));
 	}
-	preempt_enable();
 }
 
 void add_input_randomness(unsigned int type, unsigned int code,
@@ -871,28 +868,27 @@
 	return *(ptr + f->reg_idx++);
 }
 
-void add_interrupt_randomness(int irq, int irq_flags)
+void add_interrupt_randomness(int irq, int irq_flags, __u64 ip)
 {
 	struct entropy_store	*r;
 	struct fast_pool	*fast_pool = this_cpu_ptr(&irq_randomness);
-	struct pt_regs		*regs = get_irq_regs();
 	unsigned long		now = jiffies;
 	cycles_t		cycles = random_get_entropy();
 	__u32			c_high, j_high;
-	__u64			ip;
 	unsigned long		seed;
 	int			credit = 0;
 
 	if (cycles == 0)
-		cycles = get_reg(fast_pool, regs);
+		cycles = get_reg(fast_pool, NULL);
 	c_high = (sizeof(cycles) > 4) ? cycles >> 32 : 0;
 	j_high = (sizeof(now) > 4) ? now >> 32 : 0;
 	fast_pool->pool[0] ^= cycles ^ j_high ^ irq;
 	fast_pool->pool[1] ^= now ^ c_high;
-	ip = regs ? instruction_pointer(regs) : _RET_IP_;
+	if (!ip)
+		ip = _RET_IP_;
 	fast_pool->pool[2] ^= ip;
 	fast_pool->pool[3] ^= (sizeof(ip) > 4) ? ip >> 32 :
-		get_reg(fast_pool, regs);
+		get_reg(fast_pool, NULL);
 
 	fast_mix(fast_pool);
 	add_interrupt_bench(cycles);
diff -Nur linux-3.18.12.orig/drivers/clocksource/tcb_clksrc.c linux-3.18.12/drivers/clocksource/tcb_clksrc.c
--- linux-3.18.12.orig/drivers/clocksource/tcb_clksrc.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/clocksource/tcb_clksrc.c	2015-04-26 13:32:22.387684003 -0500
@@ -23,8 +23,7 @@
  *     this 32 bit free-running counter. the second channel is not used.
  *
  *   - The third channel may be used to provide a 16-bit clockevent
- *     source, used in either periodic or oneshot mode.  This runs
- *     at 32 KiHZ, and can handle delays of up to two seconds.
+ *     source, used in either periodic or oneshot mode.
  *
  * A boot clocksource and clockevent source are also currently needed,
  * unless the relevant platforms (ARM/AT91, AVR32/AT32) are changed so
@@ -74,6 +73,7 @@
 struct tc_clkevt_device {
 	struct clock_event_device	clkevt;
 	struct clk			*clk;
+	u32				freq;
 	void __iomem			*regs;
 };
 
@@ -82,13 +82,6 @@
 	return container_of(clkevt, struct tc_clkevt_device, clkevt);
 }
 
-/* For now, we always use the 32K clock ... this optimizes for NO_HZ,
- * because using one of the divided clocks would usually mean the
- * tick rate can never be less than several dozen Hz (vs 0.5 Hz).
- *
- * A divided clock could be good for high resolution timers, since
- * 30.5 usec resolution can seem "low".
- */
 static u32 timer_clock;
 
 static void tc_mode(enum clock_event_mode m, struct clock_event_device *d)
@@ -111,11 +104,12 @@
 	case CLOCK_EVT_MODE_PERIODIC:
 		clk_enable(tcd->clk);
 
-		/* slow clock, count up to RC, then irq and restart */
+		/* count up to RC, then irq and restart */
 		__raw_writel(timer_clock
 				| ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO,
 				regs + ATMEL_TC_REG(2, CMR));
-		__raw_writel((32768 + HZ/2) / HZ, tcaddr + ATMEL_TC_REG(2, RC));
+		__raw_writel((tcd->freq + HZ / 2) / HZ,
+			     tcaddr + ATMEL_TC_REG(2, RC));
 
 		/* Enable clock and interrupts on RC compare */
 		__raw_writel(ATMEL_TC_CPCS, regs + ATMEL_TC_REG(2, IER));
@@ -128,7 +122,7 @@
 	case CLOCK_EVT_MODE_ONESHOT:
 		clk_enable(tcd->clk);
 
-		/* slow clock, count up to RC, then irq and stop */
+		/* count up to RC, then irq and stop */
 		__raw_writel(timer_clock | ATMEL_TC_CPCSTOP
 				| ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO,
 				regs + ATMEL_TC_REG(2, CMR));
@@ -157,8 +151,12 @@
 		.name		= "tc_clkevt",
 		.features	= CLOCK_EVT_FEAT_PERIODIC
 					| CLOCK_EVT_FEAT_ONESHOT,
+#ifdef CONFIG_ATMEL_TCB_CLKSRC_USE_SLOW_CLOCK
 		/* Should be lower than at91rm9200's system timer */
 		.rating		= 125,
+#else
+		.rating		= 200,
+#endif
 		.set_next_event	= tc_next_event,
 		.set_mode	= tc_mode,
 	},
@@ -178,8 +176,9 @@
 	return IRQ_NONE;
 }
 
-static int __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
+static int __init setup_clkevents(struct atmel_tc *tc, int divisor_idx)
 {
+	unsigned divisor = atmel_tc_divisors[divisor_idx];
 	int ret;
 	struct clk *t2_clk = tc->clk[2];
 	int irq = tc->irq[2];
@@ -193,7 +192,11 @@
 	clkevt.regs = tc->regs;
 	clkevt.clk = t2_clk;
 
-	timer_clock = clk32k_divisor_idx;
+	timer_clock = divisor_idx;
+	if (!divisor)
+		clkevt.freq = 32768;
+	else
+		clkevt.freq = clk_get_rate(t2_clk) / divisor;
 
 	clkevt.clkevt.cpumask = cpumask_of(0);
 
@@ -203,7 +206,7 @@
 		return ret;
 	}
 
-	clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff);
+	clockevents_config_and_register(&clkevt.clkevt, clkevt.freq, 1, 0xffff);
 
 	return ret;
 }
@@ -340,7 +343,11 @@
 		goto err_disable_t1;
 
 	/* channel 2:  periodic and oneshot timer support */
+#ifdef CONFIG_ATMEL_TCB_CLKSRC_USE_SLOW_CLOCK
 	ret = setup_clkevents(tc, clk32k_divisor_idx);
+#else
+	ret = setup_clkevents(tc, best_divisor_idx);
+#endif
 	if (ret)
 		goto err_unregister_clksrc;
 
diff -Nur linux-3.18.12.orig/drivers/clocksource/timer-atmel-pit.c linux-3.18.12/drivers/clocksource/timer-atmel-pit.c
--- linux-3.18.12.orig/drivers/clocksource/timer-atmel-pit.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/clocksource/timer-atmel-pit.c	2015-04-26 13:32:22.387684003 -0500
@@ -90,6 +90,7 @@
 	return elapsed;
 }
 
+static struct irqaction at91sam926x_pit_irq;
 /*
  * Clockevent device:  interrupts every 1/HZ (== pit_cycles * MCK/16)
  */
@@ -100,6 +101,8 @@
 
 	switch (mode) {
 	case CLOCK_EVT_MODE_PERIODIC:
+		/* Set up irq handler */
+		setup_irq(at91sam926x_pit_irq.irq, &at91sam926x_pit_irq);
 		/* update clocksource counter */
 		data->cnt += data->cycle * PIT_PICNT(pit_read(data->base, AT91_PIT_PIVR));
 		pit_write(data->base, AT91_PIT_MR,
@@ -113,6 +116,7 @@
 		/* disable irq, leaving the clocksource active */
 		pit_write(data->base, AT91_PIT_MR,
 			  (data->cycle - 1) | AT91_PIT_PITEN);
+		remove_irq(at91sam926x_pit_irq.irq, &at91sam926x_pit_irq);
 		break;
 	case CLOCK_EVT_MODE_RESUME:
 		break;
diff -Nur linux-3.18.12.orig/drivers/cpufreq/Kconfig.x86 linux-3.18.12/drivers/cpufreq/Kconfig.x86
--- linux-3.18.12.orig/drivers/cpufreq/Kconfig.x86	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/cpufreq/Kconfig.x86	2015-04-26 13:32:22.387684003 -0500
@@ -113,7 +113,7 @@
 
 config X86_POWERNOW_K8
 	tristate "AMD Opteron/Athlon64 PowerNow!"
-	depends on ACPI && ACPI_PROCESSOR && X86_ACPI_CPUFREQ
+	depends on ACPI && ACPI_PROCESSOR && X86_ACPI_CPUFREQ && !PREEMPT_RT_BASE
 	help
 	  This adds the CPUFreq driver for K8/early Opteron/Athlon64 processors.
 	  Support for K10 and newer processors is now in acpi-cpufreq.
diff -Nur linux-3.18.12.orig/drivers/gpio/gpio-omap.c linux-3.18.12/drivers/gpio/gpio-omap.c
--- linux-3.18.12.orig/drivers/gpio/gpio-omap.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/gpio/gpio-omap.c	2015-04-26 13:32:22.387684003 -0500
@@ -57,7 +57,7 @@
 	u32 saved_datain;
 	u32 level_mask;
 	u32 toggle_mask;
-	spinlock_t lock;
+	raw_spinlock_t lock;
 	struct gpio_chip chip;
 	struct clk *dbck;
 	u32 mod_usage;
@@ -503,19 +503,19 @@
 		(type & (IRQ_TYPE_LEVEL_LOW|IRQ_TYPE_LEVEL_HIGH)))
 		return -EINVAL;
 
-	spin_lock_irqsave(&bank->lock, flags);
+	raw_spin_lock_irqsave(&bank->lock, flags);
 	offset = GPIO_INDEX(bank, gpio);
 	retval = omap_set_gpio_triggering(bank, offset, type);
 	if (!LINE_USED(bank->mod_usage, offset)) {
 		omap_enable_gpio_module(bank, offset);
 		omap_set_gpio_direction(bank, offset, 1);
 	} else if (!omap_gpio_is_input(bank, BIT(offset))) {
-		spin_unlock_irqrestore(&bank->lock, flags);
+		raw_spin_unlock_irqrestore(&bank->lock, flags);
 		return -EINVAL;
 	}
 
 	bank->irq_usage |= BIT(GPIO_INDEX(bank, gpio));
-	spin_unlock_irqrestore(&bank->lock, flags);
+	raw_spin_unlock_irqrestore(&bank->lock, flags);
 
 	if (type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH))
 		__irq_set_handler_locked(d->irq, handle_level_irq);
@@ -633,14 +633,14 @@
 		return -EINVAL;
 	}
 
-	spin_lock_irqsave(&bank->lock, flags);
+	raw_spin_lock_irqsave(&bank->lock, flags);
 	if (enable)
 		bank->context.wake_en |= gpio_bit;
 	else
 		bank->context.wake_en &= ~gpio_bit;
 
 	writel_relaxed(bank->context.wake_en, bank->base + bank->regs->wkup_en);
-	spin_unlock_irqrestore(&bank->lock, flags);
+	raw_spin_unlock_irqrestore(&bank->lock, flags);
 
 	return 0;
 }
@@ -675,7 +675,7 @@
 	if (!BANK_USED(bank))
 		pm_runtime_get_sync(bank->dev);
 
-	spin_lock_irqsave(&bank->lock, flags);
+	raw_spin_lock_irqsave(&bank->lock, flags);
 	/* Set trigger to none. You need to enable the desired trigger with
 	 * request_irq() or set_irq_type(). Only do this if the IRQ line has
 	 * not already been requested.
@@ -685,7 +685,7 @@
 		omap_enable_gpio_module(bank, offset);
 	}
 	bank->mod_usage |= BIT(offset);
-	spin_unlock_irqrestore(&bank->lock, flags);
+	raw_spin_unlock_irqrestore(&bank->lock, flags);
 
 	return 0;
 }
@@ -695,11 +695,11 @@
 	struct gpio_bank *bank = container_of(chip, struct gpio_bank, chip);
 	unsigned long flags;
 
-	spin_lock_irqsave(&bank->lock, flags);
+	raw_spin_lock_irqsave(&bank->lock, flags);
 	bank->mod_usage &= ~(BIT(offset));
 	omap_disable_gpio_module(bank, offset);
 	omap_reset_gpio(bank, bank->chip.base + offset);
-	spin_unlock_irqrestore(&bank->lock, flags);
+	raw_spin_unlock_irqrestore(&bank->lock, flags);
 
 	/*
 	 * If this is the last gpio to be freed in the bank,
@@ -799,12 +799,12 @@
 	unsigned long flags;
 	unsigned offset = GPIO_INDEX(bank, gpio);
 
-	spin_lock_irqsave(&bank->lock, flags);
+	raw_spin_lock_irqsave(&bank->lock, flags);
 	gpio_unlock_as_irq(&bank->chip, offset);
 	bank->irq_usage &= ~(BIT(offset));
 	omap_disable_gpio_module(bank, offset);
 	omap_reset_gpio(bank, gpio);
-	spin_unlock_irqrestore(&bank->lock, flags);
+	raw_spin_unlock_irqrestore(&bank->lock, flags);
 
 	/*
 	 * If this is the last IRQ to be freed in the bank,
@@ -828,10 +828,10 @@
 	unsigned int gpio = omap_irq_to_gpio(bank, d->hwirq);
 	unsigned long flags;
 
-	spin_lock_irqsave(&bank->lock, flags);
+	raw_spin_lock_irqsave(&bank->lock, flags);
 	omap_set_gpio_irqenable(bank, gpio, 0);
 	omap_set_gpio_triggering(bank, GPIO_INDEX(bank, gpio), IRQ_TYPE_NONE);
-	spin_unlock_irqrestore(&bank->lock, flags);
+	raw_spin_unlock_irqrestore(&bank->lock, flags);
 }
 
 static void omap_gpio_unmask_irq(struct irq_data *d)
@@ -842,7 +842,7 @@
 	u32 trigger = irqd_get_trigger_type(d);
 	unsigned long flags;
 
-	spin_lock_irqsave(&bank->lock, flags);
+	raw_spin_lock_irqsave(&bank->lock, flags);
 	if (trigger)
 		omap_set_gpio_triggering(bank, GPIO_INDEX(bank, gpio), trigger);
 
@@ -854,7 +854,7 @@
 	}
 
 	omap_set_gpio_irqenable(bank, gpio, 1);
-	spin_unlock_irqrestore(&bank->lock, flags);
+	raw_spin_unlock_irqrestore(&bank->lock, flags);
 }
 
 /*---------------------------------------------------------------------*/
@@ -867,9 +867,9 @@
 					OMAP_MPUIO_GPIO_MASKIT / bank->stride;
 	unsigned long		flags;
 
-	spin_lock_irqsave(&bank->lock, flags);
+	raw_spin_lock_irqsave(&bank->lock, flags);
 	writel_relaxed(0xffff & ~bank->context.wake_en, mask_reg);
-	spin_unlock_irqrestore(&bank->lock, flags);
+	raw_spin_unlock_irqrestore(&bank->lock, flags);
 
 	return 0;
 }
@@ -882,9 +882,9 @@
 					OMAP_MPUIO_GPIO_MASKIT / bank->stride;
 	unsigned long		flags;
 
-	spin_lock_irqsave(&bank->lock, flags);
+	raw_spin_lock_irqsave(&bank->lock, flags);
 	writel_relaxed(bank->context.wake_en, mask_reg);
-	spin_unlock_irqrestore(&bank->lock, flags);
+	raw_spin_unlock_irqrestore(&bank->lock, flags);
 
 	return 0;
 }
@@ -930,9 +930,9 @@
 
 	bank = container_of(chip, struct gpio_bank, chip);
 	reg = bank->base + bank->regs->direction;
-	spin_lock_irqsave(&bank->lock, flags);
+	raw_spin_lock_irqsave(&bank->lock, flags);
 	dir = !!(readl_relaxed(reg) & BIT(offset));
-	spin_unlock_irqrestore(&bank->lock, flags);
+	raw_spin_unlock_irqrestore(&bank->lock, flags);
 	return dir;
 }
 
@@ -942,9 +942,9 @@
 	unsigned long flags;
 
 	bank = container_of(chip, struct gpio_bank, chip);
-	spin_lock_irqsave(&bank->lock, flags);
+	raw_spin_lock_irqsave(&bank->lock, flags);
 	omap_set_gpio_direction(bank, offset, 1);
-	spin_unlock_irqrestore(&bank->lock, flags);
+	raw_spin_unlock_irqrestore(&bank->lock, flags);
 	return 0;
 }
 
@@ -968,10 +968,10 @@
 	unsigned long flags;
 
 	bank = container_of(chip, struct gpio_bank, chip);
-	spin_lock_irqsave(&bank->lock, flags);
+	raw_spin_lock_irqsave(&bank->lock, flags);
 	bank->set_dataout(bank, offset, value);
 	omap_set_gpio_direction(bank, offset, 0);
-	spin_unlock_irqrestore(&bank->lock, flags);
+	raw_spin_unlock_irqrestore(&bank->lock, flags);
 	return 0;
 }
 
@@ -983,9 +983,9 @@
 
 	bank = container_of(chip, struct gpio_bank, chip);
 
-	spin_lock_irqsave(&bank->lock, flags);
+	raw_spin_lock_irqsave(&bank->lock, flags);
 	omap2_set_gpio_debounce(bank, offset, debounce);
-	spin_unlock_irqrestore(&bank->lock, flags);
+	raw_spin_unlock_irqrestore(&bank->lock, flags);
 
 	return 0;
 }
@@ -996,9 +996,9 @@
 	unsigned long flags;
 
 	bank = container_of(chip, struct gpio_bank, chip);
-	spin_lock_irqsave(&bank->lock, flags);
+	raw_spin_lock_irqsave(&bank->lock, flags);
 	bank->set_dataout(bank, offset, value);
-	spin_unlock_irqrestore(&bank->lock, flags);
+	raw_spin_unlock_irqrestore(&bank->lock, flags);
 }
 
 /*---------------------------------------------------------------------*/
@@ -1223,7 +1223,7 @@
 	else
 		bank->set_dataout = omap_set_gpio_dataout_mask;
 
-	spin_lock_init(&bank->lock);
+	raw_spin_lock_init(&bank->lock);
 
 	/* Static mapping, never released */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -1270,7 +1270,7 @@
 	unsigned long flags;
 	u32 wake_low, wake_hi;
 
-	spin_lock_irqsave(&bank->lock, flags);
+	raw_spin_lock_irqsave(&bank->lock, flags);
 
 	/*
 	 * Only edges can generate a wakeup event to the PRCM.
@@ -1323,7 +1323,7 @@
 				bank->get_context_loss_count(bank->dev);
 
 	omap_gpio_dbck_disable(bank);
-	spin_unlock_irqrestore(&bank->lock, flags);
+	raw_spin_unlock_irqrestore(&bank->lock, flags);
 
 	return 0;
 }
@@ -1338,7 +1338,7 @@
 	unsigned long flags;
 	int c;
 
-	spin_lock_irqsave(&bank->lock, flags);
+	raw_spin_lock_irqsave(&bank->lock, flags);
 
 	/*
 	 * On the first resume during the probe, the context has not
@@ -1374,14 +1374,14 @@
 			if (c != bank->context_loss_count) {
 				omap_gpio_restore_context(bank);
 			} else {
-				spin_unlock_irqrestore(&bank->lock, flags);
+				raw_spin_unlock_irqrestore(&bank->lock, flags);
 				return 0;
 			}
 		}
 	}
 
 	if (!bank->workaround_enabled) {
-		spin_unlock_irqrestore(&bank->lock, flags);
+		raw_spin_unlock_irqrestore(&bank->lock, flags);
 		return 0;
 	}
 
@@ -1436,7 +1436,7 @@
 	}
 
 	bank->workaround_enabled = false;
-	spin_unlock_irqrestore(&bank->lock, flags);
+	raw_spin_unlock_irqrestore(&bank->lock, flags);
 
 	return 0;
 }
diff -Nur linux-3.18.12.orig/drivers/gpu/drm/i915/i915_gem.c linux-3.18.12/drivers/gpu/drm/i915/i915_gem.c
--- linux-3.18.12.orig/drivers/gpu/drm/i915/i915_gem.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/gpu/drm/i915/i915_gem.c	2015-04-26 13:32:22.391684003 -0500
@@ -5144,7 +5144,7 @@
 	if (!mutex_is_locked(mutex))
 		return false;
 
-#if defined(CONFIG_SMP) && !defined(CONFIG_DEBUG_MUTEXES)
+#if defined(CONFIG_SMP) && !defined(CONFIG_DEBUG_MUTEXES) && !defined(CONFIG_PREEMPT_RT_BASE)
 	return mutex->owner == task;
 #else
 	/* Since UP may be pre-empted, we cannot assume that we own the lock */
diff -Nur linux-3.18.12.orig/drivers/gpu/drm/i915/i915_gem_execbuffer.c linux-3.18.12/drivers/gpu/drm/i915/i915_gem_execbuffer.c
--- linux-3.18.12.orig/drivers/gpu/drm/i915/i915_gem_execbuffer.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/gpu/drm/i915/i915_gem_execbuffer.c	2015-04-26 13:32:22.391684003 -0500
@@ -1170,7 +1170,9 @@
 			return ret;
 	}
 
+#ifndef CONFIG_PREEMPT_RT_BASE
 	trace_i915_gem_ring_dispatch(ring, intel_ring_get_seqno(ring), flags);
+#endif
 
 	i915_gem_execbuffer_move_to_active(vmas, ring);
 	i915_gem_execbuffer_retire_commands(dev, file, ring, batch_obj);
diff -Nur linux-3.18.12.orig/drivers/i2c/busses/i2c-omap.c linux-3.18.12/drivers/i2c/busses/i2c-omap.c
--- linux-3.18.12.orig/drivers/i2c/busses/i2c-omap.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/i2c/busses/i2c-omap.c	2015-04-26 13:32:22.391684003 -0500
@@ -875,15 +875,12 @@
 	u16 mask;
 	u16 stat;
 
-	spin_lock(&dev->lock);
-	mask = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
 	stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
+	mask = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
 
 	if (stat & mask)
 		ret = IRQ_WAKE_THREAD;
 
-	spin_unlock(&dev->lock);
-
 	return ret;
 }
 
diff -Nur linux-3.18.12.orig/drivers/ide/alim15x3.c linux-3.18.12/drivers/ide/alim15x3.c
--- linux-3.18.12.orig/drivers/ide/alim15x3.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/ide/alim15x3.c	2015-04-26 13:32:22.391684003 -0500
@@ -234,7 +234,7 @@
 
 	isa_dev = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533, NULL);
 
-	local_irq_save(flags);
+	local_irq_save_nort(flags);
 
 	if (m5229_revision < 0xC2) {
 		/*
@@ -325,7 +325,7 @@
 	}
 	pci_dev_put(north);
 	pci_dev_put(isa_dev);
-	local_irq_restore(flags);
+	local_irq_restore_nort(flags);
 	return 0;
 }
 
diff -Nur linux-3.18.12.orig/drivers/ide/hpt366.c linux-3.18.12/drivers/ide/hpt366.c
--- linux-3.18.12.orig/drivers/ide/hpt366.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/ide/hpt366.c	2015-04-26 13:32:22.391684003 -0500
@@ -1241,7 +1241,7 @@
 
 	dma_old = inb(base + 2);
 
-	local_irq_save(flags);
+	local_irq_save_nort(flags);
 
 	dma_new = dma_old;
 	pci_read_config_byte(dev, hwif->channel ? 0x4b : 0x43, &masterdma);
@@ -1252,7 +1252,7 @@
 	if (dma_new != dma_old)
 		outb(dma_new, base + 2);
 
-	local_irq_restore(flags);
+	local_irq_restore_nort(flags);
 
 	printk(KERN_INFO "    %s: BM-DMA at 0x%04lx-0x%04lx\n",
 			 hwif->name, base, base + 7);
diff -Nur linux-3.18.12.orig/drivers/ide/ide-io.c linux-3.18.12/drivers/ide/ide-io.c
--- linux-3.18.12.orig/drivers/ide/ide-io.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/ide/ide-io.c	2015-04-26 13:32:22.391684003 -0500
@@ -659,7 +659,7 @@
 		/* disable_irq_nosync ?? */
 		disable_irq(hwif->irq);
 		/* local CPU only, as if we were handling an interrupt */
-		local_irq_disable();
+		local_irq_disable_nort();
 		if (hwif->polling) {
 			startstop = handler(drive);
 		} else if (drive_is_ready(drive)) {
diff -Nur linux-3.18.12.orig/drivers/ide/ide-iops.c linux-3.18.12/drivers/ide/ide-iops.c
--- linux-3.18.12.orig/drivers/ide/ide-iops.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/ide/ide-iops.c	2015-04-26 13:32:22.391684003 -0500
@@ -129,12 +129,12 @@
 				if ((stat & ATA_BUSY) == 0)
 					break;
 
-				local_irq_restore(flags);
+				local_irq_restore_nort(flags);
 				*rstat = stat;
 				return -EBUSY;
 			}
 		}
-		local_irq_restore(flags);
+		local_irq_restore_nort(flags);
 	}
 	/*
 	 * Allow status to settle, then read it again.
diff -Nur linux-3.18.12.orig/drivers/ide/ide-io-std.c linux-3.18.12/drivers/ide/ide-io-std.c
--- linux-3.18.12.orig/drivers/ide/ide-io-std.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/ide/ide-io-std.c	2015-04-26 13:32:22.391684003 -0500
@@ -175,7 +175,7 @@
 		unsigned long uninitialized_var(flags);
 
 		if ((io_32bit & 2) && !mmio) {
-			local_irq_save(flags);
+			local_irq_save_nort(flags);
 			ata_vlb_sync(io_ports->nsect_addr);
 		}
 
@@ -186,7 +186,7 @@
 			insl(data_addr, buf, words);
 
 		if ((io_32bit & 2) && !mmio)
-			local_irq_restore(flags);
+			local_irq_restore_nort(flags);
 
 		if (((len + 1) & 3) < 2)
 			return;
@@ -219,7 +219,7 @@
 		unsigned long uninitialized_var(flags);
 
 		if ((io_32bit & 2) && !mmio) {
-			local_irq_save(flags);
+			local_irq_save_nort(flags);
 			ata_vlb_sync(io_ports->nsect_addr);
 		}
 
@@ -230,7 +230,7 @@
 			outsl(data_addr, buf, words);
 
 		if ((io_32bit & 2) && !mmio)
-			local_irq_restore(flags);
+			local_irq_restore_nort(flags);
 
 		if (((len + 1) & 3) < 2)
 			return;
diff -Nur linux-3.18.12.orig/drivers/ide/ide-probe.c linux-3.18.12/drivers/ide/ide-probe.c
--- linux-3.18.12.orig/drivers/ide/ide-probe.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/ide/ide-probe.c	2015-04-26 13:32:22.391684003 -0500
@@ -196,10 +196,10 @@
 	int bswap = 1;
 
 	/* local CPU only; some systems need this */
-	local_irq_save(flags);
+	local_irq_save_nort(flags);
 	/* read 512 bytes of id info */
 	hwif->tp_ops->input_data(drive, NULL, id, SECTOR_SIZE);
-	local_irq_restore(flags);
+	local_irq_restore_nort(flags);
 
 	drive->dev_flags |= IDE_DFLAG_ID_READ;
 #ifdef DEBUG
diff -Nur linux-3.18.12.orig/drivers/ide/ide-taskfile.c linux-3.18.12/drivers/ide/ide-taskfile.c
--- linux-3.18.12.orig/drivers/ide/ide-taskfile.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/ide/ide-taskfile.c	2015-04-26 13:32:22.391684003 -0500
@@ -250,7 +250,7 @@
 
 		page_is_high = PageHighMem(page);
 		if (page_is_high)
-			local_irq_save(flags);
+			local_irq_save_nort(flags);
 
 		buf = kmap_atomic(page) + offset;
 
@@ -271,7 +271,7 @@
 		kunmap_atomic(buf);
 
 		if (page_is_high)
-			local_irq_restore(flags);
+			local_irq_restore_nort(flags);
 
 		len -= nr_bytes;
 	}
@@ -414,7 +414,7 @@
 	}
 
 	if ((drive->dev_flags & IDE_DFLAG_UNMASK) == 0)
-		local_irq_disable();
+		local_irq_disable_nort();
 
 	ide_set_handler(drive, &task_pio_intr, WAIT_WORSTCASE);
 
diff -Nur linux-3.18.12.orig/drivers/infiniband/ulp/ipoib/ipoib_multicast.c linux-3.18.12/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
--- linux-3.18.12.orig/drivers/infiniband/ulp/ipoib/ipoib_multicast.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/infiniband/ulp/ipoib/ipoib_multicast.c	2015-04-26 13:32:22.391684003 -0500
@@ -796,7 +796,7 @@
 
 	ipoib_mcast_stop_thread(dev, 0);
 
-	local_irq_save(flags);
+	local_irq_save_nort(flags);
 	netif_addr_lock(dev);
 	spin_lock(&priv->lock);
 
@@ -878,7 +878,7 @@
 
 	spin_unlock(&priv->lock);
 	netif_addr_unlock(dev);
-	local_irq_restore(flags);
+	local_irq_restore_nort(flags);
 
 	/* We have to cancel outside of the spinlock */
 	list_for_each_entry_safe(mcast, tmcast, &remove_list, list) {
diff -Nur linux-3.18.12.orig/drivers/input/gameport/gameport.c linux-3.18.12/drivers/input/gameport/gameport.c
--- linux-3.18.12.orig/drivers/input/gameport/gameport.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/input/gameport/gameport.c	2015-04-26 13:32:22.391684003 -0500
@@ -124,12 +124,12 @@
 	tx = 1 << 30;
 
 	for(i = 0; i < 50; i++) {
-		local_irq_save(flags);
+		local_irq_save_nort(flags);
 		GET_TIME(t1);
 		for (t = 0; t < 50; t++) gameport_read(gameport);
 		GET_TIME(t2);
 		GET_TIME(t3);
-		local_irq_restore(flags);
+		local_irq_restore_nort(flags);
 		udelay(i * 10);
 		if ((t = DELTA(t2,t1) - DELTA(t3,t2)) < tx) tx = t;
 	}
@@ -148,11 +148,11 @@
 	tx = 1 << 30;
 
 	for(i = 0; i < 50; i++) {
-		local_irq_save(flags);
+		local_irq_save_nort(flags);
 		rdtscl(t1);
 		for (t = 0; t < 50; t++) gameport_read(gameport);
 		rdtscl(t2);
-		local_irq_restore(flags);
+		local_irq_restore_nort(flags);
 		udelay(i * 10);
 		if (t2 - t1 < tx) tx = t2 - t1;
 	}
diff -Nur linux-3.18.12.orig/drivers/leds/trigger/Kconfig linux-3.18.12/drivers/leds/trigger/Kconfig
--- linux-3.18.12.orig/drivers/leds/trigger/Kconfig	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/leds/trigger/Kconfig	2015-04-26 13:32:22.391684003 -0500
@@ -61,7 +61,7 @@
 
 config LEDS_TRIGGER_CPU
 	bool "LED CPU Trigger"
-	depends on LEDS_TRIGGERS
+	depends on LEDS_TRIGGERS && !PREEMPT_RT_BASE
 	help
 	  This allows LEDs to be controlled by active CPUs. This shows
 	  the active CPUs across an array of LEDs so you can see which
diff -Nur linux-3.18.12.orig/drivers/md/bcache/Kconfig linux-3.18.12/drivers/md/bcache/Kconfig
--- linux-3.18.12.orig/drivers/md/bcache/Kconfig	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/md/bcache/Kconfig	2015-04-26 13:32:22.391684003 -0500
@@ -1,6 +1,7 @@
 
 config BCACHE
 	tristate "Block device as cache"
+	depends on !PREEMPT_RT_FULL
 	---help---
 	Allows a block device to be used as cache for other devices; uses
 	a btree for indexing and the layout is optimized for SSDs.
diff -Nur linux-3.18.12.orig/drivers/md/dm.c linux-3.18.12/drivers/md/dm.c
--- linux-3.18.12.orig/drivers/md/dm.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/md/dm.c	2015-04-26 13:32:22.395684003 -0500
@@ -1898,14 +1898,14 @@
 		if (map_request(ti, clone, md))
 			goto requeued;
 
-		BUG_ON(!irqs_disabled());
+		BUG_ON_NONRT(!irqs_disabled());
 		spin_lock(q->queue_lock);
 	}
 
 	goto out;
 
 requeued:
-	BUG_ON(!irqs_disabled());
+	BUG_ON_NONRT(!irqs_disabled());
 	spin_lock(q->queue_lock);
 
 delay_and_out:
diff -Nur linux-3.18.12.orig/drivers/md/raid5.c linux-3.18.12/drivers/md/raid5.c
--- linux-3.18.12.orig/drivers/md/raid5.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/md/raid5.c	2015-04-26 13:32:22.395684003 -0500
@@ -1649,8 +1649,9 @@
 	struct raid5_percpu *percpu;
 	unsigned long cpu;
 
-	cpu = get_cpu();
+	cpu = get_cpu_light();
 	percpu = per_cpu_ptr(conf->percpu, cpu);
+	spin_lock(&percpu->lock);
 	if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) {
 		ops_run_biofill(sh);
 		overlap_clear++;
@@ -1702,7 +1703,8 @@
 			if (test_and_clear_bit(R5_Overlap, &dev->flags))
 				wake_up(&sh->raid_conf->wait_for_overlap);
 		}
-	put_cpu();
+	spin_unlock(&percpu->lock);
+	put_cpu_light();
 }
 
 static int grow_one_stripe(struct r5conf *conf, int hash)
@@ -5708,6 +5710,7 @@
 			       __func__, cpu);
 			break;
 		}
+		spin_lock_init(&per_cpu_ptr(conf->percpu, cpu)->lock);
 	}
 	put_online_cpus();
 
diff -Nur linux-3.18.12.orig/drivers/md/raid5.h linux-3.18.12/drivers/md/raid5.h
--- linux-3.18.12.orig/drivers/md/raid5.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/md/raid5.h	2015-04-26 13:32:22.395684003 -0500
@@ -457,6 +457,7 @@
 	int			recovery_disabled;
 	/* per cpu variables */
 	struct raid5_percpu {
+		spinlock_t	lock;	     /* Protection for -RT */
 		struct page	*spare_page; /* Used when checking P/Q in raid6 */
 		void		*scribble;   /* space for constructing buffer
 					      * lists and performing address
diff -Nur linux-3.18.12.orig/drivers/misc/hwlat_detector.c linux-3.18.12/drivers/misc/hwlat_detector.c
--- linux-3.18.12.orig/drivers/misc/hwlat_detector.c	1969-12-31 18:00:00.000000000 -0600
+++ linux-3.18.12/drivers/misc/hwlat_detector.c	2015-04-26 13:32:22.395684003 -0500
@@ -0,0 +1,1240 @@
+/*
+ * hwlat_detector.c - A simple Hardware Latency detector.
+ *
+ * Use this module to detect large system latencies induced by the behavior of
+ * certain underlying system hardware or firmware, independent of Linux itself.
+ * The code was developed originally to detect the presence of SMIs on Intel
+ * and AMD systems, although there is no dependency upon x86 herein.
+ *
+ * The classical example usage of this module is in detecting the presence of
+ * SMIs or System Management Interrupts on Intel and AMD systems. An SMI is a
+ * somewhat special form of hardware interrupt spawned from earlier CPU debug
+ * modes in which the (BIOS/EFI/etc.) firmware arranges for the South Bridge
+ * LPC (or other device) to generate a special interrupt under certain
+ * circumstances, for example, upon expiration of a special SMI timer device,
+ * due to certain external thermal readings, on certain I/O address accesses,
+ * and other situations. An SMI hits a special CPU pin, triggers a special
+ * SMI mode (complete with special memory map), and the OS is unaware.
+ *
+ * Although certain hardware-inducing latencies are necessary (for example,
+ * a modern system often requires an SMI handler for correct thermal control
+ * and remote management) they can wreak havoc upon any OS-level performance
+ * guarantees toward low-latency, especially when the OS is not even made
+ * aware of the presence of these interrupts. For this reason, we need a
+ * somewhat brute force mechanism to detect these interrupts. In this case,
+ * we do it by hogging all of the CPU(s) for configurable timer intervals,
+ * sampling the built-in CPU timer, looking for discontiguous readings.
+ *
+ * WARNING: This implementation necessarily introduces latencies. Therefore,
+ *          you should NEVER use this module in a production environment
+ *          requiring any kind of low-latency performance guarantee(s).
+ *
+ * Copyright (C) 2008-2009 Jon Masters, Red Hat, Inc. <jcm@redhat.com>
+ *
+ * Includes useful feedback from Clark Williams <clark@redhat.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/ring_buffer.h>
+#include <linux/time.h>
+#include <linux/hrtimer.h>
+#include <linux/kthread.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/uaccess.h>
+#include <linux/version.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/trace_clock.h>
+
+#define BUF_SIZE_DEFAULT	262144UL		/* 8K*(sizeof(entry)) */
+#define BUF_FLAGS		(RB_FL_OVERWRITE)	/* no block on full */
+#define U64STR_SIZE		22			/* 20 digits max */
+
+#define VERSION			"1.0.0"
+#define BANNER			"hwlat_detector: "
+#define DRVNAME			"hwlat_detector"
+#define DEFAULT_SAMPLE_WINDOW	1000000			/* 1s */
+#define DEFAULT_SAMPLE_WIDTH	500000			/* 0.5s */
+#define DEFAULT_LAT_THRESHOLD	10			/* 10us */
+
+/* Module metadata */
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jon Masters <jcm@redhat.com>");
+MODULE_DESCRIPTION("A simple hardware latency detector");
+MODULE_VERSION(VERSION);
+
+/* Module parameters */
+
+static int debug;
+static int enabled;
+static int threshold;
+
+module_param(debug, int, 0);			/* enable debug */
+module_param(enabled, int, 0);			/* enable detector */
+module_param(threshold, int, 0);		/* latency threshold */
+
+/* Buffering and sampling */
+
+static struct ring_buffer *ring_buffer;		/* sample buffer */
+static DEFINE_MUTEX(ring_buffer_mutex);		/* lock changes */
+static unsigned long buf_size = BUF_SIZE_DEFAULT;
+static struct task_struct *kthread;		/* sampling thread */
+
+/* DebugFS filesystem entries */
+
+static struct dentry *debug_dir;		/* debugfs directory */
+static struct dentry *debug_max;		/* maximum TSC delta */
+static struct dentry *debug_count;		/* total detect count */
+static struct dentry *debug_sample_width;	/* sample width us */
+static struct dentry *debug_sample_window;	/* sample window us */
+static struct dentry *debug_sample;		/* raw samples us */
+static struct dentry *debug_threshold;		/* threshold us */
+static struct dentry *debug_enable;		/* enable/disable */
+
+/* Individual samples and global state */
+
+struct sample;					/* latency sample */
+struct data;					/* Global state */
+
+/* Sampling functions */
+static int __buffer_add_sample(struct sample *sample);
+static struct sample *buffer_get_sample(struct sample *sample);
+
+/* Threading and state */
+static int kthread_fn(void *unused);
+static int start_kthread(void);
+static int stop_kthread(void);
+static void __reset_stats(void);
+static int init_stats(void);
+
+/* Debugfs interface */
+static ssize_t simple_data_read(struct file *filp, char __user *ubuf,
+				size_t cnt, loff_t *ppos, const u64 *entry);
+static ssize_t simple_data_write(struct file *filp, const char __user *ubuf,
+				 size_t cnt, loff_t *ppos, u64 *entry);
+static int debug_sample_fopen(struct inode *inode, struct file *filp);
+static ssize_t debug_sample_fread(struct file *filp, char __user *ubuf,
+				  size_t cnt, loff_t *ppos);
+static int debug_sample_release(struct inode *inode, struct file *filp);
+static int debug_enable_fopen(struct inode *inode, struct file *filp);
+static ssize_t debug_enable_fread(struct file *filp, char __user *ubuf,
+				  size_t cnt, loff_t *ppos);
+static ssize_t debug_enable_fwrite(struct file *file,
+				   const char __user *user_buffer,
+				   size_t user_size, loff_t *offset);
+
+/* Initialization functions */
+static int init_debugfs(void);
+static void free_debugfs(void);
+static int detector_init(void);
+static void detector_exit(void);
+
+/* Individual latency samples are stored here when detected and packed into
+ * the ring_buffer circular buffer, where they are overwritten when
+ * more than buf_size/sizeof(sample) samples are received. */
+struct sample {
+	u64		seqnum;		/* unique sequence */
+	u64		duration;	/* ktime delta */
+	u64		outer_duration;	/* ktime delta (outer loop) */
+	struct timespec	timestamp;	/* wall time */
+	unsigned long   lost;
+};
+
+/* keep the global state somewhere. */
+static struct data {
+
+	struct mutex lock;		/* protect changes */
+
+	u64	count;			/* total since reset */
+	u64	max_sample;		/* max hardware latency */
+	u64	threshold;		/* sample threshold level */
+
+	u64	sample_window;		/* total sampling window (on+off) */
+	u64	sample_width;		/* active sampling portion of window */
+
+	atomic_t sample_open;		/* whether the sample file is open */
+
+	wait_queue_head_t wq;		/* waitqeue for new sample values */
+
+} data;
+
+/**
+ * __buffer_add_sample - add a new latency sample recording to the ring buffer
+ * @sample: The new latency sample value
+ *
+ * This receives a new latency sample and records it in a global ring buffer.
+ * No additional locking is used in this case.
+ */
+static int __buffer_add_sample(struct sample *sample)
+{
+	return ring_buffer_write(ring_buffer,
+				 sizeof(struct sample), sample);
+}
+
+/**
+ * buffer_get_sample - remove a hardware latency sample from the ring buffer
+ * @sample: Pre-allocated storage for the sample
+ *
+ * This retrieves a hardware latency sample from the global circular buffer
+ */
+static struct sample *buffer_get_sample(struct sample *sample)
+{
+	struct ring_buffer_event *e = NULL;
+	struct sample *s = NULL;
+	unsigned int cpu = 0;
+
+	if (!sample)
+		return NULL;
+
+	mutex_lock(&ring_buffer_mutex);
+	for_each_online_cpu(cpu) {
+		e = ring_buffer_consume(ring_buffer, cpu, NULL, &sample->lost);
+		if (e)
+			break;
+	}
+
+	if (e) {
+		s = ring_buffer_event_data(e);
+		memcpy(sample, s, sizeof(struct sample));
+	} else
+		sample = NULL;
+	mutex_unlock(&ring_buffer_mutex);
+
+	return sample;
+}
+
+#ifndef CONFIG_TRACING
+#define time_type	ktime_t
+#define time_get()	ktime_get()
+#define time_to_us(x)	ktime_to_us(x)
+#define time_sub(a, b)	ktime_sub(a, b)
+#define init_time(a, b)	(a).tv64 = b
+#define time_u64(a)	((a).tv64)
+#else
+#define time_type	u64
+#define time_get()	trace_clock_local()
+#define time_to_us(x)	div_u64(x, 1000)
+#define time_sub(a, b)	((a) - (b))
+#define init_time(a, b)	(a = b)
+#define time_u64(a)	a
+#endif
+/**
+ * get_sample - sample the CPU TSC and look for likely hardware latencies
+ *
+ * Used to repeatedly capture the CPU TSC (or similar), looking for potential
+ * hardware-induced latency. Called with interrupts disabled and with
+ * data.lock held.
+ */
+static int get_sample(void)
+{
+	time_type start, t1, t2, last_t2;
+	s64 diff, total = 0;
+	u64 sample = 0;
+	u64 outer_sample = 0;
+	int ret = -1;
+
+	init_time(last_t2, 0);
+	start = time_get(); /* start timestamp */
+
+	do {
+
+		t1 = time_get();	/* we'll look for a discontinuity */
+		t2 = time_get();
+
+		if (time_u64(last_t2)) {
+			/* Check the delta from outer loop (t2 to next t1) */
+			diff = time_to_us(time_sub(t1, last_t2));
+			/* This shouldn't happen */
+			if (diff < 0) {
+				pr_err(BANNER "time running backwards\n");
+				goto out;
+			}
+			if (diff > outer_sample)
+				outer_sample = diff;
+		}
+		last_t2 = t2;
+
+		total = time_to_us(time_sub(t2, start)); /* sample width */
+
+		/* This checks the inner loop (t1 to t2) */
+		diff = time_to_us(time_sub(t2, t1));     /* current diff */
+
+		/* This shouldn't happen */
+		if (diff < 0) {
+			pr_err(BANNER "time running backwards\n");
+			goto out;
+		}
+
+		if (diff > sample)
+			sample = diff; /* only want highest value */
+
+	} while (total <= data.sample_width);
+
+	ret = 0;
+
+	/* If we exceed the threshold value, we have found a hardware latency */
+	if (sample > data.threshold || outer_sample > data.threshold) {
+		struct sample s;
+
+		ret = 1;
+
+		data.count++;
+		s.seqnum = data.count;
+		s.duration = sample;
+		s.outer_duration = outer_sample;
+		s.timestamp = CURRENT_TIME;
+		__buffer_add_sample(&s);
+
+		/* Keep a running maximum ever recorded hardware latency */
+		if (sample > data.max_sample)
+			data.max_sample = sample;
+	}
+
+out:
+	return ret;
+}
+
+/*
+ * kthread_fn - The CPU time sampling/hardware latency detection kernel thread
+ * @unused: A required part of the kthread API.
+ *
+ * Used to periodically sample the CPU TSC via a call to get_sample. We
+ * disable interrupts, which does (intentionally) introduce latency since we
+ * need to ensure nothing else might be running (and thus pre-empting).
+ * Obviously this should never be used in production environments.
+ *
+ * Currently this runs on which ever CPU it was scheduled on, but most
+ * real-worald hardware latency situations occur across several CPUs,
+ * but we might later generalize this if we find there are any actualy
+ * systems with alternate SMI delivery or other hardware latencies.
+ */
+static int kthread_fn(void *unused)
+{
+	int ret;
+	u64 interval;
+
+	while (!kthread_should_stop()) {
+
+		mutex_lock(&data.lock);
+
+		local_irq_disable();
+		ret = get_sample();
+		local_irq_enable();
+
+		if (ret > 0)
+			wake_up(&data.wq); /* wake up reader(s) */
+
+		interval = data.sample_window - data.sample_width;
+		do_div(interval, USEC_PER_MSEC); /* modifies interval value */
+
+		mutex_unlock(&data.lock);
+
+		if (msleep_interruptible(interval))
+			break;
+	}
+
+	return 0;
+}
+
+/**
+ * start_kthread - Kick off the hardware latency sampling/detector kthread
+ *
+ * This starts a kernel thread that will sit and sample the CPU timestamp
+ * counter (TSC or similar) and look for potential hardware latencies.
+ */
+static int start_kthread(void)
+{
+	kthread = kthread_run(kthread_fn, NULL,
+					DRVNAME);
+	if (IS_ERR(kthread)) {
+		pr_err(BANNER "could not start sampling thread\n");
+		enabled = 0;
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+/**
+ * stop_kthread - Inform the hardware latency samping/detector kthread to stop
+ *
+ * This kicks the running hardware latency sampling/detector kernel thread and
+ * tells it to stop sampling now. Use this on unload and at system shutdown.
+ */
+static int stop_kthread(void)
+{
+	int ret;
+
+	ret = kthread_stop(kthread);
+
+	return ret;
+}
+
+/**
+ * __reset_stats - Reset statistics for the hardware latency detector
+ *
+ * We use data to store various statistics and global state. We call this
+ * function in order to reset those when "enable" is toggled on or off, and
+ * also at initialization. Should be called with data.lock held.
+ */
+static void __reset_stats(void)
+{
+	data.count = 0;
+	data.max_sample = 0;
+	ring_buffer_reset(ring_buffer); /* flush out old sample entries */
+}
+
+/**
+ * init_stats - Setup global state statistics for the hardware latency detector
+ *
+ * We use data to store various statistics and global state. We also use
+ * a global ring buffer (ring_buffer) to keep raw samples of detected hardware
+ * induced system latencies. This function initializes these structures and
+ * allocates the global ring buffer also.
+ */
+static int init_stats(void)
+{
+	int ret = -ENOMEM;
+
+	mutex_init(&data.lock);
+	init_waitqueue_head(&data.wq);
+	atomic_set(&data.sample_open, 0);
+
+	ring_buffer = ring_buffer_alloc(buf_size, BUF_FLAGS);
+
+	if (WARN(!ring_buffer, KERN_ERR BANNER
+			       "failed to allocate ring buffer!\n"))
+		goto out;
+
+	__reset_stats();
+	data.threshold = threshold ?: DEFAULT_LAT_THRESHOLD; /* threshold us */
+	data.sample_window = DEFAULT_SAMPLE_WINDOW; /* window us */
+	data.sample_width = DEFAULT_SAMPLE_WIDTH;   /* width us */
+
+	ret = 0;
+
+out:
+	return ret;
+
+}
+
+/*
+ * simple_data_read - Wrapper read function for global state debugfs entries
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ * @entry: The entry to read from
+ *
+ * This function provides a generic read implementation for the global state
+ * "data" structure debugfs filesystem entries. It would be nice to use
+ * simple_attr_read directly, but we need to make sure that the data.lock
+ * is held during the actual read.
+ */
+static ssize_t simple_data_read(struct file *filp, char __user *ubuf,
+				size_t cnt, loff_t *ppos, const u64 *entry)
+{
+	char buf[U64STR_SIZE];
+	u64 val = 0;
+	int len = 0;
+
+	memset(buf, 0, sizeof(buf));
+
+	if (!entry)
+		return -EFAULT;
+
+	mutex_lock(&data.lock);
+	val = *entry;
+	mutex_unlock(&data.lock);
+
+	len = snprintf(buf, sizeof(buf), "%llu\n", (unsigned long long)val);
+
+	return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
+
+}
+
+/*
+ * simple_data_write - Wrapper write function for global state debugfs entries
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The userspace provided buffer to write value from
+ * @cnt: The maximum number of bytes to write
+ * @ppos: The current "file" position
+ * @entry: The entry to write to
+ *
+ * This function provides a generic write implementation for the global state
+ * "data" structure debugfs filesystem entries. It would be nice to use
+ * simple_attr_write directly, but we need to make sure that the data.lock
+ * is held during the actual write.
+ */
+static ssize_t simple_data_write(struct file *filp, const char __user *ubuf,
+				 size_t cnt, loff_t *ppos, u64 *entry)
+{
+	char buf[U64STR_SIZE];
+	int csize = min(cnt, sizeof(buf));
+	u64 val = 0;
+	int err = 0;
+
+	memset(buf, '\0', sizeof(buf));
+	if (copy_from_user(buf, ubuf, csize))
+		return -EFAULT;
+
+	buf[U64STR_SIZE-1] = '\0';			/* just in case */
+	err = kstrtoull(buf, 10, &val);
+	if (err)
+		return -EINVAL;
+
+	mutex_lock(&data.lock);
+	*entry = val;
+	mutex_unlock(&data.lock);
+
+	return csize;
+}
+
+/**
+ * debug_count_fopen - Open function for "count" debugfs entry
+ * @inode: The in-kernel inode representation of the debugfs "file"
+ * @filp: The active open file structure for the debugfs "file"
+ *
+ * This function provides an open implementation for the "count" debugfs
+ * interface to the hardware latency detector.
+ */
+static int debug_count_fopen(struct inode *inode, struct file *filp)
+{
+	return 0;
+}
+
+/**
+ * debug_count_fread - Read function for "count" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ *
+ * This function provides a read implementation for the "count" debugfs
+ * interface to the hardware latency detector. Can be used to read the
+ * number of latency readings exceeding the configured threshold since
+ * the detector was last reset (e.g. by writing a zero into "count").
+ */
+static ssize_t debug_count_fread(struct file *filp, char __user *ubuf,
+				     size_t cnt, loff_t *ppos)
+{
+	return simple_data_read(filp, ubuf, cnt, ppos, &data.count);
+}
+
+/**
+ * debug_count_fwrite - Write function for "count" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The user buffer that contains the value to write
+ * @cnt: The maximum number of bytes to write to "file"
+ * @ppos: The current position in the debugfs "file"
+ *
+ * This function provides a write implementation for the "count" debugfs
+ * interface to the hardware latency detector. Can be used to write a
+ * desired value, especially to zero the total count.
+ */
+static ssize_t  debug_count_fwrite(struct file *filp,
+				       const char __user *ubuf,
+				       size_t cnt,
+				       loff_t *ppos)
+{
+	return simple_data_write(filp, ubuf, cnt, ppos, &data.count);
+}
+
+/**
+ * debug_enable_fopen - Dummy open function for "enable" debugfs interface
+ * @inode: The in-kernel inode representation of the debugfs "file"
+ * @filp: The active open file structure for the debugfs "file"
+ *
+ * This function provides an open implementation for the "enable" debugfs
+ * interface to the hardware latency detector.
+ */
+static int debug_enable_fopen(struct inode *inode, struct file *filp)
+{
+	return 0;
+}
+
+/**
+ * debug_enable_fread - Read function for "enable" debugfs interface
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ *
+ * This function provides a read implementation for the "enable" debugfs
+ * interface to the hardware latency detector. Can be used to determine
+ * whether the detector is currently enabled ("0\n" or "1\n" returned).
+ */
+static ssize_t debug_enable_fread(struct file *filp, char __user *ubuf,
+				      size_t cnt, loff_t *ppos)
+{
+	char buf[4];
+
+	if ((cnt < sizeof(buf)) || (*ppos))
+		return 0;
+
+	buf[0] = enabled ? '1' : '0';
+	buf[1] = '\n';
+	buf[2] = '\0';
+	if (copy_to_user(ubuf, buf, strlen(buf)))
+		return -EFAULT;
+	return *ppos = strlen(buf);
+}
+
+/**
+ * debug_enable_fwrite - Write function for "enable" debugfs interface
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The user buffer that contains the value to write
+ * @cnt: The maximum number of bytes to write to "file"
+ * @ppos: The current position in the debugfs "file"
+ *
+ * This function provides a write implementation for the "enable" debugfs
+ * interface to the hardware latency detector. Can be used to enable or
+ * disable the detector, which will have the side-effect of possibly
+ * also resetting the global stats and kicking off the measuring
+ * kthread (on an enable) or the converse (upon a disable).
+ */
+static ssize_t  debug_enable_fwrite(struct file *filp,
+					const char __user *ubuf,
+					size_t cnt,
+					loff_t *ppos)
+{
+	char buf[4];
+	int csize = min(cnt, sizeof(buf));
+	long val = 0;
+	int err = 0;
+
+	memset(buf, '\0', sizeof(buf));
+	if (copy_from_user(buf, ubuf, csize))
+		return -EFAULT;
+
+	buf[sizeof(buf)-1] = '\0';			/* just in case */
+	err = kstrtoul(buf, 10, &val);
+	if (0 != err)
+		return -EINVAL;
+
+	if (val) {
+		if (enabled)
+			goto unlock;
+		enabled = 1;
+		__reset_stats();
+		if (start_kthread())
+			return -EFAULT;
+	} else {
+		if (!enabled)
+			goto unlock;
+		enabled = 0;
+		err = stop_kthread();
+		if (err) {
+			pr_err(BANNER "cannot stop kthread\n");
+			return -EFAULT;
+		}
+		wake_up(&data.wq);		/* reader(s) should return */
+	}
+unlock:
+	return csize;
+}
+
+/**
+ * debug_max_fopen - Open function for "max" debugfs entry
+ * @inode: The in-kernel inode representation of the debugfs "file"
+ * @filp: The active open file structure for the debugfs "file"
+ *
+ * This function provides an open implementation for the "max" debugfs
+ * interface to the hardware latency detector.
+ */
+static int debug_max_fopen(struct inode *inode, struct file *filp)
+{
+	return 0;
+}
+
+/**
+ * debug_max_fread - Read function for "max" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ *
+ * This function provides a read implementation for the "max" debugfs
+ * interface to the hardware latency detector. Can be used to determine
+ * the maximum latency value observed since it was last reset.
+ */
+static ssize_t debug_max_fread(struct file *filp, char __user *ubuf,
+				   size_t cnt, loff_t *ppos)
+{
+	return simple_data_read(filp, ubuf, cnt, ppos, &data.max_sample);
+}
+
+/**
+ * debug_max_fwrite - Write function for "max" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The user buffer that contains the value to write
+ * @cnt: The maximum number of bytes to write to "file"
+ * @ppos: The current position in the debugfs "file"
+ *
+ * This function provides a write implementation for the "max" debugfs
+ * interface to the hardware latency detector. Can be used to reset the
+ * maximum or set it to some other desired value - if, then, subsequent
+ * measurements exceed this value, the maximum will be updated.
+ */
+static ssize_t  debug_max_fwrite(struct file *filp,
+				     const char __user *ubuf,
+				     size_t cnt,
+				     loff_t *ppos)
+{
+	return simple_data_write(filp, ubuf, cnt, ppos, &data.max_sample);
+}
+
+
+/**
+ * debug_sample_fopen - An open function for "sample" debugfs interface
+ * @inode: The in-kernel inode representation of this debugfs "file"
+ * @filp: The active open file structure for the debugfs "file"
+ *
+ * This function handles opening the "sample" file within the hardware
+ * latency detector debugfs directory interface. This file is used to read
+ * raw samples from the global ring_buffer and allows the user to see a
+ * running latency history. Can be opened blocking or non-blocking,
+ * affecting whether it behaves as a buffer read pipe, or does not.
+ * Implements simple locking to prevent multiple simultaneous use.
+ */
+static int debug_sample_fopen(struct inode *inode, struct file *filp)
+{
+	if (!atomic_add_unless(&data.sample_open, 1, 1))
+		return -EBUSY;
+	else
+		return 0;
+}
+
+/**
+ * debug_sample_fread - A read function for "sample" debugfs interface
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The user buffer that will contain the samples read
+ * @cnt: The maximum bytes to read from the debugfs "file"
+ * @ppos: The current position in the debugfs "file"
+ *
+ * This function handles reading from the "sample" file within the hardware
+ * latency detector debugfs directory interface. This file is used to read
+ * raw samples from the global ring_buffer and allows the user to see a
+ * running latency history. By default this will block pending a new
+ * value written into the sample buffer, unless there are already a
+ * number of value(s) waiting in the buffer, or the sample file was
+ * previously opened in a non-blocking mode of operation.
+ */
+static ssize_t debug_sample_fread(struct file *filp, char __user *ubuf,
+					size_t cnt, loff_t *ppos)
+{
+	int len = 0;
+	char buf[64];
+	struct sample *sample = NULL;
+
+	if (!enabled)
+		return 0;
+
+	sample = kzalloc(sizeof(struct sample), GFP_KERNEL);
+	if (!sample)
+		return -ENOMEM;
+
+	while (!buffer_get_sample(sample)) {
+
+		DEFINE_WAIT(wait);
+
+		if (filp->f_flags & O_NONBLOCK) {
+			len = -EAGAIN;
+			goto out;
+		}
+
+		prepare_to_wait(&data.wq, &wait, TASK_INTERRUPTIBLE);
+		schedule();
+		finish_wait(&data.wq, &wait);
+
+		if (signal_pending(current)) {
+			len = -EINTR;
+			goto out;
+		}
+
+		if (!enabled) {			/* enable was toggled */
+			len = 0;
+			goto out;
+		}
+	}
+
+	len = snprintf(buf, sizeof(buf), "%010lu.%010lu\t%llu\t%llu\n",
+		       sample->timestamp.tv_sec,
+		       sample->timestamp.tv_nsec,
+		       sample->duration,
+		       sample->outer_duration);
+
+
+	/* handling partial reads is more trouble than it's worth */
+	if (len > cnt)
+		goto out;
+
+	if (copy_to_user(ubuf, buf, len))
+		len = -EFAULT;
+
+out:
+	kfree(sample);
+	return len;
+}
+
+/**
+ * debug_sample_release - Release function for "sample" debugfs interface
+ * @inode: The in-kernel inode represenation of the debugfs "file"
+ * @filp: The active open file structure for the debugfs "file"
+ *
+ * This function completes the close of the debugfs interface "sample" file.
+ * Frees the sample_open "lock" so that other users may open the interface.
+ */
+static int debug_sample_release(struct inode *inode, struct file *filp)
+{
+	atomic_dec(&data.sample_open);
+
+	return 0;
+}
+
+/**
+ * debug_threshold_fopen - Open function for "threshold" debugfs entry
+ * @inode: The in-kernel inode representation of the debugfs "file"
+ * @filp: The active open file structure for the debugfs "file"
+ *
+ * This function provides an open implementation for the "threshold" debugfs
+ * interface to the hardware latency detector.
+ */
+static int debug_threshold_fopen(struct inode *inode, struct file *filp)
+{
+	return 0;
+}
+
+/**
+ * debug_threshold_fread - Read function for "threshold" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ *
+ * This function provides a read implementation for the "threshold" debugfs
+ * interface to the hardware latency detector. It can be used to determine
+ * the current threshold level at which a latency will be recorded in the
+ * global ring buffer, typically on the order of 10us.
+ */
+static ssize_t debug_threshold_fread(struct file *filp, char __user *ubuf,
+					 size_t cnt, loff_t *ppos)
+{
+	return simple_data_read(filp, ubuf, cnt, ppos, &data.threshold);
+}
+
+/**
+ * debug_threshold_fwrite - Write function for "threshold" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The user buffer that contains the value to write
+ * @cnt: The maximum number of bytes to write to "file"
+ * @ppos: The current position in the debugfs "file"
+ *
+ * This function provides a write implementation for the "threshold" debugfs
+ * interface to the hardware latency detector. It can be used to configure
+ * the threshold level at which any subsequently detected latencies will
+ * be recorded into the global ring buffer.
+ */
+static ssize_t  debug_threshold_fwrite(struct file *filp,
+					const char __user *ubuf,
+					size_t cnt,
+					loff_t *ppos)
+{
+	int ret;
+
+	ret = simple_data_write(filp, ubuf, cnt, ppos, &data.threshold);
+
+	if (enabled)
+		wake_up_process(kthread);
+
+	return ret;
+}
+
+/**
+ * debug_width_fopen - Open function for "width" debugfs entry
+ * @inode: The in-kernel inode representation of the debugfs "file"
+ * @filp: The active open file structure for the debugfs "file"
+ *
+ * This function provides an open implementation for the "width" debugfs
+ * interface to the hardware latency detector.
+ */
+static int debug_width_fopen(struct inode *inode, struct file *filp)
+{
+	return 0;
+}
+
+/**
+ * debug_width_fread - Read function for "width" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ *
+ * This function provides a read implementation for the "width" debugfs
+ * interface to the hardware latency detector. It can be used to determine
+ * for how many us of the total window us we will actively sample for any
+ * hardware-induced latecy periods. Obviously, it is not possible to
+ * sample constantly and have the system respond to a sample reader, or,
+ * worse, without having the system appear to have gone out to lunch.
+ */
+static ssize_t debug_width_fread(struct file *filp, char __user *ubuf,
+				     size_t cnt, loff_t *ppos)
+{
+	return simple_data_read(filp, ubuf, cnt, ppos, &data.sample_width);
+}
+
+/**
+ * debug_width_fwrite - Write function for "width" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The user buffer that contains the value to write
+ * @cnt: The maximum number of bytes to write to "file"
+ * @ppos: The current position in the debugfs "file"
+ *
+ * This function provides a write implementation for the "width" debugfs
+ * interface to the hardware latency detector. It can be used to configure
+ * for how many us of the total window us we will actively sample for any
+ * hardware-induced latency periods. Obviously, it is not possible to
+ * sample constantly and have the system respond to a sample reader, or,
+ * worse, without having the system appear to have gone out to lunch. It
+ * is enforced that width is less that the total window size.
+ */
+static ssize_t  debug_width_fwrite(struct file *filp,
+				       const char __user *ubuf,
+				       size_t cnt,
+				       loff_t *ppos)
+{
+	char buf[U64STR_SIZE];
+	int csize = min(cnt, sizeof(buf));
+	u64 val = 0;
+	int err = 0;
+
+	memset(buf, '\0', sizeof(buf));
+	if (copy_from_user(buf, ubuf, csize))
+		return -EFAULT;
+
+	buf[U64STR_SIZE-1] = '\0';			/* just in case */
+	err = kstrtoull(buf, 10, &val);
+	if (0 != err)
+		return -EINVAL;
+
+	mutex_lock(&data.lock);
+	if (val < data.sample_window)
+		data.sample_width = val;
+	else {
+		mutex_unlock(&data.lock);
+		return -EINVAL;
+	}
+	mutex_unlock(&data.lock);
+
+	if (enabled)
+		wake_up_process(kthread);
+
+	return csize;
+}
+
+/**
+ * debug_window_fopen - Open function for "window" debugfs entry
+ * @inode: The in-kernel inode representation of the debugfs "file"
+ * @filp: The active open file structure for the debugfs "file"
+ *
+ * This function provides an open implementation for the "window" debugfs
+ * interface to the hardware latency detector. The window is the total time
+ * in us that will be considered one sample period. Conceptually, windows
+ * occur back-to-back and contain a sample width period during which
+ * actual sampling occurs.
+ */
+static int debug_window_fopen(struct inode *inode, struct file *filp)
+{
+	return 0;
+}
+
+/**
+ * debug_window_fread - Read function for "window" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ *
+ * This function provides a read implementation for the "window" debugfs
+ * interface to the hardware latency detector. The window is the total time
+ * in us that will be considered one sample period. Conceptually, windows
+ * occur back-to-back and contain a sample width period during which
+ * actual sampling occurs. Can be used to read the total window size.
+ */
+static ssize_t debug_window_fread(struct file *filp, char __user *ubuf,
+				      size_t cnt, loff_t *ppos)
+{
+	return simple_data_read(filp, ubuf, cnt, ppos, &data.sample_window);
+}
+
+/**
+ * debug_window_fwrite - Write function for "window" debugfs entry
+ * @filp: The active open file structure for the debugfs "file"
+ * @ubuf: The user buffer that contains the value to write
+ * @cnt: The maximum number of bytes to write to "file"
+ * @ppos: The current position in the debugfs "file"
+ *
+ * This function provides a write implementation for the "window" debufds
+ * interface to the hardware latency detetector. The window is the total time
+ * in us that will be considered one sample period. Conceptually, windows
+ * occur back-to-back and contain a sample width period during which
+ * actual sampling occurs. Can be used to write a new total window size. It
+ * is enfoced that any value written must be greater than the sample width
+ * size, or an error results.
+ */
+static ssize_t  debug_window_fwrite(struct file *filp,
+					const char __user *ubuf,
+					size_t cnt,
+					loff_t *ppos)
+{
+	char buf[U64STR_SIZE];
+	int csize = min(cnt, sizeof(buf));
+	u64 val = 0;
+	int err = 0;
+
+	memset(buf, '\0', sizeof(buf));
+	if (copy_from_user(buf, ubuf, csize))
+		return -EFAULT;
+
+	buf[U64STR_SIZE-1] = '\0';			/* just in case */
+	err = kstrtoull(buf, 10, &val);
+	if (0 != err)
+		return -EINVAL;
+
+	mutex_lock(&data.lock);
+	if (data.sample_width < val)
+		data.sample_window = val;
+	else {
+		mutex_unlock(&data.lock);
+		return -EINVAL;
+	}
+	mutex_unlock(&data.lock);
+
+	return csize;
+}
+
+/*
+ * Function pointers for the "count" debugfs file operations
+ */
+static const struct file_operations count_fops = {
+	.open		= debug_count_fopen,
+	.read		= debug_count_fread,
+	.write		= debug_count_fwrite,
+	.owner		= THIS_MODULE,
+};
+
+/*
+ * Function pointers for the "enable" debugfs file operations
+ */
+static const struct file_operations enable_fops = {
+	.open		= debug_enable_fopen,
+	.read		= debug_enable_fread,
+	.write		= debug_enable_fwrite,
+	.owner		= THIS_MODULE,
+};
+
+/*
+ * Function pointers for the "max" debugfs file operations
+ */
+static const struct file_operations max_fops = {
+	.open		= debug_max_fopen,
+	.read		= debug_max_fread,
+	.write		= debug_max_fwrite,
+	.owner		= THIS_MODULE,
+};
+
+/*
+ * Function pointers for the "sample" debugfs file operations
+ */
+static const struct file_operations sample_fops = {
+	.open		= debug_sample_fopen,
+	.read		= debug_sample_fread,
+	.release	= debug_sample_release,
+	.owner		= THIS_MODULE,
+};
+
+/*
+ * Function pointers for the "threshold" debugfs file operations
+ */
+static const struct file_operations threshold_fops = {
+	.open		= debug_threshold_fopen,
+	.read		= debug_threshold_fread,
+	.write		= debug_threshold_fwrite,
+	.owner		= THIS_MODULE,
+};
+
+/*
+ * Function pointers for the "width" debugfs file operations
+ */
+static const struct file_operations width_fops = {
+	.open		= debug_width_fopen,
+	.read		= debug_width_fread,
+	.write		= debug_width_fwrite,
+	.owner		= THIS_MODULE,
+};
+
+/*
+ * Function pointers for the "window" debugfs file operations
+ */
+static const struct file_operations window_fops = {
+	.open		= debug_window_fopen,
+	.read		= debug_window_fread,
+	.write		= debug_window_fwrite,
+	.owner		= THIS_MODULE,
+};
+
+/**
+ * init_debugfs - A function to initialize the debugfs interface files
+ *
+ * This function creates entries in debugfs for "hwlat_detector", including
+ * files to read values from the detector, current samples, and the
+ * maximum sample that has been captured since the hardware latency
+ * dectector was started.
+ */
+static int init_debugfs(void)
+{
+	int ret = -ENOMEM;
+
+	debug_dir = debugfs_create_dir(DRVNAME, NULL);
+	if (!debug_dir)
+		goto err_debug_dir;
+
+	debug_sample = debugfs_create_file("sample", 0444,
+					       debug_dir, NULL,
+					       &sample_fops);
+	if (!debug_sample)
+		goto err_sample;
+
+	debug_count = debugfs_create_file("count", 0444,
+					      debug_dir, NULL,
+					      &count_fops);
+	if (!debug_count)
+		goto err_count;
+
+	debug_max = debugfs_create_file("max", 0444,
+					    debug_dir, NULL,
+					    &max_fops);
+	if (!debug_max)
+		goto err_max;
+
+	debug_sample_window = debugfs_create_file("window", 0644,
+						      debug_dir, NULL,
+						      &window_fops);
+	if (!debug_sample_window)
+		goto err_window;
+
+	debug_sample_width = debugfs_create_file("width", 0644,
+						     debug_dir, NULL,
+						     &width_fops);
+	if (!debug_sample_width)
+		goto err_width;
+
+	debug_threshold = debugfs_create_file("threshold", 0644,
+						  debug_dir, NULL,
+						  &threshold_fops);
+	if (!debug_threshold)
+		goto err_threshold;
+
+	debug_enable = debugfs_create_file("enable", 0644,
+					       debug_dir, &enabled,
+					       &enable_fops);
+	if (!debug_enable)
+		goto err_enable;
+
+	else {
+		ret = 0;
+		goto out;
+	}
+
+err_enable:
+	debugfs_remove(debug_threshold);
+err_threshold:
+	debugfs_remove(debug_sample_width);
+err_width:
+	debugfs_remove(debug_sample_window);
+err_window:
+	debugfs_remove(debug_max);
+err_max:
+	debugfs_remove(debug_count);
+err_count:
+	debugfs_remove(debug_sample);
+err_sample:
+	debugfs_remove(debug_dir);
+err_debug_dir:
+out:
+	return ret;
+}
+
+/**
+ * free_debugfs - A function to cleanup the debugfs file interface
+ */
+static void free_debugfs(void)
+{
+	/* could also use a debugfs_remove_recursive */
+	debugfs_remove(debug_enable);
+	debugfs_remove(debug_threshold);
+	debugfs_remove(debug_sample_width);
+	debugfs_remove(debug_sample_window);
+	debugfs_remove(debug_max);
+	debugfs_remove(debug_count);
+	debugfs_remove(debug_sample);
+	debugfs_remove(debug_dir);
+}
+
+/**
+ * detector_init - Standard module initialization code
+ */
+static int detector_init(void)
+{
+	int ret = -ENOMEM;
+
+	pr_info(BANNER "version %s\n", VERSION);
+
+	ret = init_stats();
+	if (0 != ret)
+		goto out;
+
+	ret = init_debugfs();
+	if (0 != ret)
+		goto err_stats;
+
+	if (enabled)
+		ret = start_kthread();
+
+	goto out;
+
+err_stats:
+	ring_buffer_free(ring_buffer);
+out:
+	return ret;
+
+}
+
+/**
+ * detector_exit - Standard module cleanup code
+ */
+static void detector_exit(void)
+{
+	int err;
+
+	if (enabled) {
+		enabled = 0;
+		err = stop_kthread();
+		if (err)
+			pr_err(BANNER "cannot stop kthread\n");
+	}
+
+	free_debugfs();
+	ring_buffer_free(ring_buffer);	/* free up the ring buffer */
+
+}
+
+module_init(detector_init);
+module_exit(detector_exit);
diff -Nur linux-3.18.12.orig/drivers/misc/Kconfig linux-3.18.12/drivers/misc/Kconfig
--- linux-3.18.12.orig/drivers/misc/Kconfig	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/misc/Kconfig	2015-04-26 13:32:22.395684003 -0500
@@ -54,6 +54,7 @@
 config ATMEL_TCLIB
 	bool "Atmel AT32/AT91 Timer/Counter Library"
 	depends on (AVR32 || ARCH_AT91)
+	default y if PREEMPT_RT_FULL
 	help
 	  Select this if you want a library to allocate the Timer/Counter
 	  blocks found on many Atmel processors.  This facilitates using
@@ -69,8 +70,7 @@
 	  are combined to make a single 32-bit timer.
 
 	  When GENERIC_CLOCKEVENTS is defined, the third timer channel
-	  may be used as a clock event device supporting oneshot mode
-	  (delays of up to two seconds) based on the 32 KiHz clock.
+	  may be used as a clock event device supporting oneshot mode.
 
 config ATMEL_TCB_CLKSRC_BLOCK
 	int
@@ -84,6 +84,15 @@
 	  TC can be used for other purposes, such as PWM generation and
 	  interval timing.
 
+config ATMEL_TCB_CLKSRC_USE_SLOW_CLOCK
+	bool "TC Block use 32 KiHz clock"
+	depends on ATMEL_TCB_CLKSRC
+	default y if !PREEMPT_RT_FULL
+	help
+	  Select this to use 32 KiHz base clock rate as TC block clock
+	  source for clock events.
+
+
 config DUMMY_IRQ
 	tristate "Dummy IRQ handler"
 	default n
@@ -113,6 +122,35 @@
 	  for information on the specific driver level and support statement
 	  for your IBM server.
 
+config HWLAT_DETECTOR
+	tristate "Testing module to detect hardware-induced latencies"
+	depends on DEBUG_FS
+	depends on RING_BUFFER
+	default m
+	---help---
+	  A simple hardware latency detector. Use this module to detect
+	  large latencies introduced by the behavior of the underlying
+	  system firmware external to Linux. We do this using periodic
+	  use of stop_machine to grab all available CPUs and measure
+	  for unexplainable gaps in the CPU timestamp counter(s). By
+	  default, the module is not enabled until the "enable" file
+	  within the "hwlat_detector" debugfs directory is toggled.
+
+	  This module is often used to detect SMI (System Management
+	  Interrupts) on x86 systems, though is not x86 specific. To
+	  this end, we default to using a sample window of 1 second,
+	  during which we will sample for 0.5 seconds. If an SMI or
+	  similar event occurs during that time, it is recorded
+	  into an 8K samples global ring buffer until retreived.
+
+	  WARNING: This software should never be enabled (it can be built
+	  but should not be turned on after it is loaded) in a production
+	  environment where high latencies are a concern since the
+	  sampling mechanism actually introduces latencies for
+	  regular tasks while the CPU(s) are being held.
+
+	  If unsure, say N
+
 config PHANTOM
 	tristate "Sensable PHANToM (PCI)"
 	depends on PCI
diff -Nur linux-3.18.12.orig/drivers/misc/Makefile linux-3.18.12/drivers/misc/Makefile
--- linux-3.18.12.orig/drivers/misc/Makefile	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/misc/Makefile	2015-04-26 13:32:22.395684003 -0500
@@ -38,6 +38,7 @@
 obj-$(CONFIG_HMC6352)		+= hmc6352.o
 obj-y				+= eeprom/
 obj-y				+= cb710/
+obj-$(CONFIG_HWLAT_DETECTOR)	+= hwlat_detector.o
 obj-$(CONFIG_SPEAR13XX_PCIE_GADGET)	+= spear13xx_pcie_gadget.o
 obj-$(CONFIG_VMWARE_BALLOON)	+= vmw_balloon.o
 obj-$(CONFIG_ARM_CHARLCD)	+= arm-charlcd.o
diff -Nur linux-3.18.12.orig/drivers/mmc/host/mmci.c linux-3.18.12/drivers/mmc/host/mmci.c
--- linux-3.18.12.orig/drivers/mmc/host/mmci.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/mmc/host/mmci.c	2015-04-26 13:32:22.395684003 -0500
@@ -1153,15 +1153,12 @@
 	struct sg_mapping_iter *sg_miter = &host->sg_miter;
 	struct variant_data *variant = host->variant;
 	void __iomem *base = host->base;
-	unsigned long flags;
 	u32 status;
 
 	status = readl(base + MMCISTATUS);
 
 	dev_dbg(mmc_dev(host->mmc), "irq1 (pio) %08x\n", status);
 
-	local_irq_save(flags);
-
 	do {
 		unsigned int remain, len;
 		char *buffer;
@@ -1201,8 +1198,6 @@
 
 	sg_miter_stop(sg_miter);
 
-	local_irq_restore(flags);
-
 	/*
 	 * If we have less than the fifo 'half-full' threshold to transfer,
 	 * trigger a PIO interrupt as soon as any data is available.
diff -Nur linux-3.18.12.orig/drivers/mmc/host/sdhci.c linux-3.18.12/drivers/mmc/host/sdhci.c
--- linux-3.18.12.orig/drivers/mmc/host/sdhci.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/mmc/host/sdhci.c	2015-04-26 13:32:22.399684003 -0500
@@ -2565,6 +2565,31 @@
 	return isr ? IRQ_HANDLED : IRQ_NONE;
 }
 
+#ifdef CONFIG_PREEMPT_RT_BASE
+static irqreturn_t sdhci_rt_irq(int irq, void *dev_id)
+{
+	irqreturn_t ret;
+
+	local_bh_disable();
+	ret = sdhci_irq(irq, dev_id);
+	local_bh_enable();
+	if (ret == IRQ_WAKE_THREAD)
+		ret = sdhci_thread_irq(irq, dev_id);
+	return ret;
+}
+#endif
+
+static int sdhci_req_irq(struct sdhci_host *host)
+{
+#ifdef CONFIG_PREEMPT_RT_BASE
+	return request_threaded_irq(host->irq, NULL, sdhci_rt_irq,
+				    IRQF_SHARED, mmc_hostname(host->mmc), host);
+#else
+	return request_threaded_irq(host->irq, sdhci_irq, sdhci_thread_irq,
+				    IRQF_SHARED, mmc_hostname(host->mmc), host);
+#endif
+}
+
 /*****************************************************************************\
  *                                                                           *
  * Suspend/resume                                                            *
@@ -2632,9 +2657,7 @@
 	}
 
 	if (!device_may_wakeup(mmc_dev(host->mmc))) {
-		ret = request_threaded_irq(host->irq, sdhci_irq,
-					   sdhci_thread_irq, IRQF_SHARED,
-					   mmc_hostname(host->mmc), host);
+		ret = sdhci_req_irq(host);
 		if (ret)
 			return ret;
 	} else {
@@ -3253,8 +3276,7 @@
 
 	sdhci_init(host, 0);
 
-	ret = request_threaded_irq(host->irq, sdhci_irq, sdhci_thread_irq,
-				   IRQF_SHARED,	mmc_hostname(mmc), host);
+	ret = sdhci_req_irq(host);
 	if (ret) {
 		pr_err("%s: Failed to request IRQ %d: %d\n",
 		       mmc_hostname(mmc), host->irq, ret);
diff -Nur linux-3.18.12.orig/drivers/net/ethernet/3com/3c59x.c linux-3.18.12/drivers/net/ethernet/3com/3c59x.c
--- linux-3.18.12.orig/drivers/net/ethernet/3com/3c59x.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/net/ethernet/3com/3c59x.c	2015-04-26 13:32:22.399684003 -0500
@@ -842,9 +842,9 @@
 {
 	struct vortex_private *vp = netdev_priv(dev);
 	unsigned long flags;
-	local_irq_save(flags);
+	local_irq_save_nort(flags);
 	(vp->full_bus_master_rx ? boomerang_interrupt:vortex_interrupt)(dev->irq,dev);
-	local_irq_restore(flags);
+	local_irq_restore_nort(flags);
 }
 #endif
 
@@ -1916,12 +1916,12 @@
 			 * Block interrupts because vortex_interrupt does a bare spin_lock()
 			 */
 			unsigned long flags;
-			local_irq_save(flags);
+			local_irq_save_nort(flags);
 			if (vp->full_bus_master_tx)
 				boomerang_interrupt(dev->irq, dev);
 			else
 				vortex_interrupt(dev->irq, dev);
-			local_irq_restore(flags);
+			local_irq_restore_nort(flags);
 		}
 	}
 
diff -Nur linux-3.18.12.orig/drivers/net/ethernet/atheros/atl1c/atl1c_main.c linux-3.18.12/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
--- linux-3.18.12.orig/drivers/net/ethernet/atheros/atl1c/atl1c_main.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/net/ethernet/atheros/atl1c/atl1c_main.c	2015-04-26 13:32:22.399684003 -0500
@@ -2213,11 +2213,7 @@
 	}
 
 	tpd_req = atl1c_cal_tpd_req(skb);
-	if (!spin_trylock_irqsave(&adapter->tx_lock, flags)) {
-		if (netif_msg_pktdata(adapter))
-			dev_info(&adapter->pdev->dev, "tx locked\n");
-		return NETDEV_TX_LOCKED;
-	}
+	spin_lock_irqsave(&adapter->tx_lock, flags);
 
 	if (atl1c_tpd_avail(adapter, type) < tpd_req) {
 		/* no enough descriptor, just stop queue */
diff -Nur linux-3.18.12.orig/drivers/net/ethernet/atheros/atl1e/atl1e_main.c linux-3.18.12/drivers/net/ethernet/atheros/atl1e/atl1e_main.c
--- linux-3.18.12.orig/drivers/net/ethernet/atheros/atl1e/atl1e_main.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/net/ethernet/atheros/atl1e/atl1e_main.c	2015-04-26 13:32:22.399684003 -0500
@@ -1880,8 +1880,7 @@
 		return NETDEV_TX_OK;
 	}
 	tpd_req = atl1e_cal_tdp_req(skb);
-	if (!spin_trylock_irqsave(&adapter->tx_lock, flags))
-		return NETDEV_TX_LOCKED;
+	spin_lock_irqsave(&adapter->tx_lock, flags);
 
 	if (atl1e_tpd_avail(adapter) < tpd_req) {
 		/* no enough descriptor, just stop queue */
diff -Nur linux-3.18.12.orig/drivers/net/ethernet/chelsio/cxgb/sge.c linux-3.18.12/drivers/net/ethernet/chelsio/cxgb/sge.c
--- linux-3.18.12.orig/drivers/net/ethernet/chelsio/cxgb/sge.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/net/ethernet/chelsio/cxgb/sge.c	2015-04-26 13:32:22.399684003 -0500
@@ -1663,8 +1663,7 @@
 	struct cmdQ *q = &sge->cmdQ[qid];
 	unsigned int credits, pidx, genbit, count, use_sched_skb = 0;
 
-	if (!spin_trylock(&q->lock))
-		return NETDEV_TX_LOCKED;
+	spin_lock(&q->lock);
 
 	reclaim_completed_tx(sge, q);
 
diff -Nur linux-3.18.12.orig/drivers/net/ethernet/freescale/gianfar.c linux-3.18.12/drivers/net/ethernet/freescale/gianfar.c
--- linux-3.18.12.orig/drivers/net/ethernet/freescale/gianfar.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/net/ethernet/freescale/gianfar.c	2015-04-26 13:32:22.399684003 -0500
@@ -1483,7 +1483,7 @@
 
 	if (netif_running(ndev)) {
 
-		local_irq_save(flags);
+		local_irq_save_nort(flags);
 		lock_tx_qs(priv);
 
 		gfar_halt_nodisable(priv);
@@ -1499,7 +1499,7 @@
 		gfar_write(&regs->maccfg1, tempval);
 
 		unlock_tx_qs(priv);
-		local_irq_restore(flags);
+		local_irq_restore_nort(flags);
 
 		disable_napi(priv);
 
@@ -1541,7 +1541,7 @@
 	/* Disable Magic Packet mode, in case something
 	 * else woke us up.
 	 */
-	local_irq_save(flags);
+	local_irq_save_nort(flags);
 	lock_tx_qs(priv);
 
 	tempval = gfar_read(&regs->maccfg2);
@@ -1551,7 +1551,7 @@
 	gfar_start(priv);
 
 	unlock_tx_qs(priv);
-	local_irq_restore(flags);
+	local_irq_restore_nort(flags);
 
 	netif_device_attach(ndev);
 
@@ -3307,14 +3307,14 @@
 			dev->stats.tx_dropped++;
 			atomic64_inc(&priv->extra_stats.tx_underrun);
 
-			local_irq_save(flags);
+			local_irq_save_nort(flags);
 			lock_tx_qs(priv);
 
 			/* Reactivate the Tx Queues */
 			gfar_write(&regs->tstat, gfargrp->tstat);
 
 			unlock_tx_qs(priv);
-			local_irq_restore(flags);
+			local_irq_restore_nort(flags);
 		}
 		netif_dbg(priv, tx_err, dev, "Transmit Error\n");
 	}
diff -Nur linux-3.18.12.orig/drivers/net/ethernet/neterion/s2io.c linux-3.18.12/drivers/net/ethernet/neterion/s2io.c
--- linux-3.18.12.orig/drivers/net/ethernet/neterion/s2io.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/net/ethernet/neterion/s2io.c	2015-04-26 13:32:22.403684003 -0500
@@ -4084,12 +4084,7 @@
 			[skb->priority & (MAX_TX_FIFOS - 1)];
 	fifo = &mac_control->fifos[queue];
 
-	if (do_spin_lock)
-		spin_lock_irqsave(&fifo->tx_lock, flags);
-	else {
-		if (unlikely(!spin_trylock_irqsave(&fifo->tx_lock, flags)))
-			return NETDEV_TX_LOCKED;
-	}
+	spin_lock_irqsave(&fifo->tx_lock, flags);
 
 	if (sp->config.multiq) {
 		if (__netif_subqueue_stopped(dev, fifo->fifo_no)) {
diff -Nur linux-3.18.12.orig/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c linux-3.18.12/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c
--- linux-3.18.12.orig/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe_main.c	2015-04-26 13:32:22.403684003 -0500
@@ -2137,10 +2137,8 @@
 	struct pch_gbe_tx_ring *tx_ring = adapter->tx_ring;
 	unsigned long flags;
 
-	if (!spin_trylock_irqsave(&tx_ring->tx_lock, flags)) {
-		/* Collision - tell upper layer to requeue */
-		return NETDEV_TX_LOCKED;
-	}
+	spin_lock_irqsave(&tx_ring->tx_lock, flags);
+
 	if (unlikely(!PCH_GBE_DESC_UNUSED(tx_ring))) {
 		netif_stop_queue(netdev);
 		spin_unlock_irqrestore(&tx_ring->tx_lock, flags);
diff -Nur linux-3.18.12.orig/drivers/net/ethernet/realtek/8139too.c linux-3.18.12/drivers/net/ethernet/realtek/8139too.c
--- linux-3.18.12.orig/drivers/net/ethernet/realtek/8139too.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/net/ethernet/realtek/8139too.c	2015-04-26 13:32:22.403684003 -0500
@@ -2215,7 +2215,7 @@
 	struct rtl8139_private *tp = netdev_priv(dev);
 	const int irq = tp->pci_dev->irq;
 
-	disable_irq(irq);
+	disable_irq_nosync(irq);
 	rtl8139_interrupt(irq, dev);
 	enable_irq(irq);
 }
diff -Nur linux-3.18.12.orig/drivers/net/ethernet/tehuti/tehuti.c linux-3.18.12/drivers/net/ethernet/tehuti/tehuti.c
--- linux-3.18.12.orig/drivers/net/ethernet/tehuti/tehuti.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/net/ethernet/tehuti/tehuti.c	2015-04-26 13:32:22.403684003 -0500
@@ -1629,13 +1629,8 @@
 	unsigned long flags;
 
 	ENTER;
-	local_irq_save(flags);
-	if (!spin_trylock(&priv->tx_lock)) {
-		local_irq_restore(flags);
-		DBG("%s[%s]: TX locked, returning NETDEV_TX_LOCKED\n",
-		    BDX_DRV_NAME, ndev->name);
-		return NETDEV_TX_LOCKED;
-	}
+
+	spin_lock_irqsave(&priv->tx_lock, flags);
 
 	/* build tx descriptor */
 	BDX_ASSERT(f->m.wptr >= f->m.memsz);	/* started with valid wptr */
diff -Nur linux-3.18.12.orig/drivers/net/rionet.c linux-3.18.12/drivers/net/rionet.c
--- linux-3.18.12.orig/drivers/net/rionet.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/net/rionet.c	2015-04-26 13:32:22.403684003 -0500
@@ -174,11 +174,7 @@
 	unsigned long flags;
 	int add_num = 1;
 
-	local_irq_save(flags);
-	if (!spin_trylock(&rnet->tx_lock)) {
-		local_irq_restore(flags);
-		return NETDEV_TX_LOCKED;
-	}
+	spin_lock_irqsave(&rnet->tx_lock, flags);
 
 	if (is_multicast_ether_addr(eth->h_dest))
 		add_num = nets[rnet->mport->id].nact;
diff -Nur linux-3.18.12.orig/drivers/net/wireless/orinoco/orinoco_usb.c linux-3.18.12/drivers/net/wireless/orinoco/orinoco_usb.c
--- linux-3.18.12.orig/drivers/net/wireless/orinoco/orinoco_usb.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/net/wireless/orinoco/orinoco_usb.c	2015-04-26 13:32:22.403684003 -0500
@@ -699,7 +699,7 @@
 			while (!ctx->done.done && msecs--)
 				udelay(1000);
 		} else {
-			wait_event_interruptible(ctx->done.wait,
+			swait_event_interruptible(ctx->done.wait,
 						 ctx->done.done);
 		}
 		break;
diff -Nur linux-3.18.12.orig/drivers/pci/access.c linux-3.18.12/drivers/pci/access.c
--- linux-3.18.12.orig/drivers/pci/access.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/pci/access.c	2015-04-26 13:32:22.403684003 -0500
@@ -434,7 +434,7 @@
 	WARN_ON(!dev->block_cfg_access);
 
 	dev->block_cfg_access = 0;
-	wake_up_all(&pci_cfg_wait);
+	wake_up_all_locked(&pci_cfg_wait);
 	raw_spin_unlock_irqrestore(&pci_lock, flags);
 }
 EXPORT_SYMBOL_GPL(pci_cfg_access_unlock);
diff -Nur linux-3.18.12.orig/drivers/scsi/fcoe/fcoe.c linux-3.18.12/drivers/scsi/fcoe/fcoe.c
--- linux-3.18.12.orig/drivers/scsi/fcoe/fcoe.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/scsi/fcoe/fcoe.c	2015-04-26 13:32:22.403684003 -0500
@@ -1286,7 +1286,7 @@
 	struct sk_buff *skb;
 #ifdef CONFIG_SMP
 	struct fcoe_percpu_s *p0;
-	unsigned targ_cpu = get_cpu();
+	unsigned targ_cpu = get_cpu_light();
 #endif /* CONFIG_SMP */
 
 	FCOE_DBG("Destroying receive thread for CPU %d\n", cpu);
@@ -1342,7 +1342,7 @@
 			kfree_skb(skb);
 		spin_unlock_bh(&p->fcoe_rx_list.lock);
 	}
-	put_cpu();
+	put_cpu_light();
 #else
 	/*
 	 * This a non-SMP scenario where the singular Rx thread is
@@ -1566,11 +1566,11 @@
 static int fcoe_alloc_paged_crc_eof(struct sk_buff *skb, int tlen)
 {
 	struct fcoe_percpu_s *fps;
-	int rc;
+	int rc, cpu = get_cpu_light();
 
-	fps = &get_cpu_var(fcoe_percpu);
+	fps = &per_cpu(fcoe_percpu, cpu);
 	rc = fcoe_get_paged_crc_eof(skb, tlen, fps);
-	put_cpu_var(fcoe_percpu);
+	put_cpu_light();
 
 	return rc;
 }
@@ -1768,11 +1768,11 @@
 		return 0;
 	}
 
-	stats = per_cpu_ptr(lport->stats, get_cpu());
+	stats = per_cpu_ptr(lport->stats, get_cpu_light());
 	stats->InvalidCRCCount++;
 	if (stats->InvalidCRCCount < 5)
 		printk(KERN_WARNING "fcoe: dropping frame with CRC error\n");
-	put_cpu();
+	put_cpu_light();
 	return -EINVAL;
 }
 
@@ -1848,13 +1848,13 @@
 		goto drop;
 
 	if (!fcoe_filter_frames(lport, fp)) {
-		put_cpu();
+		put_cpu_light();
 		fc_exch_recv(lport, fp);
 		return;
 	}
 drop:
 	stats->ErrorFrames++;
-	put_cpu();
+	put_cpu_light();
 	kfree_skb(skb);
 }
 
diff -Nur linux-3.18.12.orig/drivers/scsi/fcoe/fcoe_ctlr.c linux-3.18.12/drivers/scsi/fcoe/fcoe_ctlr.c
--- linux-3.18.12.orig/drivers/scsi/fcoe/fcoe_ctlr.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/scsi/fcoe/fcoe_ctlr.c	2015-04-26 13:32:22.403684003 -0500
@@ -831,7 +831,7 @@
 
 	INIT_LIST_HEAD(&del_list);
 
-	stats = per_cpu_ptr(fip->lp->stats, get_cpu());
+	stats = per_cpu_ptr(fip->lp->stats, get_cpu_light());
 
 	list_for_each_entry_safe(fcf, next, &fip->fcfs, list) {
 		deadline = fcf->time + fcf->fka_period + fcf->fka_period / 2;
@@ -867,7 +867,7 @@
 				sel_time = fcf->time;
 		}
 	}
-	put_cpu();
+	put_cpu_light();
 
 	list_for_each_entry_safe(fcf, next, &del_list, list) {
 		/* Removes fcf from current list */
diff -Nur linux-3.18.12.orig/drivers/scsi/libfc/fc_exch.c linux-3.18.12/drivers/scsi/libfc/fc_exch.c
--- linux-3.18.12.orig/drivers/scsi/libfc/fc_exch.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/scsi/libfc/fc_exch.c	2015-04-26 13:32:22.403684003 -0500
@@ -816,10 +816,10 @@
 	}
 	memset(ep, 0, sizeof(*ep));
 
-	cpu = get_cpu();
+	cpu = get_cpu_light();
 	pool = per_cpu_ptr(mp->pool, cpu);
 	spin_lock_bh(&pool->lock);
-	put_cpu();
+	put_cpu_light();
 
 	/* peek cache of free slot */
 	if (pool->left != FC_XID_UNKNOWN) {
diff -Nur linux-3.18.12.orig/drivers/scsi/libsas/sas_ata.c linux-3.18.12/drivers/scsi/libsas/sas_ata.c
--- linux-3.18.12.orig/drivers/scsi/libsas/sas_ata.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/scsi/libsas/sas_ata.c	2015-04-26 13:32:22.407684003 -0500
@@ -191,7 +191,7 @@
 	/* TODO: audit callers to ensure they are ready for qc_issue to
 	 * unconditionally re-enable interrupts
 	 */
-	local_irq_save(flags);
+	local_irq_save_nort(flags);
 	spin_unlock(ap->lock);
 
 	/* If the device fell off, no sense in issuing commands */
@@ -261,7 +261,7 @@
 
  out:
 	spin_lock(ap->lock);
-	local_irq_restore(flags);
+	local_irq_restore_nort(flags);
 	return ret;
 }
 
diff -Nur linux-3.18.12.orig/drivers/scsi/qla2xxx/qla_inline.h linux-3.18.12/drivers/scsi/qla2xxx/qla_inline.h
--- linux-3.18.12.orig/drivers/scsi/qla2xxx/qla_inline.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/scsi/qla2xxx/qla_inline.h	2015-04-26 13:32:22.407684003 -0500
@@ -59,12 +59,12 @@
 {
 	unsigned long flags;
 	struct qla_hw_data *ha = rsp->hw;
-	local_irq_save(flags);
+	local_irq_save_nort(flags);
 	if (IS_P3P_TYPE(ha))
 		qla82xx_poll(0, rsp);
 	else
 		ha->isp_ops->intr_handler(0, rsp);
-	local_irq_restore(flags);
+	local_irq_restore_nort(flags);
 }
 
 static inline uint8_t *
diff -Nur linux-3.18.12.orig/drivers/thermal/x86_pkg_temp_thermal.c linux-3.18.12/drivers/thermal/x86_pkg_temp_thermal.c
--- linux-3.18.12.orig/drivers/thermal/x86_pkg_temp_thermal.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/thermal/x86_pkg_temp_thermal.c	2015-04-26 13:32:22.407684003 -0500
@@ -29,6 +29,7 @@
 #include <linux/pm.h>
 #include <linux/thermal.h>
 #include <linux/debugfs.h>
+#include <linux/work-simple.h>
 #include <asm/cpu_device_id.h>
 #include <asm/mce.h>
 
@@ -352,7 +353,7 @@
 	}
 }
 
-static int pkg_temp_thermal_platform_thermal_notify(__u64 msr_val)
+static void platform_thermal_notify_work(struct swork_event *event)
 {
 	unsigned long flags;
 	int cpu = smp_processor_id();
@@ -369,7 +370,7 @@
 			pkg_work_scheduled[phy_id]) {
 		disable_pkg_thres_interrupt();
 		spin_unlock_irqrestore(&pkg_work_lock, flags);
-		return -EINVAL;
+		return;
 	}
 	pkg_work_scheduled[phy_id] = 1;
 	spin_unlock_irqrestore(&pkg_work_lock, flags);
@@ -378,9 +379,48 @@
 	schedule_delayed_work_on(cpu,
 				&per_cpu(pkg_temp_thermal_threshold_work, cpu),
 				msecs_to_jiffies(notify_delay_ms));
+}
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+static struct swork_event notify_work;
+
+static int thermal_notify_work_init(void)
+{
+	int err;
+
+	err = swork_get();
+	if (err)
+		return err;
+
+	INIT_SWORK(&notify_work, platform_thermal_notify_work);
 	return 0;
 }
 
+static void thermal_notify_work_cleanup(void)
+{
+	swork_put();
+}
+
+static int pkg_temp_thermal_platform_thermal_notify(__u64 msr_val)
+{
+	swork_queue(&notify_work);
+	return 0;
+}
+
+#else  /* !CONFIG_PREEMPT_RT_FULL */
+
+static int thermal_notify_work_init(void) { return 0; }
+
+static int thermal_notify_work_cleanup(void) {  }
+
+static int pkg_temp_thermal_platform_thermal_notify(__u64 msr_val)
+{
+	platform_thermal_notify_work(NULL);
+
+	return 0;
+}
+#endif /* CONFIG_PREEMPT_RT_FULL */
+
 static int find_siblings_cpu(int cpu)
 {
 	int i;
@@ -584,6 +624,9 @@
 	if (!x86_match_cpu(pkg_temp_thermal_ids))
 		return -ENODEV;
 
+	if (!thermal_notify_work_init())
+		return -ENODEV;
+
 	spin_lock_init(&pkg_work_lock);
 	platform_thermal_package_notify =
 			pkg_temp_thermal_platform_thermal_notify;
@@ -608,7 +651,7 @@
 	kfree(pkg_work_scheduled);
 	platform_thermal_package_notify = NULL;
 	platform_thermal_package_rate_control = NULL;
-
+	thermal_notify_work_cleanup();
 	return -ENODEV;
 }
 
@@ -633,6 +676,7 @@
 	mutex_unlock(&phy_dev_list_mutex);
 	platform_thermal_package_notify = NULL;
 	platform_thermal_package_rate_control = NULL;
+	thermal_notify_work_cleanup();
 	for_each_online_cpu(i)
 		cancel_delayed_work_sync(
 			&per_cpu(pkg_temp_thermal_threshold_work, i));
diff -Nur linux-3.18.12.orig/drivers/tty/serial/8250/8250_core.c linux-3.18.12/drivers/tty/serial/8250/8250_core.c
--- linux-3.18.12.orig/drivers/tty/serial/8250/8250_core.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/tty/serial/8250/8250_core.c	2015-04-26 13:32:22.407684003 -0500
@@ -37,6 +37,7 @@
 #include <linux/nmi.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
+#include <linux/kdb.h>
 #include <linux/uaccess.h>
 #include <linux/pm_runtime.h>
 #ifdef CONFIG_SPARC
@@ -81,7 +82,16 @@
 #define DEBUG_INTR(fmt...)	do { } while (0)
 #endif
 
-#define PASS_LIMIT	512
+/*
+ * On -rt we can have a more delays, and legitimately
+ * so - so don't drop work spuriously and spam the
+ * syslog:
+ */
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define PASS_LIMIT	1000000
+#else
+# define PASS_LIMIT	512
+#endif
 
 #define BOTH_EMPTY 	(UART_LSR_TEMT | UART_LSR_THRE)
 
@@ -3197,7 +3207,7 @@
 
 	serial8250_rpm_get(up);
 
-	if (port->sysrq || oops_in_progress)
+	if (port->sysrq || oops_in_progress || in_kdb_printk())
 		locked = spin_trylock_irqsave(&port->lock, flags);
 	else
 		spin_lock_irqsave(&port->lock, flags);
diff -Nur linux-3.18.12.orig/drivers/tty/serial/amba-pl011.c linux-3.18.12/drivers/tty/serial/amba-pl011.c
--- linux-3.18.12.orig/drivers/tty/serial/amba-pl011.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/tty/serial/amba-pl011.c	2015-04-26 13:32:22.407684003 -0500
@@ -1935,13 +1935,19 @@
 
 	clk_enable(uap->clk);
 
-	local_irq_save(flags);
+	/*
+	 * local_irq_save(flags);
+	 *
+	 * This local_irq_save() is nonsense. If we come in via sysrq
+	 * handling then interrupts are already disabled. Aside of
+	 * that the port.sysrq check is racy on SMP regardless.
+	*/
 	if (uap->port.sysrq)
 		locked = 0;
 	else if (oops_in_progress)
-		locked = spin_trylock(&uap->port.lock);
+		locked = spin_trylock_irqsave(&uap->port.lock, flags);
 	else
-		spin_lock(&uap->port.lock);
+		spin_lock_irqsave(&uap->port.lock, flags);
 
 	/*
 	 *	First save the CR then disable the interrupts
@@ -1963,8 +1969,7 @@
 	writew(old_cr, uap->port.membase + UART011_CR);
 
 	if (locked)
-		spin_unlock(&uap->port.lock);
-	local_irq_restore(flags);
+		spin_unlock_irqrestore(&uap->port.lock, flags);
 
 	clk_disable(uap->clk);
 }
diff -Nur linux-3.18.12.orig/drivers/tty/serial/omap-serial.c linux-3.18.12/drivers/tty/serial/omap-serial.c
--- linux-3.18.12.orig/drivers/tty/serial/omap-serial.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/tty/serial/omap-serial.c	2015-04-26 13:32:22.407684003 -0500
@@ -1270,13 +1270,10 @@
 
 	pm_runtime_get_sync(up->dev);
 
-	local_irq_save(flags);
-	if (up->port.sysrq)
-		locked = 0;
-	else if (oops_in_progress)
-		locked = spin_trylock(&up->port.lock);
+	if (up->port.sysrq || oops_in_progress)
+		locked = spin_trylock_irqsave(&up->port.lock, flags);
 	else
-		spin_lock(&up->port.lock);
+		spin_lock_irqsave(&up->port.lock, flags);
 
 	/*
 	 * First save the IER then disable the interrupts
@@ -1305,8 +1302,7 @@
 	pm_runtime_mark_last_busy(up->dev);
 	pm_runtime_put_autosuspend(up->dev);
 	if (locked)
-		spin_unlock(&up->port.lock);
-	local_irq_restore(flags);
+		spin_unlock_irqrestore(&up->port.lock, flags);
 }
 
 static int __init
diff -Nur linux-3.18.12.orig/drivers/usb/core/hcd.c linux-3.18.12/drivers/usb/core/hcd.c
--- linux-3.18.12.orig/drivers/usb/core/hcd.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/usb/core/hcd.c	2015-04-26 13:32:22.407684003 -0500
@@ -1681,9 +1681,9 @@
 	 * and no one may trigger the above deadlock situation when
 	 * running complete() in tasklet.
 	 */
-	local_irq_save(flags);
+	local_irq_save_nort(flags);
 	urb->complete(urb);
-	local_irq_restore(flags);
+	local_irq_restore_nort(flags);
 
 	usb_anchor_resume_wakeups(anchor);
 	atomic_dec(&urb->use_count);
diff -Nur linux-3.18.12.orig/drivers/usb/gadget/function/f_fs.c linux-3.18.12/drivers/usb/gadget/function/f_fs.c
--- linux-3.18.12.orig/drivers/usb/gadget/function/f_fs.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/usb/gadget/function/f_fs.c	2015-04-26 13:32:22.407684003 -0500
@@ -1428,7 +1428,7 @@
 		pr_info("%s(): freeing\n", __func__);
 		ffs_data_clear(ffs);
 		BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
-		       waitqueue_active(&ffs->ep0req_completion.wait));
+		       swaitqueue_active(&ffs->ep0req_completion.wait));
 		kfree(ffs->dev_name);
 		kfree(ffs);
 	}
diff -Nur linux-3.18.12.orig/drivers/usb/gadget/legacy/inode.c linux-3.18.12/drivers/usb/gadget/legacy/inode.c
--- linux-3.18.12.orig/drivers/usb/gadget/legacy/inode.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/drivers/usb/gadget/legacy/inode.c	2015-04-26 13:32:22.407684003 -0500
@@ -339,7 +339,7 @@
 	spin_unlock_irq (&epdata->dev->lock);
 
 	if (likely (value == 0)) {
-		value = wait_event_interruptible (done.wait, done.done);
+		value = swait_event_interruptible (done.wait, done.done);
 		if (value != 0) {
 			spin_lock_irq (&epdata->dev->lock);
 			if (likely (epdata->ep != NULL)) {
@@ -348,7 +348,7 @@
 				usb_ep_dequeue (epdata->ep, epdata->req);
 				spin_unlock_irq (&epdata->dev->lock);
 
-				wait_event (done.wait, done.done);
+				swait_event (done.wait, done.done);
 				if (epdata->status == -ECONNRESET)
 					epdata->status = -EINTR;
 			} else {
diff -Nur linux-3.18.12.orig/fs/aio.c linux-3.18.12/fs/aio.c
--- linux-3.18.12.orig/fs/aio.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/fs/aio.c	2015-04-26 13:32:22.407684003 -0500
@@ -40,6 +40,7 @@
 #include <linux/ramfs.h>
 #include <linux/percpu-refcount.h>
 #include <linux/mount.h>
+#include <linux/work-simple.h>
 
 #include <asm/kmap_types.h>
 #include <asm/uaccess.h>
@@ -110,7 +111,7 @@
 	struct page		**ring_pages;
 	long			nr_pages;
 
-	struct work_struct	free_work;
+	struct swork_event	free_work;
 
 	/*
 	 * signals when all in-flight requests are done
@@ -226,6 +227,7 @@
 		.mount		= aio_mount,
 		.kill_sb	= kill_anon_super,
 	};
+	BUG_ON(swork_get());
 	aio_mnt = kern_mount(&aio_fs);
 	if (IS_ERR(aio_mnt))
 		panic("Failed to create aio fs mount.");
@@ -505,9 +507,9 @@
 	return cancel(kiocb);
 }
 
-static void free_ioctx(struct work_struct *work)
+static void free_ioctx(struct swork_event *sev)
 {
-	struct kioctx *ctx = container_of(work, struct kioctx, free_work);
+	struct kioctx *ctx = container_of(sev, struct kioctx, free_work);
 
 	pr_debug("freeing %p\n", ctx);
 
@@ -526,8 +528,8 @@
 	if (ctx->requests_done)
 		complete(ctx->requests_done);
 
-	INIT_WORK(&ctx->free_work, free_ioctx);
-	schedule_work(&ctx->free_work);
+	INIT_SWORK(&ctx->free_work, free_ioctx);
+	swork_queue(&ctx->free_work);
 }
 
 /*
@@ -535,9 +537,9 @@
  * and ctx->users has dropped to 0, so we know no more kiocbs can be submitted -
  * now it's safe to cancel any that need to be.
  */
-static void free_ioctx_users(struct percpu_ref *ref)
+static void free_ioctx_users_work(struct swork_event *sev)
 {
-	struct kioctx *ctx = container_of(ref, struct kioctx, users);
+	struct kioctx *ctx = container_of(sev, struct kioctx, free_work);
 	struct kiocb *req;
 
 	spin_lock_irq(&ctx->ctx_lock);
@@ -556,6 +558,14 @@
 	percpu_ref_put(&ctx->reqs);
 }
 
+static void free_ioctx_users(struct percpu_ref *ref)
+{
+	struct kioctx *ctx = container_of(ref, struct kioctx, users);
+
+	INIT_SWORK(&ctx->free_work, free_ioctx_users_work);
+	swork_queue(&ctx->free_work);
+}
+
 static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm)
 {
 	unsigned i, new_nr;
diff -Nur linux-3.18.12.orig/fs/autofs4/autofs_i.h linux-3.18.12/fs/autofs4/autofs_i.h
--- linux-3.18.12.orig/fs/autofs4/autofs_i.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/fs/autofs4/autofs_i.h	2015-04-26 13:32:22.411684003 -0500
@@ -34,6 +34,7 @@
 #include <linux/sched.h>
 #include <linux/mount.h>
 #include <linux/namei.h>
+#include <linux/delay.h>
 #include <asm/current.h>
 #include <asm/uaccess.h>
 
diff -Nur linux-3.18.12.orig/fs/autofs4/expire.c linux-3.18.12/fs/autofs4/expire.c
--- linux-3.18.12.orig/fs/autofs4/expire.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/fs/autofs4/expire.c	2015-04-26 13:32:22.411684003 -0500
@@ -151,7 +151,7 @@
 			parent = p->d_parent;
 			if (!spin_trylock(&parent->d_lock)) {
 				spin_unlock(&p->d_lock);
-				cpu_relax();
+				cpu_chill();
 				goto relock;
 			}
 			spin_unlock(&p->d_lock);
diff -Nur linux-3.18.12.orig/fs/buffer.c linux-3.18.12/fs/buffer.c
--- linux-3.18.12.orig/fs/buffer.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/fs/buffer.c	2015-04-26 13:32:22.411684003 -0500
@@ -301,8 +301,7 @@
 	 * decide that the page is now completely done.
 	 */
 	first = page_buffers(page);
-	local_irq_save(flags);
-	bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
+	flags = bh_uptodate_lock_irqsave(first);
 	clear_buffer_async_read(bh);
 	unlock_buffer(bh);
 	tmp = bh;
@@ -315,8 +314,7 @@
 		}
 		tmp = tmp->b_this_page;
 	} while (tmp != bh);
-	bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
-	local_irq_restore(flags);
+	bh_uptodate_unlock_irqrestore(first, flags);
 
 	/*
 	 * If none of the buffers had errors and they are all
@@ -328,9 +326,7 @@
 	return;
 
 still_busy:
-	bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
-	local_irq_restore(flags);
-	return;
+	bh_uptodate_unlock_irqrestore(first, flags);
 }
 
 /*
@@ -358,8 +354,7 @@
 	}
 
 	first = page_buffers(page);
-	local_irq_save(flags);
-	bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
+	flags = bh_uptodate_lock_irqsave(first);
 
 	clear_buffer_async_write(bh);
 	unlock_buffer(bh);
@@ -371,15 +366,12 @@
 		}
 		tmp = tmp->b_this_page;
 	}
-	bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
-	local_irq_restore(flags);
+	bh_uptodate_unlock_irqrestore(first, flags);
 	end_page_writeback(page);
 	return;
 
 still_busy:
-	bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
-	local_irq_restore(flags);
-	return;
+	bh_uptodate_unlock_irqrestore(first, flags);
 }
 EXPORT_SYMBOL(end_buffer_async_write);
 
@@ -3325,6 +3317,7 @@
 	struct buffer_head *ret = kmem_cache_zalloc(bh_cachep, gfp_flags);
 	if (ret) {
 		INIT_LIST_HEAD(&ret->b_assoc_buffers);
+		buffer_head_init_locks(ret);
 		preempt_disable();
 		__this_cpu_inc(bh_accounting.nr);
 		recalc_bh_state();
diff -Nur linux-3.18.12.orig/fs/dcache.c linux-3.18.12/fs/dcache.c
--- linux-3.18.12.orig/fs/dcache.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/fs/dcache.c	2015-04-26 13:32:22.411684003 -0500
@@ -19,6 +19,7 @@
 #include <linux/mm.h>
 #include <linux/fs.h>
 #include <linux/fsnotify.h>
+#include <linux/delay.h>
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/hash.h>
@@ -552,7 +553,7 @@
 
 failed:
 	spin_unlock(&dentry->d_lock);
-	cpu_relax();
+	cpu_chill();
 	return dentry; /* try again with same dentry */
 }
 
@@ -2285,7 +2286,7 @@
 	if (dentry->d_lockref.count == 1) {
 		if (!spin_trylock(&inode->i_lock)) {
 			spin_unlock(&dentry->d_lock);
-			cpu_relax();
+			cpu_chill();
 			goto again;
 		}
 		dentry->d_flags &= ~DCACHE_CANT_MOUNT;
diff -Nur linux-3.18.12.orig/fs/eventpoll.c linux-3.18.12/fs/eventpoll.c
--- linux-3.18.12.orig/fs/eventpoll.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/fs/eventpoll.c	2015-04-26 13:32:22.411684003 -0500
@@ -505,12 +505,12 @@
  */
 static void ep_poll_safewake(wait_queue_head_t *wq)
 {
-	int this_cpu = get_cpu();
+	int this_cpu = get_cpu_light();
 
 	ep_call_nested(&poll_safewake_ncalls, EP_MAX_NESTS,
 		       ep_poll_wakeup_proc, NULL, wq, (void *) (long) this_cpu);
 
-	put_cpu();
+	put_cpu_light();
 }
 
 static void ep_remove_wait_queue(struct eppoll_entry *pwq)
diff -Nur linux-3.18.12.orig/fs/exec.c linux-3.18.12/fs/exec.c
--- linux-3.18.12.orig/fs/exec.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/fs/exec.c	2015-04-26 13:32:22.411684003 -0500
@@ -841,12 +841,14 @@
 		}
 	}
 	task_lock(tsk);
+	preempt_disable_rt();
 	active_mm = tsk->active_mm;
 	tsk->mm = mm;
 	tsk->active_mm = mm;
 	activate_mm(active_mm, mm);
 	tsk->mm->vmacache_seqnum = 0;
 	vmacache_flush(tsk);
+	preempt_enable_rt();
 	task_unlock(tsk);
 	if (old_mm) {
 		up_read(&old_mm->mmap_sem);
diff -Nur linux-3.18.12.orig/fs/jbd/checkpoint.c linux-3.18.12/fs/jbd/checkpoint.c
--- linux-3.18.12.orig/fs/jbd/checkpoint.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/fs/jbd/checkpoint.c	2015-04-26 13:32:22.411684003 -0500
@@ -129,6 +129,8 @@
 		if (journal->j_flags & JFS_ABORT)
 			return;
 		spin_unlock(&journal->j_state_lock);
+		if (current->plug)
+			io_schedule();
 		mutex_lock(&journal->j_checkpoint_mutex);
 
 		/*
diff -Nur linux-3.18.12.orig/fs/jbd2/checkpoint.c linux-3.18.12/fs/jbd2/checkpoint.c
--- linux-3.18.12.orig/fs/jbd2/checkpoint.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/fs/jbd2/checkpoint.c	2015-04-26 13:32:22.411684003 -0500
@@ -116,6 +116,8 @@
 	nblocks = jbd2_space_needed(journal);
 	while (jbd2_log_space_left(journal) < nblocks) {
 		write_unlock(&journal->j_state_lock);
+		if (current->plug)
+			io_schedule();
 		mutex_lock(&journal->j_checkpoint_mutex);
 
 		/*
diff -Nur linux-3.18.12.orig/fs/namespace.c linux-3.18.12/fs/namespace.c
--- linux-3.18.12.orig/fs/namespace.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/fs/namespace.c	2015-04-26 13:32:22.411684003 -0500
@@ -14,6 +14,7 @@
 #include <linux/mnt_namespace.h>
 #include <linux/user_namespace.h>
 #include <linux/namei.h>
+#include <linux/delay.h>
 #include <linux/security.h>
 #include <linux/idr.h>
 #include <linux/init.h>		/* init_rootfs */
@@ -344,8 +345,11 @@
 	 * incremented count after it has set MNT_WRITE_HOLD.
 	 */
 	smp_mb();
-	while (ACCESS_ONCE(mnt->mnt.mnt_flags) & MNT_WRITE_HOLD)
-		cpu_relax();
+	while (ACCESS_ONCE(mnt->mnt.mnt_flags) & MNT_WRITE_HOLD) {
+		preempt_enable();
+		cpu_chill();
+		preempt_disable();
+	}
 	/*
 	 * After the slowpath clears MNT_WRITE_HOLD, mnt_is_readonly will
 	 * be set to match its requirements. So we must not load that until
diff -Nur linux-3.18.12.orig/fs/ntfs/aops.c linux-3.18.12/fs/ntfs/aops.c
--- linux-3.18.12.orig/fs/ntfs/aops.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/fs/ntfs/aops.c	2015-04-26 13:32:22.411684003 -0500
@@ -107,8 +107,7 @@
 				"0x%llx.", (unsigned long long)bh->b_blocknr);
 	}
 	first = page_buffers(page);
-	local_irq_save(flags);
-	bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
+	flags = bh_uptodate_lock_irqsave(first);
 	clear_buffer_async_read(bh);
 	unlock_buffer(bh);
 	tmp = bh;
@@ -123,8 +122,7 @@
 		}
 		tmp = tmp->b_this_page;
 	} while (tmp != bh);
-	bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
-	local_irq_restore(flags);
+	bh_uptodate_unlock_irqrestore(first, flags);
 	/*
 	 * If none of the buffers had errors then we can set the page uptodate,
 	 * but we first have to perform the post read mst fixups, if the
@@ -145,13 +143,13 @@
 		recs = PAGE_CACHE_SIZE / rec_size;
 		/* Should have been verified before we got here... */
 		BUG_ON(!recs);
-		local_irq_save(flags);
+		local_irq_save_nort(flags);
 		kaddr = kmap_atomic(page);
 		for (i = 0; i < recs; i++)
 			post_read_mst_fixup((NTFS_RECORD*)(kaddr +
 					i * rec_size), rec_size);
 		kunmap_atomic(kaddr);
-		local_irq_restore(flags);
+		local_irq_restore_nort(flags);
 		flush_dcache_page(page);
 		if (likely(page_uptodate && !PageError(page)))
 			SetPageUptodate(page);
@@ -159,9 +157,7 @@
 	unlock_page(page);
 	return;
 still_busy:
-	bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
-	local_irq_restore(flags);
-	return;
+	bh_uptodate_unlock_irqrestore(first, flags);
 }
 
 /**
diff -Nur linux-3.18.12.orig/fs/timerfd.c linux-3.18.12/fs/timerfd.c
--- linux-3.18.12.orig/fs/timerfd.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/fs/timerfd.c	2015-04-26 13:32:22.411684003 -0500
@@ -449,7 +449,10 @@
 				break;
 		}
 		spin_unlock_irq(&ctx->wqh.lock);
-		cpu_relax();
+		if (isalarm(ctx))
+			hrtimer_wait_for_timer(&ctx->t.alarm.timer);
+		else
+			hrtimer_wait_for_timer(&ctx->t.tmr);
 	}
 
 	/*
diff -Nur linux-3.18.12.orig/include/acpi/platform/aclinux.h linux-3.18.12/include/acpi/platform/aclinux.h
--- linux-3.18.12.orig/include/acpi/platform/aclinux.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/acpi/platform/aclinux.h	2015-04-26 13:32:22.415684003 -0500
@@ -123,6 +123,7 @@
 
 #define acpi_cache_t                        struct kmem_cache
 #define acpi_spinlock                       spinlock_t *
+#define acpi_raw_spinlock		raw_spinlock_t *
 #define acpi_cpu_flags                      unsigned long
 
 /* Use native linux version of acpi_os_allocate_zeroed */
@@ -141,6 +142,20 @@
 #define ACPI_USE_ALTERNATE_PROTOTYPE_acpi_os_get_thread_id
 #define ACPI_USE_ALTERNATE_PROTOTYPE_acpi_os_create_lock
 
+#define acpi_os_create_raw_lock(__handle)			\
+({								\
+	 raw_spinlock_t *lock = ACPI_ALLOCATE(sizeof(*lock));	\
+								\
+	 if (lock) {						\
+		*(__handle) = lock;				\
+		raw_spin_lock_init(*(__handle));		\
+	 }							\
+	 lock ? AE_OK : AE_NO_MEMORY;				\
+ })
+
+#define acpi_os_delete_raw_lock(__handle)	kfree(__handle)
+
+
 /*
  * OSL interfaces used by debugger/disassembler
  */
diff -Nur linux-3.18.12.orig/include/asm-generic/bug.h linux-3.18.12/include/asm-generic/bug.h
--- linux-3.18.12.orig/include/asm-generic/bug.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/asm-generic/bug.h	2015-04-26 13:32:22.415684003 -0500
@@ -206,6 +206,20 @@
 # define WARN_ON_SMP(x)			({0;})
 #endif
 
+#ifdef CONFIG_PREEMPT_RT_BASE
+# define BUG_ON_RT(c)			BUG_ON(c)
+# define BUG_ON_NONRT(c)		do { } while (0)
+# define WARN_ON_RT(condition)		WARN_ON(condition)
+# define WARN_ON_NONRT(condition)	do { } while (0)
+# define WARN_ON_ONCE_NONRT(condition)	do { } while (0)
+#else
+# define BUG_ON_RT(c)			do { } while (0)
+# define BUG_ON_NONRT(c)		BUG_ON(c)
+# define WARN_ON_RT(condition)		do { } while (0)
+# define WARN_ON_NONRT(condition)	WARN_ON(condition)
+# define WARN_ON_ONCE_NONRT(condition)	WARN_ON_ONCE(condition)
+#endif
+
 #endif /* __ASSEMBLY__ */
 
 #endif
diff -Nur linux-3.18.12.orig/include/linux/blkdev.h linux-3.18.12/include/linux/blkdev.h
--- linux-3.18.12.orig/include/linux/blkdev.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/blkdev.h	2015-04-26 13:32:22.415684003 -0500
@@ -101,6 +101,7 @@
 	struct list_head queuelist;
 	union {
 		struct call_single_data csd;
+		struct work_struct work;
 		unsigned long fifo_time;
 	};
 
@@ -478,7 +479,7 @@
 	struct throtl_data *td;
 #endif
 	struct rcu_head		rcu_head;
-	wait_queue_head_t	mq_freeze_wq;
+	struct swait_head	mq_freeze_wq;
 	struct percpu_ref	mq_usage_counter;
 	struct list_head	all_q_node;
 
diff -Nur linux-3.18.12.orig/include/linux/blk-mq.h linux-3.18.12/include/linux/blk-mq.h
--- linux-3.18.12.orig/include/linux/blk-mq.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/blk-mq.h	2015-04-26 13:32:22.415684003 -0500
@@ -169,6 +169,7 @@
 
 struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *, const int ctx_index);
 struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_tag_set *, unsigned int, int);
+void __blk_mq_complete_request_remote_work(struct work_struct *work);
 
 void blk_mq_start_request(struct request *rq);
 void blk_mq_end_request(struct request *rq, int error);
diff -Nur linux-3.18.12.orig/include/linux/bottom_half.h linux-3.18.12/include/linux/bottom_half.h
--- linux-3.18.12.orig/include/linux/bottom_half.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/bottom_half.h	2015-04-26 13:32:22.415684003 -0500
@@ -4,6 +4,17 @@
 #include <linux/preempt.h>
 #include <linux/preempt_mask.h>
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+
+extern void local_bh_disable(void);
+extern void _local_bh_enable(void);
+extern void local_bh_enable(void);
+extern void local_bh_enable_ip(unsigned long ip);
+extern void __local_bh_disable_ip(unsigned long ip, unsigned int cnt);
+extern void __local_bh_enable_ip(unsigned long ip, unsigned int cnt);
+
+#else
+
 #ifdef CONFIG_TRACE_IRQFLAGS
 extern void __local_bh_disable_ip(unsigned long ip, unsigned int cnt);
 #else
@@ -31,5 +42,6 @@
 {
 	__local_bh_enable_ip(_THIS_IP_, SOFTIRQ_DISABLE_OFFSET);
 }
+#endif
 
 #endif /* _LINUX_BH_H */
diff -Nur linux-3.18.12.orig/include/linux/buffer_head.h linux-3.18.12/include/linux/buffer_head.h
--- linux-3.18.12.orig/include/linux/buffer_head.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/buffer_head.h	2015-04-26 13:32:22.415684003 -0500
@@ -75,8 +75,52 @@
 	struct address_space *b_assoc_map;	/* mapping this buffer is
 						   associated with */
 	atomic_t b_count;		/* users using this buffer_head */
+#ifdef CONFIG_PREEMPT_RT_BASE
+	spinlock_t b_uptodate_lock;
+#if defined(CONFIG_JBD) || defined(CONFIG_JBD_MODULE) || \
+	defined(CONFIG_JBD2) || defined(CONFIG_JBD2_MODULE)
+	spinlock_t b_state_lock;
+	spinlock_t b_journal_head_lock;
+#endif
+#endif
 };
 
+static inline unsigned long bh_uptodate_lock_irqsave(struct buffer_head *bh)
+{
+	unsigned long flags;
+
+#ifndef CONFIG_PREEMPT_RT_BASE
+	local_irq_save(flags);
+	bit_spin_lock(BH_Uptodate_Lock, &bh->b_state);
+#else
+	spin_lock_irqsave(&bh->b_uptodate_lock, flags);
+#endif
+	return flags;
+}
+
+static inline void
+bh_uptodate_unlock_irqrestore(struct buffer_head *bh, unsigned long flags)
+{
+#ifndef CONFIG_PREEMPT_RT_BASE
+	bit_spin_unlock(BH_Uptodate_Lock, &bh->b_state);
+	local_irq_restore(flags);
+#else
+	spin_unlock_irqrestore(&bh->b_uptodate_lock, flags);
+#endif
+}
+
+static inline void buffer_head_init_locks(struct buffer_head *bh)
+{
+#ifdef CONFIG_PREEMPT_RT_BASE
+	spin_lock_init(&bh->b_uptodate_lock);
+#if defined(CONFIG_JBD) || defined(CONFIG_JBD_MODULE) || \
+	defined(CONFIG_JBD2) || defined(CONFIG_JBD2_MODULE)
+	spin_lock_init(&bh->b_state_lock);
+	spin_lock_init(&bh->b_journal_head_lock);
+#endif
+#endif
+}
+
 /*
  * macro tricks to expand the set_buffer_foo(), clear_buffer_foo()
  * and buffer_foo() functions.
diff -Nur linux-3.18.12.orig/include/linux/cgroup.h linux-3.18.12/include/linux/cgroup.h
--- linux-3.18.12.orig/include/linux/cgroup.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/cgroup.h	2015-04-26 13:32:22.415684003 -0500
@@ -22,6 +22,7 @@
 #include <linux/seq_file.h>
 #include <linux/kernfs.h>
 #include <linux/wait.h>
+#include <linux/work-simple.h>
 
 #ifdef CONFIG_CGROUPS
 
@@ -91,6 +92,7 @@
 	/* percpu_ref killing and RCU release */
 	struct rcu_head rcu_head;
 	struct work_struct destroy_work;
+	struct swork_event destroy_swork;
 };
 
 /* bits in struct cgroup_subsys_state flags field */
diff -Nur linux-3.18.12.orig/include/linux/completion.h linux-3.18.12/include/linux/completion.h
--- linux-3.18.12.orig/include/linux/completion.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/completion.h	2015-04-26 13:32:22.415684003 -0500
@@ -7,8 +7,7 @@
  * Atomic wait-for-completion handler data structures.
  * See kernel/sched/completion.c for details.
  */
-
-#include <linux/wait.h>
+#include <linux/wait-simple.h>
 
 /*
  * struct completion - structure used to maintain state for a "completion"
@@ -24,11 +23,11 @@
  */
 struct completion {
 	unsigned int done;
-	wait_queue_head_t wait;
+	struct swait_head wait;
 };
 
 #define COMPLETION_INITIALIZER(work) \
-	{ 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait) }
+	{ 0, SWAIT_HEAD_INITIALIZER((work).wait) }
 
 #define COMPLETION_INITIALIZER_ONSTACK(work) \
 	({ init_completion(&work); work; })
@@ -73,7 +72,7 @@
 static inline void init_completion(struct completion *x)
 {
 	x->done = 0;
-	init_waitqueue_head(&x->wait);
+	init_swait_head(&x->wait);
 }
 
 /**
diff -Nur linux-3.18.12.orig/include/linux/cpu.h linux-3.18.12/include/linux/cpu.h
--- linux-3.18.12.orig/include/linux/cpu.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/cpu.h	2015-04-26 13:32:22.415684003 -0500
@@ -217,6 +217,8 @@
 extern void put_online_cpus(void);
 extern void cpu_hotplug_disable(void);
 extern void cpu_hotplug_enable(void);
+extern void pin_current_cpu(void);
+extern void unpin_current_cpu(void);
 #define hotcpu_notifier(fn, pri)	cpu_notifier(fn, pri)
 #define __hotcpu_notifier(fn, pri)	__cpu_notifier(fn, pri)
 #define register_hotcpu_notifier(nb)	register_cpu_notifier(nb)
@@ -235,6 +237,8 @@
 #define put_online_cpus()	do { } while (0)
 #define cpu_hotplug_disable()	do { } while (0)
 #define cpu_hotplug_enable()	do { } while (0)
+static inline void pin_current_cpu(void) { }
+static inline void unpin_current_cpu(void) { }
 #define hotcpu_notifier(fn, pri)	do { (void)(fn); } while (0)
 #define __hotcpu_notifier(fn, pri)	do { (void)(fn); } while (0)
 /* These aren't inline functions due to a GCC bug. */
diff -Nur linux-3.18.12.orig/include/linux/delay.h linux-3.18.12/include/linux/delay.h
--- linux-3.18.12.orig/include/linux/delay.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/delay.h	2015-04-26 13:32:22.415684003 -0500
@@ -52,4 +52,10 @@
 	msleep(seconds * 1000);
 }
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+extern void cpu_chill(void);
+#else
+# define cpu_chill()	cpu_relax()
+#endif
+
 #endif /* defined(_LINUX_DELAY_H) */
diff -Nur linux-3.18.12.orig/include/linux/ftrace_event.h linux-3.18.12/include/linux/ftrace_event.h
--- linux-3.18.12.orig/include/linux/ftrace_event.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/ftrace_event.h	2015-04-26 13:32:22.415684003 -0500
@@ -61,6 +61,9 @@
 	unsigned char		flags;
 	unsigned char		preempt_count;
 	int			pid;
+	unsigned short		migrate_disable;
+	unsigned short		padding;
+	unsigned char		preempt_lazy_count;
 };
 
 #define FTRACE_MAX_EVENT						\
diff -Nur linux-3.18.12.orig/include/linux/highmem.h linux-3.18.12/include/linux/highmem.h
--- linux-3.18.12.orig/include/linux/highmem.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/highmem.h	2015-04-26 13:32:22.415684003 -0500
@@ -7,6 +7,7 @@
 #include <linux/mm.h>
 #include <linux/uaccess.h>
 #include <linux/hardirq.h>
+#include <linux/sched.h>
 
 #include <asm/cacheflush.h>
 
@@ -85,32 +86,51 @@
 
 #if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 DECLARE_PER_CPU(int, __kmap_atomic_idx);
+#endif
 
 static inline int kmap_atomic_idx_push(void)
 {
+#ifndef CONFIG_PREEMPT_RT_FULL
 	int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1;
 
-#ifdef CONFIG_DEBUG_HIGHMEM
+# ifdef CONFIG_DEBUG_HIGHMEM
 	WARN_ON_ONCE(in_irq() && !irqs_disabled());
 	BUG_ON(idx >= KM_TYPE_NR);
-#endif
+# endif
 	return idx;
+#else
+	current->kmap_idx++;
+	BUG_ON(current->kmap_idx > KM_TYPE_NR);
+	return current->kmap_idx - 1;
+#endif
 }
 
 static inline int kmap_atomic_idx(void)
 {
+#ifndef CONFIG_PREEMPT_RT_FULL
 	return __this_cpu_read(__kmap_atomic_idx) - 1;
+#else
+	return current->kmap_idx - 1;
+#endif
 }
 
 static inline void kmap_atomic_idx_pop(void)
 {
-#ifdef CONFIG_DEBUG_HIGHMEM
+#ifndef CONFIG_PREEMPT_RT_FULL
+# ifdef CONFIG_DEBUG_HIGHMEM
 	int idx = __this_cpu_dec_return(__kmap_atomic_idx);
 
 	BUG_ON(idx < 0);
-#else
+# else
 	__this_cpu_dec(__kmap_atomic_idx);
+# endif
+#else
+	current->kmap_idx--;
+# ifdef CONFIG_DEBUG_HIGHMEM
+	BUG_ON(current->kmap_idx < 0);
+# endif
 #endif
 }
 
diff -Nur linux-3.18.12.orig/include/linux/hrtimer.h linux-3.18.12/include/linux/hrtimer.h
--- linux-3.18.12.orig/include/linux/hrtimer.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/hrtimer.h	2015-04-26 13:32:22.415684003 -0500
@@ -111,6 +111,11 @@
 	enum hrtimer_restart		(*function)(struct hrtimer *);
 	struct hrtimer_clock_base	*base;
 	unsigned long			state;
+	struct list_head		cb_entry;
+	int				irqsafe;
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+	ktime_t				praecox;
+#endif
 #ifdef CONFIG_TIMER_STATS
 	int				start_pid;
 	void				*start_site;
@@ -147,6 +152,7 @@
 	int			index;
 	clockid_t		clockid;
 	struct timerqueue_head	active;
+	struct list_head	expired;
 	ktime_t			resolution;
 	ktime_t			(*get_time)(void);
 	ktime_t			softirq_time;
@@ -192,6 +198,9 @@
 	unsigned long			nr_hangs;
 	ktime_t				max_hang_time;
 #endif
+#ifdef CONFIG_PREEMPT_RT_BASE
+	wait_queue_head_t		wait;
+#endif
 	struct hrtimer_clock_base	clock_base[HRTIMER_MAX_CLOCK_BASES];
 };
 
@@ -379,6 +388,13 @@
 	return hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
 }
 
+/* Softirq preemption could deadlock timer removal */
+#ifdef CONFIG_PREEMPT_RT_BASE
+  extern void hrtimer_wait_for_timer(const struct hrtimer *timer);
+#else
+# define hrtimer_wait_for_timer(timer)	do { cpu_relax(); } while (0)
+#endif
+
 /* Query timers: */
 extern ktime_t hrtimer_get_remaining(const struct hrtimer *timer);
 extern int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp);
diff -Nur linux-3.18.12.orig/include/linux/idr.h linux-3.18.12/include/linux/idr.h
--- linux-3.18.12.orig/include/linux/idr.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/idr.h	2015-04-26 13:32:22.415684003 -0500
@@ -95,10 +95,14 @@
  * Each idr_preload() should be matched with an invocation of this
  * function.  See idr_preload() for details.
  */
+#ifdef CONFIG_PREEMPT_RT_FULL
+void idr_preload_end(void);
+#else
 static inline void idr_preload_end(void)
 {
 	preempt_enable();
 }
+#endif
 
 /**
  * idr_find - return pointer for given id
diff -Nur linux-3.18.12.orig/include/linux/init_task.h linux-3.18.12/include/linux/init_task.h
--- linux-3.18.12.orig/include/linux/init_task.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/init_task.h	2015-04-26 13:32:22.415684003 -0500
@@ -147,9 +147,16 @@
 # define INIT_PERF_EVENTS(tsk)
 #endif
 
+#ifdef CONFIG_PREEMPT_RT_BASE
+# define INIT_TIMER_LIST		.posix_timer_list = NULL,
+#else
+# define INIT_TIMER_LIST
+#endif
+
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
 # define INIT_VTIME(tsk)						\
-	.vtime_seqlock = __SEQLOCK_UNLOCKED(tsk.vtime_seqlock),	\
+	.vtime_lock = __RAW_SPIN_LOCK_UNLOCKED(tsk.vtime_lock),	\
+	.vtime_seq = SEQCNT_ZERO(tsk.vtime_seq),			\
 	.vtime_snap = 0,				\
 	.vtime_snap_whence = VTIME_SYS,
 #else
@@ -219,6 +226,7 @@
 	.cpu_timers	= INIT_CPU_TIMERS(tsk.cpu_timers),		\
 	.pi_lock	= __RAW_SPIN_LOCK_UNLOCKED(tsk.pi_lock),	\
 	.timer_slack_ns = 50000, /* 50 usec default slack */		\
+	INIT_TIMER_LIST							\
 	.pids = {							\
 		[PIDTYPE_PID]  = INIT_PID_LINK(PIDTYPE_PID),		\
 		[PIDTYPE_PGID] = INIT_PID_LINK(PIDTYPE_PGID),		\
diff -Nur linux-3.18.12.orig/include/linux/interrupt.h linux-3.18.12/include/linux/interrupt.h
--- linux-3.18.12.orig/include/linux/interrupt.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/interrupt.h	2015-04-26 13:32:22.415684003 -0500
@@ -57,6 +57,7 @@
  * IRQF_NO_THREAD - Interrupt cannot be threaded
  * IRQF_EARLY_RESUME - Resume IRQ early during syscore instead of at device
  *                resume time.
+ * IRQF_NO_SOFTIRQ_CALL - Do not process softirqs in the irq thread context (RT)
  */
 #define IRQF_DISABLED		0x00000020
 #define IRQF_SHARED		0x00000080
@@ -70,6 +71,7 @@
 #define IRQF_FORCE_RESUME	0x00008000
 #define IRQF_NO_THREAD		0x00010000
 #define IRQF_EARLY_RESUME	0x00020000
+#define IRQF_NO_SOFTIRQ_CALL	0x00080000
 
 #define IRQF_TIMER		(__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD)
 
@@ -180,7 +182,7 @@
 #ifdef CONFIG_LOCKDEP
 # define local_irq_enable_in_hardirq()	do { } while (0)
 #else
-# define local_irq_enable_in_hardirq()	local_irq_enable()
+# define local_irq_enable_in_hardirq()	local_irq_enable_nort()
 #endif
 
 extern void disable_irq_nosync(unsigned int irq);
@@ -210,6 +212,7 @@
 	unsigned int irq;
 	struct kref kref;
 	struct work_struct work;
+	struct list_head list;
 	void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask);
 	void (*release)(struct kref *ref);
 };
@@ -358,9 +361,13 @@
 
 
 #ifdef CONFIG_IRQ_FORCED_THREADING
+# ifndef CONFIG_PREEMPT_RT_BASE
 extern bool force_irqthreads;
+# else
+#  define force_irqthreads	(true)
+# endif
 #else
-#define force_irqthreads	(0)
+#define force_irqthreads	(false)
 #endif
 
 #ifndef __ARCH_SET_SOFTIRQ_PENDING
@@ -416,9 +423,10 @@
 	void	(*action)(struct softirq_action *);
 };
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 asmlinkage void do_softirq(void);
 asmlinkage void __do_softirq(void);
-
+static inline void thread_do_softirq(void) { do_softirq(); }
 #ifdef __ARCH_HAS_DO_SOFTIRQ
 void do_softirq_own_stack(void);
 #else
@@ -427,6 +435,9 @@
 	__do_softirq();
 }
 #endif
+#else
+extern void thread_do_softirq(void);
+#endif
 
 extern void open_softirq(int nr, void (*action)(struct softirq_action *));
 extern void softirq_init(void);
@@ -434,6 +445,7 @@
 
 extern void raise_softirq_irqoff(unsigned int nr);
 extern void raise_softirq(unsigned int nr);
+extern void softirq_check_pending_idle(void);
 
 DECLARE_PER_CPU(struct task_struct *, ksoftirqd);
 
@@ -455,8 +467,9 @@
      to be executed on some cpu at least once after this.
    * If the tasklet is already scheduled, but its execution is still not
      started, it will be executed only once.
-   * If this tasklet is already running on another CPU (or schedule is called
-     from tasklet itself), it is rescheduled for later.
+   * If this tasklet is already running on another CPU, it is rescheduled
+     for later.
+   * Schedule must not be called from the tasklet itself (a lockup occurs)
    * Tasklet is strictly serialized wrt itself, but not
      wrt another tasklets. If client needs some intertask synchronization,
      he makes it with spinlocks.
@@ -481,27 +494,36 @@
 enum
 {
 	TASKLET_STATE_SCHED,	/* Tasklet is scheduled for execution */
-	TASKLET_STATE_RUN	/* Tasklet is running (SMP only) */
+	TASKLET_STATE_RUN,	/* Tasklet is running (SMP only) */
+	TASKLET_STATE_PENDING	/* Tasklet is pending */
 };
 
-#ifdef CONFIG_SMP
+#define TASKLET_STATEF_SCHED	(1 << TASKLET_STATE_SCHED)
+#define TASKLET_STATEF_RUN	(1 << TASKLET_STATE_RUN)
+#define TASKLET_STATEF_PENDING	(1 << TASKLET_STATE_PENDING)
+
+#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT_FULL)
 static inline int tasklet_trylock(struct tasklet_struct *t)
 {
 	return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
 }
 
+static inline int tasklet_tryunlock(struct tasklet_struct *t)
+{
+	return cmpxchg(&t->state, TASKLET_STATEF_RUN, 0) == TASKLET_STATEF_RUN;
+}
+
 static inline void tasklet_unlock(struct tasklet_struct *t)
 {
 	smp_mb__before_atomic();
 	clear_bit(TASKLET_STATE_RUN, &(t)->state);
 }
 
-static inline void tasklet_unlock_wait(struct tasklet_struct *t)
-{
-	while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
-}
+extern void tasklet_unlock_wait(struct tasklet_struct *t);
+
 #else
 #define tasklet_trylock(t) 1
+#define tasklet_tryunlock(t)	1
 #define tasklet_unlock_wait(t) do { } while (0)
 #define tasklet_unlock(t) do { } while (0)
 #endif
@@ -550,17 +572,8 @@
 	smp_mb();
 }
 
-static inline void tasklet_enable(struct tasklet_struct *t)
-{
-	smp_mb__before_atomic();
-	atomic_dec(&t->count);
-}
-
-static inline void tasklet_hi_enable(struct tasklet_struct *t)
-{
-	smp_mb__before_atomic();
-	atomic_dec(&t->count);
-}
+extern void tasklet_enable(struct tasklet_struct *t);
+extern void tasklet_hi_enable(struct tasklet_struct *t);
 
 extern void tasklet_kill(struct tasklet_struct *t);
 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
@@ -592,6 +605,12 @@
 	tasklet_kill(&ttimer->tasklet);
 }
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+extern void softirq_early_init(void);
+#else
+static inline void softirq_early_init(void) { }
+#endif
+
 /*
  * Autoprobing for irqs:
  *
diff -Nur linux-3.18.12.orig/include/linux/irqdesc.h linux-3.18.12/include/linux/irqdesc.h
--- linux-3.18.12.orig/include/linux/irqdesc.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/irqdesc.h	2015-04-26 13:32:22.415684003 -0500
@@ -63,6 +63,7 @@
 	unsigned int		irqs_unhandled;
 	atomic_t		threads_handled;
 	int			threads_handled_last;
+	u64			random_ip;
 	raw_spinlock_t		lock;
 	struct cpumask		*percpu_enabled;
 #ifdef CONFIG_SMP
diff -Nur linux-3.18.12.orig/include/linux/irqflags.h linux-3.18.12/include/linux/irqflags.h
--- linux-3.18.12.orig/include/linux/irqflags.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/irqflags.h	2015-04-26 13:32:22.415684003 -0500
@@ -25,8 +25,6 @@
 # define trace_softirqs_enabled(p)	((p)->softirqs_enabled)
 # define trace_hardirq_enter()	do { current->hardirq_context++; } while (0)
 # define trace_hardirq_exit()	do { current->hardirq_context--; } while (0)
-# define lockdep_softirq_enter()	do { current->softirq_context++; } while (0)
-# define lockdep_softirq_exit()	do { current->softirq_context--; } while (0)
 # define INIT_TRACE_IRQFLAGS	.softirqs_enabled = 1,
 #else
 # define trace_hardirqs_on()		do { } while (0)
@@ -39,9 +37,15 @@
 # define trace_softirqs_enabled(p)	0
 # define trace_hardirq_enter()		do { } while (0)
 # define trace_hardirq_exit()		do { } while (0)
+# define INIT_TRACE_IRQFLAGS
+#endif
+
+#if defined(CONFIG_TRACE_IRQFLAGS) && !defined(CONFIG_PREEMPT_RT_FULL)
+# define lockdep_softirq_enter() do { current->softirq_context++; } while (0)
+# define lockdep_softirq_exit()	 do { current->softirq_context--; } while (0)
+#else
 # define lockdep_softirq_enter()	do { } while (0)
 # define lockdep_softirq_exit()		do { } while (0)
-# define INIT_TRACE_IRQFLAGS
 #endif
 
 #if defined(CONFIG_IRQSOFF_TRACER) || \
@@ -147,4 +151,23 @@
 
 #endif /* CONFIG_TRACE_IRQFLAGS_SUPPORT */
 
+/*
+ * local_irq* variants depending on RT/!RT
+ */
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define local_irq_disable_nort()	do { } while (0)
+# define local_irq_enable_nort()	do { } while (0)
+# define local_irq_save_nort(flags)	local_save_flags(flags)
+# define local_irq_restore_nort(flags)	(void)(flags)
+# define local_irq_disable_rt()		local_irq_disable()
+# define local_irq_enable_rt()		local_irq_enable()
+#else
+# define local_irq_disable_nort()	local_irq_disable()
+# define local_irq_enable_nort()	local_irq_enable()
+# define local_irq_save_nort(flags)	local_irq_save(flags)
+# define local_irq_restore_nort(flags)	local_irq_restore(flags)
+# define local_irq_disable_rt()		do { } while (0)
+# define local_irq_enable_rt()		do { } while (0)
+#endif
+
 #endif
diff -Nur linux-3.18.12.orig/include/linux/irq.h linux-3.18.12/include/linux/irq.h
--- linux-3.18.12.orig/include/linux/irq.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/irq.h	2015-04-26 13:32:22.415684003 -0500
@@ -73,6 +73,7 @@
  * IRQ_IS_POLLED		- Always polled by another interrupt. Exclude
  *				  it from the spurious interrupt detection
  *				  mechanism and from core side polling.
+ * IRQ_NO_SOFTIRQ_CALL		- No softirq processing in the irq thread context (RT)
  */
 enum {
 	IRQ_TYPE_NONE		= 0x00000000,
@@ -98,13 +99,14 @@
 	IRQ_NOTHREAD		= (1 << 16),
 	IRQ_PER_CPU_DEVID	= (1 << 17),
 	IRQ_IS_POLLED		= (1 << 18),
+	IRQ_NO_SOFTIRQ_CALL     = (1 << 19),
 };
 
 #define IRQF_MODIFY_MASK	\
 	(IRQ_TYPE_SENSE_MASK | IRQ_NOPROBE | IRQ_NOREQUEST | \
 	 IRQ_NOAUTOEN | IRQ_MOVE_PCNTXT | IRQ_LEVEL | IRQ_NO_BALANCING | \
 	 IRQ_PER_CPU | IRQ_NESTED_THREAD | IRQ_NOTHREAD | IRQ_PER_CPU_DEVID | \
-	 IRQ_IS_POLLED)
+	 IRQ_IS_POLLED | IRQ_NO_SOFTIRQ_CALL)
 
 #define IRQ_NO_BALANCING_MASK	(IRQ_PER_CPU | IRQ_NO_BALANCING)
 
diff -Nur linux-3.18.12.orig/include/linux/irq_work.h linux-3.18.12/include/linux/irq_work.h
--- linux-3.18.12.orig/include/linux/irq_work.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/irq_work.h	2015-04-26 13:32:22.415684003 -0500
@@ -16,6 +16,7 @@
 #define IRQ_WORK_BUSY		2UL
 #define IRQ_WORK_FLAGS		3UL
 #define IRQ_WORK_LAZY		4UL /* Doesn't want IPI, wait for tick */
+#define IRQ_WORK_HARD_IRQ	8UL /* Run hard IRQ context, even on RT */
 
 struct irq_work {
 	unsigned long flags;
diff -Nur linux-3.18.12.orig/include/linux/jbd_common.h linux-3.18.12/include/linux/jbd_common.h
--- linux-3.18.12.orig/include/linux/jbd_common.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/jbd_common.h	2015-04-26 13:32:22.415684003 -0500
@@ -15,32 +15,56 @@
 
 static inline void jbd_lock_bh_state(struct buffer_head *bh)
 {
+#ifndef CONFIG_PREEMPT_RT_BASE
 	bit_spin_lock(BH_State, &bh->b_state);
+#else
+	spin_lock(&bh->b_state_lock);
+#endif
 }
 
 static inline int jbd_trylock_bh_state(struct buffer_head *bh)
 {
+#ifndef CONFIG_PREEMPT_RT_BASE
 	return bit_spin_trylock(BH_State, &bh->b_state);
+#else
+	return spin_trylock(&bh->b_state_lock);
+#endif
 }
 
 static inline int jbd_is_locked_bh_state(struct buffer_head *bh)
 {
+#ifndef CONFIG_PREEMPT_RT_BASE
 	return bit_spin_is_locked(BH_State, &bh->b_state);
+#else
+	return spin_is_locked(&bh->b_state_lock);
+#endif
 }
 
 static inline void jbd_unlock_bh_state(struct buffer_head *bh)
 {
+#ifndef CONFIG_PREEMPT_RT_BASE
 	bit_spin_unlock(BH_State, &bh->b_state);
+#else
+	spin_unlock(&bh->b_state_lock);
+#endif
 }
 
 static inline void jbd_lock_bh_journal_head(struct buffer_head *bh)
 {
+#ifndef CONFIG_PREEMPT_RT_BASE
 	bit_spin_lock(BH_JournalHead, &bh->b_state);
+#else
+	spin_lock(&bh->b_journal_head_lock);
+#endif
 }
 
 static inline void jbd_unlock_bh_journal_head(struct buffer_head *bh)
 {
+#ifndef CONFIG_PREEMPT_RT_BASE
 	bit_spin_unlock(BH_JournalHead, &bh->b_state);
+#else
+	spin_unlock(&bh->b_journal_head_lock);
+#endif
 }
 
 #endif
diff -Nur linux-3.18.12.orig/include/linux/jump_label.h linux-3.18.12/include/linux/jump_label.h
--- linux-3.18.12.orig/include/linux/jump_label.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/jump_label.h	2015-04-26 13:32:22.419684003 -0500
@@ -55,7 +55,8 @@
 				    "%s used before call to jump_label_init", \
 				    __func__)
 
-#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
+#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) && \
+	!defined(CONFIG_PREEMPT_BASE)
 
 struct static_key {
 	atomic_t enabled;
diff -Nur linux-3.18.12.orig/include/linux/kdb.h linux-3.18.12/include/linux/kdb.h
--- linux-3.18.12.orig/include/linux/kdb.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/kdb.h	2015-04-26 13:32:22.419684003 -0500
@@ -116,7 +116,7 @@
 extern __printf(1, 0) int vkdb_printf(const char *fmt, va_list args);
 extern __printf(1, 2) int kdb_printf(const char *, ...);
 typedef __printf(1, 2) int (*kdb_printf_t)(const char *, ...);
-
+#define in_kdb_printk() (kdb_trap_printk)
 extern void kdb_init(int level);
 
 /* Access to kdb specific polling devices */
@@ -151,6 +151,7 @@
 extern int kdb_unregister(char *);
 #else /* ! CONFIG_KGDB_KDB */
 static inline __printf(1, 2) int kdb_printf(const char *fmt, ...) { return 0; }
+#define in_kdb_printk() (0)
 static inline void kdb_init(int level) {}
 static inline int kdb_register(char *cmd, kdb_func_t func, char *usage,
 			       char *help, short minlen) { return 0; }
diff -Nur linux-3.18.12.orig/include/linux/kernel.h linux-3.18.12/include/linux/kernel.h
--- linux-3.18.12.orig/include/linux/kernel.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/kernel.h	2015-04-26 13:32:22.419684003 -0500
@@ -451,6 +451,7 @@
 	SYSTEM_HALT,
 	SYSTEM_POWER_OFF,
 	SYSTEM_RESTART,
+	SYSTEM_SUSPEND,
 } system_state;
 
 #define TAINT_PROPRIETARY_MODULE	0
diff -Nur linux-3.18.12.orig/include/linux/kvm_host.h linux-3.18.12/include/linux/kvm_host.h
--- linux-3.18.12.orig/include/linux/kvm_host.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/kvm_host.h	2015-04-26 13:32:22.419684003 -0500
@@ -244,7 +244,7 @@
 
 	int fpu_active;
 	int guest_fpu_loaded, guest_xcr0_loaded;
-	wait_queue_head_t wq;
+	struct swait_head wq;
 	struct pid *pid;
 	int sigset_active;
 	sigset_t sigset;
@@ -687,7 +687,7 @@
 }
 #endif
 
-static inline wait_queue_head_t *kvm_arch_vcpu_wq(struct kvm_vcpu *vcpu)
+static inline struct swait_head *kvm_arch_vcpu_wq(struct kvm_vcpu *vcpu)
 {
 #ifdef __KVM_HAVE_ARCH_WQP
 	return vcpu->arch.wqp;
diff -Nur linux-3.18.12.orig/include/linux/lglock.h linux-3.18.12/include/linux/lglock.h
--- linux-3.18.12.orig/include/linux/lglock.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/lglock.h	2015-04-26 13:32:22.419684003 -0500
@@ -34,22 +34,39 @@
 #endif
 
 struct lglock {
+#ifndef CONFIG_PREEMPT_RT_FULL
 	arch_spinlock_t __percpu *lock;
+#else
+	struct rt_mutex __percpu *lock;
+#endif
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 	struct lock_class_key lock_key;
 	struct lockdep_map    lock_dep_map;
 #endif
 };
 
-#define DEFINE_LGLOCK(name)						\
+#ifndef CONFIG_PREEMPT_RT_FULL
+# define DEFINE_LGLOCK(name)						\
 	static DEFINE_PER_CPU(arch_spinlock_t, name ## _lock)		\
 	= __ARCH_SPIN_LOCK_UNLOCKED;					\
 	struct lglock name = { .lock = &name ## _lock }
 
-#define DEFINE_STATIC_LGLOCK(name)					\
+# define DEFINE_STATIC_LGLOCK(name)					\
 	static DEFINE_PER_CPU(arch_spinlock_t, name ## _lock)		\
 	= __ARCH_SPIN_LOCK_UNLOCKED;					\
 	static struct lglock name = { .lock = &name ## _lock }
+#else
+
+# define DEFINE_LGLOCK(name)						\
+	static DEFINE_PER_CPU(struct rt_mutex, name ## _lock)		\
+	= __RT_MUTEX_INITIALIZER( name ## _lock);			\
+	struct lglock name = { .lock = &name ## _lock }
+
+# define DEFINE_STATIC_LGLOCK(name)					\
+	static DEFINE_PER_CPU(struct rt_mutex, name ## _lock)		\
+	= __RT_MUTEX_INITIALIZER( name ## _lock);			\
+	static struct lglock name = { .lock = &name ## _lock }
+#endif
 
 void lg_lock_init(struct lglock *lg, char *name);
 void lg_local_lock(struct lglock *lg);
@@ -59,6 +76,12 @@
 void lg_global_lock(struct lglock *lg);
 void lg_global_unlock(struct lglock *lg);
 
+#ifndef CONFIG_PREEMPT_RT_FULL
+#define lg_global_trylock_relax(name)	lg_global_lock(name)
+#else
+void lg_global_trylock_relax(struct lglock *lg);
+#endif
+
 #else
 /* When !CONFIG_SMP, map lglock to spinlock */
 #define lglock spinlock
diff -Nur linux-3.18.12.orig/include/linux/list_bl.h linux-3.18.12/include/linux/list_bl.h
--- linux-3.18.12.orig/include/linux/list_bl.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/list_bl.h	2015-04-26 13:32:22.419684003 -0500
@@ -2,6 +2,7 @@
 #define _LINUX_LIST_BL_H
 
 #include <linux/list.h>
+#include <linux/spinlock.h>
 #include <linux/bit_spinlock.h>
 
 /*
@@ -32,13 +33,22 @@
 
 struct hlist_bl_head {
 	struct hlist_bl_node *first;
+#ifdef CONFIG_PREEMPT_RT_BASE
+	raw_spinlock_t lock;
+#endif
 };
 
 struct hlist_bl_node {
 	struct hlist_bl_node *next, **pprev;
 };
-#define INIT_HLIST_BL_HEAD(ptr) \
-	((ptr)->first = NULL)
+
+static inline void INIT_HLIST_BL_HEAD(struct hlist_bl_head *h)
+{
+	h->first = NULL;
+#ifdef CONFIG_PREEMPT_RT_BASE
+	raw_spin_lock_init(&h->lock);
+#endif
+}
 
 static inline void INIT_HLIST_BL_NODE(struct hlist_bl_node *h)
 {
@@ -117,12 +127,26 @@
 
 static inline void hlist_bl_lock(struct hlist_bl_head *b)
 {
+#ifndef CONFIG_PREEMPT_RT_BASE
 	bit_spin_lock(0, (unsigned long *)b);
+#else
+	raw_spin_lock(&b->lock);
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+	__set_bit(0, (unsigned long *)b);
+#endif
+#endif
 }
 
 static inline void hlist_bl_unlock(struct hlist_bl_head *b)
 {
+#ifndef CONFIG_PREEMPT_RT_BASE
 	__bit_spin_unlock(0, (unsigned long *)b);
+#else
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+	__clear_bit(0, (unsigned long *)b);
+#endif
+	raw_spin_unlock(&b->lock);
+#endif
 }
 
 static inline bool hlist_bl_is_locked(struct hlist_bl_head *b)
diff -Nur linux-3.18.12.orig/include/linux/locallock.h linux-3.18.12/include/linux/locallock.h
--- linux-3.18.12.orig/include/linux/locallock.h	1969-12-31 18:00:00.000000000 -0600
+++ linux-3.18.12/include/linux/locallock.h	2015-04-26 13:32:22.419684003 -0500
@@ -0,0 +1,270 @@
+#ifndef _LINUX_LOCALLOCK_H
+#define _LINUX_LOCALLOCK_H
+
+#include <linux/percpu.h>
+#include <linux/spinlock.h>
+
+#ifdef CONFIG_PREEMPT_RT_BASE
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+# define LL_WARN(cond)	WARN_ON(cond)
+#else
+# define LL_WARN(cond)	do { } while (0)
+#endif
+
+/*
+ * per cpu lock based substitute for local_irq_*()
+ */
+struct local_irq_lock {
+	spinlock_t		lock;
+	struct task_struct	*owner;
+	int			nestcnt;
+	unsigned long		flags;
+};
+
+#define DEFINE_LOCAL_IRQ_LOCK(lvar)					\
+	DEFINE_PER_CPU(struct local_irq_lock, lvar) = {			\
+		.lock = __SPIN_LOCK_UNLOCKED((lvar).lock) }
+
+#define DECLARE_LOCAL_IRQ_LOCK(lvar)					\
+	DECLARE_PER_CPU(struct local_irq_lock, lvar)
+
+#define local_irq_lock_init(lvar)					\
+	do {								\
+		int __cpu;						\
+		for_each_possible_cpu(__cpu)				\
+			spin_lock_init(&per_cpu(lvar, __cpu).lock);	\
+	} while (0)
+
+/*
+ * spin_lock|trylock|unlock_local flavour that does not migrate disable
+ * used for __local_lock|trylock|unlock where get_local_var/put_local_var
+ * already takes care of the migrate_disable/enable
+ * for CONFIG_PREEMPT_BASE map to the normal spin_* calls.
+ */
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define spin_lock_local(lock)			rt_spin_lock(lock)
+# define spin_trylock_local(lock)		rt_spin_trylock(lock)
+# define spin_unlock_local(lock)		rt_spin_unlock(lock)
+#else
+# define spin_lock_local(lock)			spin_lock(lock)
+# define spin_trylock_local(lock)		spin_trylock(lock)
+# define spin_unlock_local(lock)		spin_unlock(lock)
+#endif
+
+static inline void __local_lock(struct local_irq_lock *lv)
+{
+	if (lv->owner != current) {
+		spin_lock_local(&lv->lock);
+		LL_WARN(lv->owner);
+		LL_WARN(lv->nestcnt);
+		lv->owner = current;
+	}
+	lv->nestcnt++;
+}
+
+#define local_lock(lvar)					\
+	do { __local_lock(&get_local_var(lvar)); } while (0)
+
+static inline int __local_trylock(struct local_irq_lock *lv)
+{
+	if (lv->owner != current && spin_trylock_local(&lv->lock)) {
+		LL_WARN(lv->owner);
+		LL_WARN(lv->nestcnt);
+		lv->owner = current;
+		lv->nestcnt = 1;
+		return 1;
+	}
+	return 0;
+}
+
+#define local_trylock(lvar)						\
+	({								\
+		int __locked;						\
+		__locked = __local_trylock(&get_local_var(lvar));	\
+		if (!__locked)						\
+			put_local_var(lvar);				\
+		__locked;						\
+	})
+
+static inline void __local_unlock(struct local_irq_lock *lv)
+{
+	LL_WARN(lv->nestcnt == 0);
+	LL_WARN(lv->owner != current);
+	if (--lv->nestcnt)
+		return;
+
+	lv->owner = NULL;
+	spin_unlock_local(&lv->lock);
+}
+
+#define local_unlock(lvar)					\
+	do {							\
+		__local_unlock(&__get_cpu_var(lvar));		\
+		put_local_var(lvar);				\
+	} while (0)
+
+static inline void __local_lock_irq(struct local_irq_lock *lv)
+{
+	spin_lock_irqsave(&lv->lock, lv->flags);
+	LL_WARN(lv->owner);
+	LL_WARN(lv->nestcnt);
+	lv->owner = current;
+	lv->nestcnt = 1;
+}
+
+#define local_lock_irq(lvar)						\
+	do { __local_lock_irq(&get_local_var(lvar)); } while (0)
+
+#define local_lock_irq_on(lvar, cpu)					\
+	do { __local_lock_irq(&per_cpu(lvar, cpu)); } while (0)
+
+static inline void __local_unlock_irq(struct local_irq_lock *lv)
+{
+	LL_WARN(!lv->nestcnt);
+	LL_WARN(lv->owner != current);
+	lv->owner = NULL;
+	lv->nestcnt = 0;
+	spin_unlock_irq(&lv->lock);
+}
+
+#define local_unlock_irq(lvar)						\
+	do {								\
+		__local_unlock_irq(&__get_cpu_var(lvar));		\
+		put_local_var(lvar);					\
+	} while (0)
+
+#define local_unlock_irq_on(lvar, cpu)					\
+	do {								\
+		__local_unlock_irq(&per_cpu(lvar, cpu));		\
+	} while (0)
+
+static inline int __local_lock_irqsave(struct local_irq_lock *lv)
+{
+	if (lv->owner != current) {
+		__local_lock_irq(lv);
+		return 0;
+	} else {
+		lv->nestcnt++;
+		return 1;
+	}
+}
+
+#define local_lock_irqsave(lvar, _flags)				\
+	do {								\
+		if (__local_lock_irqsave(&get_local_var(lvar)))		\
+			put_local_var(lvar);				\
+		_flags = __get_cpu_var(lvar).flags;			\
+	} while (0)
+
+#define local_lock_irqsave_on(lvar, _flags, cpu)			\
+	do {								\
+		__local_lock_irqsave(&per_cpu(lvar, cpu));		\
+		_flags = per_cpu(lvar, cpu).flags;			\
+	} while (0)
+
+static inline int __local_unlock_irqrestore(struct local_irq_lock *lv,
+					    unsigned long flags)
+{
+	LL_WARN(!lv->nestcnt);
+	LL_WARN(lv->owner != current);
+	if (--lv->nestcnt)
+		return 0;
+
+	lv->owner = NULL;
+	spin_unlock_irqrestore(&lv->lock, lv->flags);
+	return 1;
+}
+
+#define local_unlock_irqrestore(lvar, flags)				\
+	do {								\
+		if (__local_unlock_irqrestore(&__get_cpu_var(lvar), flags)) \
+			put_local_var(lvar);				\
+	} while (0)
+
+#define local_unlock_irqrestore_on(lvar, flags, cpu)			\
+	do {								\
+		__local_unlock_irqrestore(&per_cpu(lvar, cpu), flags);	\
+	} while (0)
+
+#define local_spin_trylock_irq(lvar, lock)				\
+	({								\
+		int __locked;						\
+		local_lock_irq(lvar);					\
+		__locked = spin_trylock(lock);				\
+		if (!__locked)						\
+			local_unlock_irq(lvar);				\
+		__locked;						\
+	})
+
+#define local_spin_lock_irq(lvar, lock)					\
+	do {								\
+		local_lock_irq(lvar);					\
+		spin_lock(lock);					\
+	} while (0)
+
+#define local_spin_unlock_irq(lvar, lock)				\
+	do {								\
+		spin_unlock(lock);					\
+		local_unlock_irq(lvar);					\
+	} while (0)
+
+#define local_spin_lock_irqsave(lvar, lock, flags)			\
+	do {								\
+		local_lock_irqsave(lvar, flags);			\
+		spin_lock(lock);					\
+	} while (0)
+
+#define local_spin_unlock_irqrestore(lvar, lock, flags)			\
+	do {								\
+		spin_unlock(lock);					\
+		local_unlock_irqrestore(lvar, flags);			\
+	} while (0)
+
+#define get_locked_var(lvar, var)					\
+	(*({								\
+		local_lock(lvar);					\
+		&__get_cpu_var(var);					\
+	}))
+
+#define put_locked_var(lvar, var)	local_unlock(lvar);
+
+#define local_lock_cpu(lvar)						\
+	({								\
+		local_lock(lvar);					\
+		smp_processor_id();					\
+	})
+
+#define local_unlock_cpu(lvar)			local_unlock(lvar)
+
+#else /* PREEMPT_RT_BASE */
+
+#define DEFINE_LOCAL_IRQ_LOCK(lvar)		__typeof__(const int) lvar
+#define DECLARE_LOCAL_IRQ_LOCK(lvar)		extern __typeof__(const int) lvar
+
+static inline void local_irq_lock_init(int lvar) { }
+
+#define local_lock(lvar)			preempt_disable()
+#define local_unlock(lvar)			preempt_enable()
+#define local_lock_irq(lvar)			local_irq_disable()
+#define local_unlock_irq(lvar)			local_irq_enable()
+#define local_lock_irqsave(lvar, flags)		local_irq_save(flags)
+#define local_unlock_irqrestore(lvar, flags)	local_irq_restore(flags)
+
+#define local_spin_trylock_irq(lvar, lock)	spin_trylock_irq(lock)
+#define local_spin_lock_irq(lvar, lock)		spin_lock_irq(lock)
+#define local_spin_unlock_irq(lvar, lock)	spin_unlock_irq(lock)
+#define local_spin_lock_irqsave(lvar, lock, flags)	\
+	spin_lock_irqsave(lock, flags)
+#define local_spin_unlock_irqrestore(lvar, lock, flags)	\
+	spin_unlock_irqrestore(lock, flags)
+
+#define get_locked_var(lvar, var)		get_cpu_var(var)
+#define put_locked_var(lvar, var)		put_cpu_var(var)
+
+#define local_lock_cpu(lvar)			get_cpu()
+#define local_unlock_cpu(lvar)			put_cpu()
+
+#endif
+
+#endif
diff -Nur linux-3.18.12.orig/include/linux/mm_types.h linux-3.18.12/include/linux/mm_types.h
--- linux-3.18.12.orig/include/linux/mm_types.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/mm_types.h	2015-04-26 13:32:22.419684003 -0500
@@ -11,6 +11,7 @@
 #include <linux/completion.h>
 #include <linux/cpumask.h>
 #include <linux/page-debug-flags.h>
+#include <linux/rcupdate.h>
 #include <linux/uprobes.h>
 #include <linux/page-flags-layout.h>
 #include <asm/page.h>
@@ -454,6 +455,9 @@
 	bool tlb_flush_pending;
 #endif
 	struct uprobes_state uprobes_state;
+#ifdef CONFIG_PREEMPT_RT_BASE
+	struct rcu_head delayed_drop;
+#endif
 };
 
 static inline void mm_init_cpumask(struct mm_struct *mm)
diff -Nur linux-3.18.12.orig/include/linux/mutex.h linux-3.18.12/include/linux/mutex.h
--- linux-3.18.12.orig/include/linux/mutex.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/mutex.h	2015-04-26 13:32:22.419684003 -0500
@@ -19,6 +19,17 @@
 #include <asm/processor.h>
 #include <linux/osq_lock.h>
 
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define __DEP_MAP_MUTEX_INITIALIZER(lockname) \
+	, .dep_map = { .name = #lockname }
+#else
+# define __DEP_MAP_MUTEX_INITIALIZER(lockname)
+#endif
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+# include <linux/mutex_rt.h>
+#else
+
 /*
  * Simple, straightforward mutexes with strict semantics:
  *
@@ -100,13 +111,6 @@
 static inline void mutex_destroy(struct mutex *lock) {}
 #endif
 
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-# define __DEP_MAP_MUTEX_INITIALIZER(lockname) \
-		, .dep_map = { .name = #lockname }
-#else
-# define __DEP_MAP_MUTEX_INITIALIZER(lockname)
-#endif
-
 #define __MUTEX_INITIALIZER(lockname) \
 		{ .count = ATOMIC_INIT(1) \
 		, .wait_lock = __SPIN_LOCK_UNLOCKED(lockname.wait_lock) \
@@ -174,6 +178,8 @@
 extern int mutex_trylock(struct mutex *lock);
 extern void mutex_unlock(struct mutex *lock);
 
+#endif /* !PREEMPT_RT_FULL */
+
 extern int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock);
 
 #endif /* __LINUX_MUTEX_H */
diff -Nur linux-3.18.12.orig/include/linux/mutex_rt.h linux-3.18.12/include/linux/mutex_rt.h
--- linux-3.18.12.orig/include/linux/mutex_rt.h	1969-12-31 18:00:00.000000000 -0600
+++ linux-3.18.12/include/linux/mutex_rt.h	2015-04-26 13:32:22.419684003 -0500
@@ -0,0 +1,84 @@
+#ifndef __LINUX_MUTEX_RT_H
+#define __LINUX_MUTEX_RT_H
+
+#ifndef __LINUX_MUTEX_H
+#error "Please include mutex.h"
+#endif
+
+#include <linux/rtmutex.h>
+
+/* FIXME: Just for __lockfunc */
+#include <linux/spinlock.h>
+
+struct mutex {
+	struct rt_mutex		lock;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	struct lockdep_map	dep_map;
+#endif
+};
+
+#define __MUTEX_INITIALIZER(mutexname)					\
+	{								\
+		.lock = __RT_MUTEX_INITIALIZER(mutexname.lock)		\
+		__DEP_MAP_MUTEX_INITIALIZER(mutexname)			\
+	}
+
+#define DEFINE_MUTEX(mutexname)						\
+	struct mutex mutexname = __MUTEX_INITIALIZER(mutexname)
+
+extern void __mutex_do_init(struct mutex *lock, const char *name, struct lock_class_key *key);
+extern void __lockfunc _mutex_lock(struct mutex *lock);
+extern int __lockfunc _mutex_lock_interruptible(struct mutex *lock);
+extern int __lockfunc _mutex_lock_killable(struct mutex *lock);
+extern void __lockfunc _mutex_lock_nested(struct mutex *lock, int subclass);
+extern void __lockfunc _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest_lock);
+extern int __lockfunc _mutex_lock_interruptible_nested(struct mutex *lock, int subclass);
+extern int __lockfunc _mutex_lock_killable_nested(struct mutex *lock, int subclass);
+extern int __lockfunc _mutex_trylock(struct mutex *lock);
+extern void __lockfunc _mutex_unlock(struct mutex *lock);
+
+#define mutex_is_locked(l)		rt_mutex_is_locked(&(l)->lock)
+#define mutex_lock(l)			_mutex_lock(l)
+#define mutex_lock_interruptible(l)	_mutex_lock_interruptible(l)
+#define mutex_lock_killable(l)		_mutex_lock_killable(l)
+#define mutex_trylock(l)		_mutex_trylock(l)
+#define mutex_unlock(l)			_mutex_unlock(l)
+#define mutex_destroy(l)		rt_mutex_destroy(&(l)->lock)
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define mutex_lock_nested(l, s)	_mutex_lock_nested(l, s)
+# define mutex_lock_interruptible_nested(l, s) \
+					_mutex_lock_interruptible_nested(l, s)
+# define mutex_lock_killable_nested(l, s) \
+					_mutex_lock_killable_nested(l, s)
+
+# define mutex_lock_nest_lock(lock, nest_lock)				\
+do {									\
+	typecheck(struct lockdep_map *, &(nest_lock)->dep_map);		\
+	_mutex_lock_nest_lock(lock, &(nest_lock)->dep_map);		\
+} while (0)
+
+#else
+# define mutex_lock_nested(l, s)	_mutex_lock(l)
+# define mutex_lock_interruptible_nested(l, s) \
+					_mutex_lock_interruptible(l)
+# define mutex_lock_killable_nested(l, s) \
+					_mutex_lock_killable(l)
+# define mutex_lock_nest_lock(lock, nest_lock) mutex_lock(lock)
+#endif
+
+# define mutex_init(mutex)				\
+do {							\
+	static struct lock_class_key __key;		\
+							\
+	rt_mutex_init(&(mutex)->lock);			\
+	__mutex_do_init((mutex), #mutex, &__key);	\
+} while (0)
+
+# define __mutex_init(mutex, name, key)			\
+do {							\
+	rt_mutex_init(&(mutex)->lock);			\
+	__mutex_do_init((mutex), name, key);		\
+} while (0)
+
+#endif
diff -Nur linux-3.18.12.orig/include/linux/netdevice.h linux-3.18.12/include/linux/netdevice.h
--- linux-3.18.12.orig/include/linux/netdevice.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/netdevice.h	2015-04-26 13:32:22.419684003 -0500
@@ -2345,6 +2345,7 @@
 	unsigned int		dropped;
 	struct sk_buff_head	input_pkt_queue;
 	struct napi_struct	backlog;
+	struct sk_buff_head	tofree_queue;
 
 #ifdef CONFIG_NET_FLOW_LIMIT
 	struct sd_flow_limit __rcu *flow_limit;
diff -Nur linux-3.18.12.orig/include/linux/netfilter/x_tables.h linux-3.18.12/include/linux/netfilter/x_tables.h
--- linux-3.18.12.orig/include/linux/netfilter/x_tables.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/netfilter/x_tables.h	2015-04-26 13:32:22.419684003 -0500
@@ -3,6 +3,7 @@
 
 
 #include <linux/netdevice.h>
+#include <linux/locallock.h>
 #include <uapi/linux/netfilter/x_tables.h>
 
 /**
@@ -282,6 +283,8 @@
  */
 DECLARE_PER_CPU(seqcount_t, xt_recseq);
 
+DECLARE_LOCAL_IRQ_LOCK(xt_write_lock);
+
 /**
  * xt_write_recseq_begin - start of a write section
  *
@@ -296,6 +299,9 @@
 {
 	unsigned int addend;
 
+	/* RT protection */
+	local_lock(xt_write_lock);
+
 	/*
 	 * Low order bit of sequence is set if we already
 	 * called xt_write_recseq_begin().
@@ -326,6 +332,7 @@
 	/* this is kind of a write_seqcount_end(), but addend is 0 or 1 */
 	smp_wmb();
 	__this_cpu_add(xt_recseq.sequence, addend);
+	local_unlock(xt_write_lock);
 }
 
 /*
diff -Nur linux-3.18.12.orig/include/linux/notifier.h linux-3.18.12/include/linux/notifier.h
--- linux-3.18.12.orig/include/linux/notifier.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/notifier.h	2015-04-26 13:32:22.419684003 -0500
@@ -6,7 +6,7 @@
  *
  *				Alan Cox <Alan.Cox@linux.org>
  */
- 
+
 #ifndef _LINUX_NOTIFIER_H
 #define _LINUX_NOTIFIER_H
 #include <linux/errno.h>
@@ -42,9 +42,7 @@
  * in srcu_notifier_call_chain(): no cache bounces and no memory barriers.
  * As compensation, srcu_notifier_chain_unregister() is rather expensive.
  * SRCU notifier chains should be used when the chain will be called very
- * often but notifier_blocks will seldom be removed.  Also, SRCU notifier
- * chains are slightly more difficult to use because they require special
- * runtime initialization.
+ * often but notifier_blocks will seldom be removed.
  */
 
 typedef	int (*notifier_fn_t)(struct notifier_block *nb,
@@ -88,7 +86,7 @@
 		(name)->head = NULL;		\
 	} while (0)
 
-/* srcu_notifier_heads must be initialized and cleaned up dynamically */
+/* srcu_notifier_heads must be cleaned up dynamically */
 extern void srcu_init_notifier_head(struct srcu_notifier_head *nh);
 #define srcu_cleanup_notifier_head(name)	\
 		cleanup_srcu_struct(&(name)->srcu);
@@ -101,7 +99,13 @@
 		.head = NULL }
 #define RAW_NOTIFIER_INIT(name)	{				\
 		.head = NULL }
-/* srcu_notifier_heads cannot be initialized statically */
+
+#define SRCU_NOTIFIER_INIT(name, pcpu)				\
+	{							\
+		.mutex = __MUTEX_INITIALIZER(name.mutex),	\
+		.head = NULL,					\
+		.srcu = __SRCU_STRUCT_INIT(name.srcu, pcpu),	\
+	}
 
 #define ATOMIC_NOTIFIER_HEAD(name)				\
 	struct atomic_notifier_head name =			\
@@ -113,6 +117,18 @@
 	struct raw_notifier_head name =				\
 		RAW_NOTIFIER_INIT(name)
 
+#define _SRCU_NOTIFIER_HEAD(name, mod)				\
+	static DEFINE_PER_CPU(struct srcu_struct_array,		\
+			name##_head_srcu_array);		\
+	mod struct srcu_notifier_head name =			\
+			SRCU_NOTIFIER_INIT(name, name##_head_srcu_array)
+
+#define SRCU_NOTIFIER_HEAD(name)				\
+	_SRCU_NOTIFIER_HEAD(name, )
+
+#define SRCU_NOTIFIER_HEAD_STATIC(name)				\
+	_SRCU_NOTIFIER_HEAD(name, static)
+
 #ifdef __KERNEL__
 
 extern int atomic_notifier_chain_register(struct atomic_notifier_head *nh,
@@ -182,12 +198,12 @@
 
 /*
  *	Declared notifiers so far. I can imagine quite a few more chains
- *	over time (eg laptop power reset chains, reboot chain (to clean 
+ *	over time (eg laptop power reset chains, reboot chain (to clean
  *	device units up), device [un]mount chain, module load/unload chain,
- *	low memory chain, screenblank chain (for plug in modular screenblankers) 
+ *	low memory chain, screenblank chain (for plug in modular screenblankers)
  *	VC switch chains (for loadable kernel svgalib VC switch helpers) etc...
  */
- 
+
 /* CPU notfiers are defined in include/linux/cpu.h. */
 
 /* netdevice notifiers are defined in include/linux/netdevice.h */
diff -Nur linux-3.18.12.orig/include/linux/percpu.h linux-3.18.12/include/linux/percpu.h
--- linux-3.18.12.orig/include/linux/percpu.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/percpu.h	2015-04-26 13:32:22.419684003 -0500
@@ -23,6 +23,35 @@
 	 PERCPU_MODULE_RESERVE)
 #endif
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+
+#define get_local_var(var) (*({		\
+	       migrate_disable();	\
+	       &__get_cpu_var(var);	}))
+
+#define put_local_var(var) do {	\
+	(void)&(var);		\
+	migrate_enable();	\
+} while (0)
+
+# define get_local_ptr(var) ({		\
+		migrate_disable();	\
+		this_cpu_ptr(var);	})
+
+# define put_local_ptr(var) do {	\
+	(void)(var);			\
+	migrate_enable();		\
+} while (0)
+
+#else
+
+#define get_local_var(var)	get_cpu_var(var)
+#define put_local_var(var)	put_cpu_var(var)
+#define get_local_ptr(var)	get_cpu_ptr(var)
+#define put_local_ptr(var)	put_cpu_ptr(var)
+
+#endif
+
 /* minimum unit size, also is the maximum supported allocation size */
 #define PCPU_MIN_UNIT_SIZE		PFN_ALIGN(32 << 10)
 
diff -Nur linux-3.18.12.orig/include/linux/pid.h linux-3.18.12/include/linux/pid.h
--- linux-3.18.12.orig/include/linux/pid.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/pid.h	2015-04-26 13:32:22.419684003 -0500
@@ -2,6 +2,7 @@
 #define _LINUX_PID_H
 
 #include <linux/rcupdate.h>
+#include <linux/atomic.h>
 
 enum pid_type
 {
diff -Nur linux-3.18.12.orig/include/linux/preempt.h linux-3.18.12/include/linux/preempt.h
--- linux-3.18.12.orig/include/linux/preempt.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/preempt.h	2015-04-26 13:32:22.419684003 -0500
@@ -33,6 +33,20 @@
 #define preempt_count_inc() preempt_count_add(1)
 #define preempt_count_dec() preempt_count_sub(1)
 
+#ifdef CONFIG_PREEMPT_LAZY
+#define add_preempt_lazy_count(val)	do { preempt_lazy_count() += (val); } while (0)
+#define sub_preempt_lazy_count(val)	do { preempt_lazy_count() -= (val); } while (0)
+#define inc_preempt_lazy_count()	add_preempt_lazy_count(1)
+#define dec_preempt_lazy_count()	sub_preempt_lazy_count(1)
+#define preempt_lazy_count()		(current_thread_info()->preempt_lazy_count)
+#else
+#define add_preempt_lazy_count(val)	do { } while (0)
+#define sub_preempt_lazy_count(val)	do { } while (0)
+#define inc_preempt_lazy_count()	do { } while (0)
+#define dec_preempt_lazy_count()	do { } while (0)
+#define preempt_lazy_count()		(0)
+#endif
+
 #ifdef CONFIG_PREEMPT_COUNT
 
 #define preempt_disable() \
@@ -41,13 +55,25 @@
 	barrier(); \
 } while (0)
 
+#define preempt_lazy_disable() \
+do { \
+	inc_preempt_lazy_count(); \
+	barrier(); \
+} while (0)
+
 #define sched_preempt_enable_no_resched() \
 do { \
 	barrier(); \
 	preempt_count_dec(); \
 } while (0)
 
-#define preempt_enable_no_resched() sched_preempt_enable_no_resched()
+#ifdef CONFIG_PREEMPT_RT_BASE
+# define preempt_enable_no_resched() sched_preempt_enable_no_resched()
+# define preempt_check_resched_rt() preempt_check_resched()
+#else
+# define preempt_enable_no_resched() preempt_enable()
+# define preempt_check_resched_rt() barrier();
+#endif
 
 #ifdef CONFIG_PREEMPT
 #define preempt_enable() \
@@ -63,6 +89,13 @@
 		__preempt_schedule(); \
 } while (0)
 
+#define preempt_lazy_enable() \
+do { \
+	dec_preempt_lazy_count(); \
+	barrier(); \
+	preempt_check_resched(); \
+} while (0)
+
 #else
 #define preempt_enable() \
 do { \
@@ -121,6 +154,7 @@
 #define preempt_disable_notrace()		barrier()
 #define preempt_enable_no_resched_notrace()	barrier()
 #define preempt_enable_notrace()		barrier()
+#define preempt_check_resched_rt()		barrier()
 
 #endif /* CONFIG_PREEMPT_COUNT */
 
@@ -140,10 +174,31 @@
 } while (0)
 #define preempt_fold_need_resched() \
 do { \
-	if (tif_need_resched()) \
+	if (tif_need_resched_now()) \
 		set_preempt_need_resched(); \
 } while (0)
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define preempt_disable_rt()		preempt_disable()
+# define preempt_enable_rt()		preempt_enable()
+# define preempt_disable_nort()		barrier()
+# define preempt_enable_nort()		barrier()
+# ifdef CONFIG_SMP
+   extern void migrate_disable(void);
+   extern void migrate_enable(void);
+# else /* CONFIG_SMP */
+#  define migrate_disable()		barrier()
+#  define migrate_enable()		barrier()
+# endif /* CONFIG_SMP */
+#else
+# define preempt_disable_rt()		barrier()
+# define preempt_enable_rt()		barrier()
+# define preempt_disable_nort()		preempt_disable()
+# define preempt_enable_nort()		preempt_enable()
+# define migrate_disable()		preempt_disable()
+# define migrate_enable()		preempt_enable()
+#endif
+
 #ifdef CONFIG_PREEMPT_NOTIFIERS
 
 struct preempt_notifier;
diff -Nur linux-3.18.12.orig/include/linux/preempt_mask.h linux-3.18.12/include/linux/preempt_mask.h
--- linux-3.18.12.orig/include/linux/preempt_mask.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/preempt_mask.h	2015-04-26 13:32:22.419684003 -0500
@@ -44,16 +44,26 @@
 #define HARDIRQ_OFFSET	(1UL << HARDIRQ_SHIFT)
 #define NMI_OFFSET	(1UL << NMI_SHIFT)
 
-#define SOFTIRQ_DISABLE_OFFSET	(2 * SOFTIRQ_OFFSET)
+#ifndef CONFIG_PREEMPT_RT_FULL
+# define SOFTIRQ_DISABLE_OFFSET	(2 * SOFTIRQ_OFFSET)
+#else
+# define SOFTIRQ_DISABLE_OFFSET	(0)
+#endif
 
 #define PREEMPT_ACTIVE_BITS	1
 #define PREEMPT_ACTIVE_SHIFT	(NMI_SHIFT + NMI_BITS)
 #define PREEMPT_ACTIVE	(__IRQ_MASK(PREEMPT_ACTIVE_BITS) << PREEMPT_ACTIVE_SHIFT)
 
 #define hardirq_count()	(preempt_count() & HARDIRQ_MASK)
-#define softirq_count()	(preempt_count() & SOFTIRQ_MASK)
 #define irq_count()	(preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK \
 				 | NMI_MASK))
+#ifndef CONFIG_PREEMPT_RT_FULL
+# define softirq_count()	(preempt_count() & SOFTIRQ_MASK)
+# define in_serving_softirq()	(softirq_count() & SOFTIRQ_OFFSET)
+#else
+# define softirq_count()	(0UL)
+extern int in_serving_softirq(void);
+#endif
 
 /*
  * Are we doing bottom half or hardware interrupt processing?
@@ -64,7 +74,6 @@
 #define in_irq()		(hardirq_count())
 #define in_softirq()		(softirq_count())
 #define in_interrupt()		(irq_count())
-#define in_serving_softirq()	(softirq_count() & SOFTIRQ_OFFSET)
 
 /*
  * Are we in NMI context?
diff -Nur linux-3.18.12.orig/include/linux/printk.h linux-3.18.12/include/linux/printk.h
--- linux-3.18.12.orig/include/linux/printk.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/printk.h	2015-04-26 13:32:22.419684003 -0500
@@ -119,9 +119,11 @@
 extern asmlinkage __printf(1, 2)
 void early_printk(const char *fmt, ...);
 void early_vprintk(const char *fmt, va_list ap);
+extern void printk_kill(void);
 #else
 static inline __printf(1, 2) __cold
 void early_printk(const char *s, ...) { }
+static inline void printk_kill(void) { }
 #endif
 
 #ifdef CONFIG_PRINTK
@@ -155,7 +157,6 @@
 #define printk_ratelimit() __printk_ratelimit(__func__)
 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 				   unsigned int interval_msec);
-
 extern int printk_delay_msec;
 extern int dmesg_restrict;
 extern int kptr_restrict;
diff -Nur linux-3.18.12.orig/include/linux/radix-tree.h linux-3.18.12/include/linux/radix-tree.h
--- linux-3.18.12.orig/include/linux/radix-tree.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/radix-tree.h	2015-04-26 13:32:22.419684003 -0500
@@ -277,8 +277,13 @@
 unsigned int radix_tree_gang_lookup_slot(struct radix_tree_root *root,
 			void ***results, unsigned long *indices,
 			unsigned long first_index, unsigned int max_items);
+#ifndef CONFIG_PREEMPT_RT_FULL
 int radix_tree_preload(gfp_t gfp_mask);
 int radix_tree_maybe_preload(gfp_t gfp_mask);
+#else
+static inline int radix_tree_preload(gfp_t gm) { return 0; }
+static inline int radix_tree_maybe_preload(gfp_t gfp_mask) { return 0; }
+#endif
 void radix_tree_init(void);
 void *radix_tree_tag_set(struct radix_tree_root *root,
 			unsigned long index, unsigned int tag);
@@ -303,7 +308,7 @@
 
 static inline void radix_tree_preload_end(void)
 {
-	preempt_enable();
+	preempt_enable_nort();
 }
 
 /**
diff -Nur linux-3.18.12.orig/include/linux/random.h linux-3.18.12/include/linux/random.h
--- linux-3.18.12.orig/include/linux/random.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/random.h	2015-04-26 13:32:22.423684003 -0500
@@ -11,7 +11,7 @@
 extern void add_device_randomness(const void *, unsigned int);
 extern void add_input_randomness(unsigned int type, unsigned int code,
 				 unsigned int value);
-extern void add_interrupt_randomness(int irq, int irq_flags);
+extern void add_interrupt_randomness(int irq, int irq_flags, __u64 ip);
 
 extern void get_random_bytes(void *buf, int nbytes);
 extern void get_random_bytes_arch(void *buf, int nbytes);
diff -Nur linux-3.18.12.orig/include/linux/rcupdate.h linux-3.18.12/include/linux/rcupdate.h
--- linux-3.18.12.orig/include/linux/rcupdate.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/rcupdate.h	2015-04-26 13:32:22.423684003 -0500
@@ -147,6 +147,9 @@
 
 #endif /* #else #ifdef CONFIG_PREEMPT_RCU */
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+#define call_rcu_bh	call_rcu
+#else
 /**
  * call_rcu_bh() - Queue an RCU for invocation after a quicker grace period.
  * @head: structure to be used for queueing the RCU updates.
@@ -170,6 +173,7 @@
  */
 void call_rcu_bh(struct rcu_head *head,
 		 void (*func)(struct rcu_head *head));
+#endif
 
 /**
  * call_rcu_sched() - Queue an RCU for invocation after sched grace period.
@@ -231,6 +235,11 @@
  * types of kernel builds, the rcu_read_lock() nesting depth is unknowable.
  */
 #define rcu_preempt_depth() (current->rcu_read_lock_nesting)
+#ifndef CONFIG_PREEMPT_RT_FULL
+#define sched_rcu_preempt_depth()	rcu_preempt_depth()
+#else
+static inline int sched_rcu_preempt_depth(void) { return 0; }
+#endif
 
 #else /* #ifdef CONFIG_PREEMPT_RCU */
 
@@ -254,6 +263,8 @@
 	return 0;
 }
 
+#define sched_rcu_preempt_depth()	rcu_preempt_depth()
+
 #endif /* #else #ifdef CONFIG_PREEMPT_RCU */
 
 /* Internal to kernel */
@@ -430,7 +441,14 @@
 int debug_lockdep_rcu_enabled(void);
 
 int rcu_read_lock_held(void);
+#ifdef CONFIG_PREEMPT_RT_FULL
+static inline int rcu_read_lock_bh_held(void)
+{
+	return rcu_read_lock_held();
+}
+#else
 int rcu_read_lock_bh_held(void);
+#endif
 
 /**
  * rcu_read_lock_sched_held() - might we be in RCU-sched read-side critical section?
@@ -955,10 +973,14 @@
 static inline void rcu_read_lock_bh(void)
 {
 	local_bh_disable();
+#ifdef CONFIG_PREEMPT_RT_FULL
+	rcu_read_lock();
+#else
 	__acquire(RCU_BH);
 	rcu_lock_acquire(&rcu_bh_lock_map);
 	rcu_lockdep_assert(rcu_is_watching(),
 			   "rcu_read_lock_bh() used illegally while idle");
+#endif
 }
 
 /*
@@ -968,10 +990,14 @@
  */
 static inline void rcu_read_unlock_bh(void)
 {
+#ifdef CONFIG_PREEMPT_RT_FULL
+	rcu_read_unlock();
+#else
 	rcu_lockdep_assert(rcu_is_watching(),
 			   "rcu_read_unlock_bh() used illegally while idle");
 	rcu_lock_release(&rcu_bh_lock_map);
 	__release(RCU_BH);
+#endif
 	local_bh_enable();
 }
 
diff -Nur linux-3.18.12.orig/include/linux/rcutree.h linux-3.18.12/include/linux/rcutree.h
--- linux-3.18.12.orig/include/linux/rcutree.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/rcutree.h	2015-04-26 13:32:22.423684003 -0500
@@ -46,7 +46,11 @@
 	rcu_note_context_switch(cpu);
 }
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define synchronize_rcu_bh	synchronize_rcu
+#else
 void synchronize_rcu_bh(void);
+#endif
 void synchronize_sched_expedited(void);
 void synchronize_rcu_expedited(void);
 
@@ -74,7 +78,11 @@
 }
 
 void rcu_barrier(void);
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define rcu_barrier_bh                rcu_barrier
+#else
 void rcu_barrier_bh(void);
+#endif
 void rcu_barrier_sched(void);
 unsigned long get_state_synchronize_rcu(void);
 void cond_synchronize_rcu(unsigned long oldstate);
@@ -82,12 +90,10 @@
 extern unsigned long rcutorture_testseq;
 extern unsigned long rcutorture_vernum;
 long rcu_batches_completed(void);
-long rcu_batches_completed_bh(void);
 long rcu_batches_completed_sched(void);
 void show_rcu_gp_kthreads(void);
 
 void rcu_force_quiescent_state(void);
-void rcu_bh_force_quiescent_state(void);
 void rcu_sched_force_quiescent_state(void);
 
 void exit_rcu(void);
@@ -97,4 +103,12 @@
 
 bool rcu_is_watching(void);
 
+#ifndef CONFIG_PREEMPT_RT_FULL
+void rcu_bh_force_quiescent_state(void);
+long rcu_batches_completed_bh(void);
+#else
+# define rcu_bh_force_quiescent_state	rcu_force_quiescent_state
+# define rcu_batches_completed_bh	rcu_batches_completed
+#endif
+
 #endif /* __LINUX_RCUTREE_H */
diff -Nur linux-3.18.12.orig/include/linux/rtmutex.h linux-3.18.12/include/linux/rtmutex.h
--- linux-3.18.12.orig/include/linux/rtmutex.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/rtmutex.h	2015-04-26 13:32:22.423684003 -0500
@@ -14,10 +14,14 @@
 
 #include <linux/linkage.h>
 #include <linux/rbtree.h>
-#include <linux/spinlock_types.h>
+#include <linux/spinlock_types_raw.h>
 
 extern int max_lock_depth; /* for sysctl */
 
+#ifdef CONFIG_DEBUG_MUTEXES
+#include <linux/debug_locks.h>
+#endif
+
 /**
  * The rt_mutex structure
  *
@@ -31,8 +35,8 @@
 	struct rb_root          waiters;
 	struct rb_node          *waiters_leftmost;
 	struct task_struct	*owner;
-#ifdef CONFIG_DEBUG_RT_MUTEXES
 	int			save_state;
+#ifdef CONFIG_DEBUG_RT_MUTEXES
 	const char 		*name, *file;
 	int			line;
 	void			*magic;
@@ -55,22 +59,33 @@
 # define rt_mutex_debug_check_no_locks_held(task)	do { } while (0)
 #endif
 
+# define rt_mutex_init(mutex)					\
+	do {							\
+		raw_spin_lock_init(&(mutex)->wait_lock);	\
+		__rt_mutex_init(mutex, #mutex);			\
+	} while (0)
+
 #ifdef CONFIG_DEBUG_RT_MUTEXES
 # define __DEBUG_RT_MUTEX_INITIALIZER(mutexname) \
 	, .name = #mutexname, .file = __FILE__, .line = __LINE__
-# define rt_mutex_init(mutex)			__rt_mutex_init(mutex, __func__)
  extern void rt_mutex_debug_task_free(struct task_struct *tsk);
 #else
 # define __DEBUG_RT_MUTEX_INITIALIZER(mutexname)
-# define rt_mutex_init(mutex)			__rt_mutex_init(mutex, NULL)
 # define rt_mutex_debug_task_free(t)			do { } while (0)
 #endif
 
-#define __RT_MUTEX_INITIALIZER(mutexname) \
-	{ .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \
+#define __RT_MUTEX_INITIALIZER_PLAIN(mutexname) \
+	 .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \
 	, .waiters = RB_ROOT \
 	, .owner = NULL \
-	__DEBUG_RT_MUTEX_INITIALIZER(mutexname)}
+	__DEBUG_RT_MUTEX_INITIALIZER(mutexname)
+
+#define __RT_MUTEX_INITIALIZER(mutexname) \
+	{ __RT_MUTEX_INITIALIZER_PLAIN(mutexname) }
+
+#define __RT_MUTEX_INITIALIZER_SAVE_STATE(mutexname) \
+	{ __RT_MUTEX_INITIALIZER_PLAIN(mutexname)    \
+	, .save_state = 1 }
 
 #define DEFINE_RT_MUTEX(mutexname) \
 	struct rt_mutex mutexname = __RT_MUTEX_INITIALIZER(mutexname)
@@ -91,6 +106,7 @@
 
 extern void rt_mutex_lock(struct rt_mutex *lock);
 extern int rt_mutex_lock_interruptible(struct rt_mutex *lock);
+extern int rt_mutex_lock_killable(struct rt_mutex *lock);
 extern int rt_mutex_timed_lock(struct rt_mutex *lock,
 			       struct hrtimer_sleeper *timeout);
 
diff -Nur linux-3.18.12.orig/include/linux/rwlock_rt.h linux-3.18.12/include/linux/rwlock_rt.h
--- linux-3.18.12.orig/include/linux/rwlock_rt.h	1969-12-31 18:00:00.000000000 -0600
+++ linux-3.18.12/include/linux/rwlock_rt.h	2015-04-26 13:32:22.423684003 -0500
@@ -0,0 +1,99 @@
+#ifndef __LINUX_RWLOCK_RT_H
+#define __LINUX_RWLOCK_RT_H
+
+#ifndef __LINUX_SPINLOCK_H
+#error Do not include directly. Use spinlock.h
+#endif
+
+#define rwlock_init(rwl)				\
+do {							\
+	static struct lock_class_key __key;		\
+							\
+	rt_mutex_init(&(rwl)->lock);			\
+	__rt_rwlock_init(rwl, #rwl, &__key);		\
+} while (0)
+
+extern void __lockfunc rt_write_lock(rwlock_t *rwlock);
+extern void __lockfunc rt_read_lock(rwlock_t *rwlock);
+extern int __lockfunc rt_write_trylock(rwlock_t *rwlock);
+extern int __lockfunc rt_write_trylock_irqsave(rwlock_t *trylock, unsigned long *flags);
+extern int __lockfunc rt_read_trylock(rwlock_t *rwlock);
+extern void __lockfunc rt_write_unlock(rwlock_t *rwlock);
+extern void __lockfunc rt_read_unlock(rwlock_t *rwlock);
+extern unsigned long __lockfunc rt_write_lock_irqsave(rwlock_t *rwlock);
+extern unsigned long __lockfunc rt_read_lock_irqsave(rwlock_t *rwlock);
+extern void __rt_rwlock_init(rwlock_t *rwlock, char *name, struct lock_class_key *key);
+
+#define read_trylock(lock)	__cond_lock(lock, rt_read_trylock(lock))
+#define write_trylock(lock)	__cond_lock(lock, rt_write_trylock(lock))
+
+#define write_trylock_irqsave(lock, flags)	\
+	__cond_lock(lock, rt_write_trylock_irqsave(lock, &flags))
+
+#define read_lock_irqsave(lock, flags)			\
+	do {						\
+		typecheck(unsigned long, flags);	\
+		flags = rt_read_lock_irqsave(lock);	\
+	} while (0)
+
+#define write_lock_irqsave(lock, flags)			\
+	do {						\
+		typecheck(unsigned long, flags);	\
+		flags = rt_write_lock_irqsave(lock);	\
+	} while (0)
+
+#define read_lock(lock)		rt_read_lock(lock)
+
+#define read_lock_bh(lock)				\
+	do {						\
+		local_bh_disable();			\
+		rt_read_lock(lock);			\
+	} while (0)
+
+#define read_lock_irq(lock)	read_lock(lock)
+
+#define write_lock(lock)	rt_write_lock(lock)
+
+#define write_lock_bh(lock)				\
+	do {						\
+		local_bh_disable();			\
+		rt_write_lock(lock);			\
+	} while (0)
+
+#define write_lock_irq(lock)	write_lock(lock)
+
+#define read_unlock(lock)	rt_read_unlock(lock)
+
+#define read_unlock_bh(lock)				\
+	do {						\
+		rt_read_unlock(lock);			\
+		local_bh_enable();			\
+	} while (0)
+
+#define read_unlock_irq(lock)	read_unlock(lock)
+
+#define write_unlock(lock)	rt_write_unlock(lock)
+
+#define write_unlock_bh(lock)				\
+	do {						\
+		rt_write_unlock(lock);			\
+		local_bh_enable();			\
+	} while (0)
+
+#define write_unlock_irq(lock)	write_unlock(lock)
+
+#define read_unlock_irqrestore(lock, flags)		\
+	do {						\
+		typecheck(unsigned long, flags);	\
+		(void) flags;				\
+		rt_read_unlock(lock);			\
+	} while (0)
+
+#define write_unlock_irqrestore(lock, flags) \
+	do {						\
+		typecheck(unsigned long, flags);	\
+		(void) flags;				\
+		rt_write_unlock(lock);			\
+	} while (0)
+
+#endif
diff -Nur linux-3.18.12.orig/include/linux/rwlock_types.h linux-3.18.12/include/linux/rwlock_types.h
--- linux-3.18.12.orig/include/linux/rwlock_types.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/rwlock_types.h	2015-04-26 13:32:22.423684003 -0500
@@ -1,6 +1,10 @@
 #ifndef __LINUX_RWLOCK_TYPES_H
 #define __LINUX_RWLOCK_TYPES_H
 
+#if !defined(__LINUX_SPINLOCK_TYPES_H)
+# error "Do not include directly, include spinlock_types.h"
+#endif
+
 /*
  * include/linux/rwlock_types.h - generic rwlock type definitions
  *				  and initializers
@@ -43,6 +47,7 @@
 				RW_DEP_MAP_INIT(lockname) }
 #endif
 
-#define DEFINE_RWLOCK(x)	rwlock_t x = __RW_LOCK_UNLOCKED(x)
+#define DEFINE_RWLOCK(name) \
+	rwlock_t name __cacheline_aligned_in_smp = __RW_LOCK_UNLOCKED(name)
 
 #endif /* __LINUX_RWLOCK_TYPES_H */
diff -Nur linux-3.18.12.orig/include/linux/rwlock_types_rt.h linux-3.18.12/include/linux/rwlock_types_rt.h
--- linux-3.18.12.orig/include/linux/rwlock_types_rt.h	1969-12-31 18:00:00.000000000 -0600
+++ linux-3.18.12/include/linux/rwlock_types_rt.h	2015-04-26 13:32:22.423684003 -0500
@@ -0,0 +1,33 @@
+#ifndef __LINUX_RWLOCK_TYPES_RT_H
+#define __LINUX_RWLOCK_TYPES_RT_H
+
+#ifndef __LINUX_SPINLOCK_TYPES_H
+#error "Do not include directly. Include spinlock_types.h instead"
+#endif
+
+/*
+ * rwlocks - rtmutex which allows single reader recursion
+ */
+typedef struct {
+	struct rt_mutex		lock;
+	int			read_depth;
+	unsigned int		break_lock;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	struct lockdep_map	dep_map;
+#endif
+} rwlock_t;
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define RW_DEP_MAP_INIT(lockname)	.dep_map = { .name = #lockname }
+#else
+# define RW_DEP_MAP_INIT(lockname)
+#endif
+
+#define __RW_LOCK_UNLOCKED(name) \
+	{ .lock = __RT_MUTEX_INITIALIZER_SAVE_STATE(name.lock),	\
+	  RW_DEP_MAP_INIT(name) }
+
+#define DEFINE_RWLOCK(name) \
+	rwlock_t name __cacheline_aligned_in_smp = __RW_LOCK_UNLOCKED(name)
+
+#endif
diff -Nur linux-3.18.12.orig/include/linux/rwsem.h linux-3.18.12/include/linux/rwsem.h
--- linux-3.18.12.orig/include/linux/rwsem.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/rwsem.h	2015-04-26 13:32:22.423684003 -0500
@@ -18,6 +18,10 @@
 #include <linux/osq_lock.h>
 #endif
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+#include <linux/rwsem_rt.h>
+#else /* PREEMPT_RT_FULL */
+
 struct rw_semaphore;
 
 #ifdef CONFIG_RWSEM_GENERIC_SPINLOCK
@@ -177,4 +181,6 @@
 # define up_read_non_owner(sem)			up_read(sem)
 #endif
 
+#endif /* !PREEMPT_RT_FULL */
+
 #endif /* _LINUX_RWSEM_H */
diff -Nur linux-3.18.12.orig/include/linux/rwsem_rt.h linux-3.18.12/include/linux/rwsem_rt.h
--- linux-3.18.12.orig/include/linux/rwsem_rt.h	1969-12-31 18:00:00.000000000 -0600
+++ linux-3.18.12/include/linux/rwsem_rt.h	2015-04-26 13:32:22.423684003 -0500
@@ -0,0 +1,134 @@
+#ifndef _LINUX_RWSEM_RT_H
+#define _LINUX_RWSEM_RT_H
+
+#ifndef _LINUX_RWSEM_H
+#error "Include rwsem.h"
+#endif
+
+/*
+ * RW-semaphores are a spinlock plus a reader-depth count.
+ *
+ * Note that the semantics are different from the usual
+ * Linux rw-sems, in PREEMPT_RT mode we do not allow
+ * multiple readers to hold the lock at once, we only allow
+ * a read-lock owner to read-lock recursively. This is
+ * better for latency, makes the implementation inherently
+ * fair and makes it simpler as well.
+ */
+
+#include <linux/rtmutex.h>
+
+struct rw_semaphore {
+	struct rt_mutex		lock;
+	int			read_depth;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	struct lockdep_map	dep_map;
+#endif
+};
+
+#define __RWSEM_INITIALIZER(name) \
+	{ .lock = __RT_MUTEX_INITIALIZER(name.lock), \
+	  RW_DEP_MAP_INIT(name) }
+
+#define DECLARE_RWSEM(lockname) \
+	struct rw_semaphore lockname = __RWSEM_INITIALIZER(lockname)
+
+extern void  __rt_rwsem_init(struct rw_semaphore *rwsem, const char *name,
+				     struct lock_class_key *key);
+
+#define __rt_init_rwsem(sem, name, key)			\
+	do {						\
+		rt_mutex_init(&(sem)->lock);		\
+		__rt_rwsem_init((sem), (name), (key));\
+	} while (0)
+
+#define __init_rwsem(sem, name, key) __rt_init_rwsem(sem, name, key)
+
+# define rt_init_rwsem(sem)				\
+do {							\
+	static struct lock_class_key __key;		\
+							\
+	__rt_init_rwsem((sem), #sem, &__key);		\
+} while (0)
+
+extern void  rt_down_write(struct rw_semaphore *rwsem);
+extern void rt_down_read_nested(struct rw_semaphore *rwsem, int subclass);
+extern void rt_down_write_nested(struct rw_semaphore *rwsem, int subclass);
+extern void rt_down_write_nested_lock(struct rw_semaphore *rwsem,
+		struct lockdep_map *nest);
+extern void  rt_down_read(struct rw_semaphore *rwsem);
+extern int  rt_down_write_trylock(struct rw_semaphore *rwsem);
+extern int  rt_down_read_trylock(struct rw_semaphore *rwsem);
+extern void  rt_up_read(struct rw_semaphore *rwsem);
+extern void  rt_up_write(struct rw_semaphore *rwsem);
+extern void  rt_downgrade_write(struct rw_semaphore *rwsem);
+
+#define init_rwsem(sem)		rt_init_rwsem(sem)
+#define rwsem_is_locked(s)	rt_mutex_is_locked(&(s)->lock)
+
+static inline int rwsem_is_contended(struct rw_semaphore *sem)
+{
+	/* rt_mutex_has_waiters() */
+	return !RB_EMPTY_ROOT(&sem->lock.waiters);
+}
+
+static inline void down_read(struct rw_semaphore *sem)
+{
+	rt_down_read(sem);
+}
+
+static inline int down_read_trylock(struct rw_semaphore *sem)
+{
+	return rt_down_read_trylock(sem);
+}
+
+static inline void down_write(struct rw_semaphore *sem)
+{
+	rt_down_write(sem);
+}
+
+static inline int down_write_trylock(struct rw_semaphore *sem)
+{
+	return rt_down_write_trylock(sem);
+}
+
+static inline void up_read(struct rw_semaphore *sem)
+{
+	rt_up_read(sem);
+}
+
+static inline void up_write(struct rw_semaphore *sem)
+{
+	rt_up_write(sem);
+}
+
+static inline void downgrade_write(struct rw_semaphore *sem)
+{
+	rt_downgrade_write(sem);
+}
+
+static inline void down_read_nested(struct rw_semaphore *sem, int subclass)
+{
+	return rt_down_read_nested(sem, subclass);
+}
+
+static inline void down_write_nested(struct rw_semaphore *sem, int subclass)
+{
+	rt_down_write_nested(sem, subclass);
+}
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+static inline void down_write_nest_lock(struct rw_semaphore *sem,
+		struct rw_semaphore *nest_lock)
+{
+	rt_down_write_nested_lock(sem, &nest_lock->dep_map);
+}
+
+#else
+
+static inline void down_write_nest_lock(struct rw_semaphore *sem,
+		struct rw_semaphore *nest_lock)
+{
+	rt_down_write_nested_lock(sem, NULL);
+}
+#endif
+#endif
diff -Nur linux-3.18.12.orig/include/linux/sched.h linux-3.18.12/include/linux/sched.h
--- linux-3.18.12.orig/include/linux/sched.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/sched.h	2015-04-26 13:32:22.423684003 -0500
@@ -26,6 +26,7 @@
 #include <linux/nodemask.h>
 #include <linux/mm_types.h>
 #include <linux/preempt_mask.h>
+#include <asm/kmap_types.h>
 
 #include <asm/page.h>
 #include <asm/ptrace.h>
@@ -56,6 +57,7 @@
 #include <linux/cred.h>
 #include <linux/llist.h>
 #include <linux/uidgid.h>
+#include <linux/hardirq.h>
 #include <linux/gfp.h>
 #include <linux/magic.h>
 
@@ -235,10 +237,7 @@
 				 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
 				 __TASK_TRACED | EXIT_ZOMBIE | EXIT_DEAD)
 
-#define task_is_traced(task)	((task->state & __TASK_TRACED) != 0)
 #define task_is_stopped(task)	((task->state & __TASK_STOPPED) != 0)
-#define task_is_stopped_or_traced(task)	\
-			((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
 #define task_contributes_to_load(task)	\
 				((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
 				 (task->flags & PF_FROZEN) == 0)
@@ -1234,6 +1233,7 @@
 
 struct task_struct {
 	volatile long state;	/* -1 unrunnable, 0 runnable, >0 stopped */
+	volatile long saved_state;	/* saved state for "spinlock sleepers" */
 	void *stack;
 	atomic_t usage;
 	unsigned int flags;	/* per process flags, defined below */
@@ -1270,6 +1270,12 @@
 #endif
 
 	unsigned int policy;
+#ifdef CONFIG_PREEMPT_RT_FULL
+	int migrate_disable;
+# ifdef CONFIG_SCHED_DEBUG
+	int migrate_disable_atomic;
+# endif
+#endif
 	int nr_cpus_allowed;
 	cpumask_t cpus_allowed;
 
@@ -1371,7 +1377,8 @@
 	struct cputime prev_cputime;
 #endif
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
-	seqlock_t vtime_seqlock;
+	raw_spinlock_t vtime_lock;
+	seqcount_t vtime_seq;
 	unsigned long long vtime_snap;
 	enum {
 		VTIME_SLEEPING = 0,
@@ -1387,6 +1394,9 @@
 
 	struct task_cputime cputime_expires;
 	struct list_head cpu_timers[3];
+#ifdef CONFIG_PREEMPT_RT_BASE
+	struct task_struct *posix_timer_list;
+#endif
 
 /* process credentials */
 	const struct cred __rcu *real_cred; /* objective and real subjective task
@@ -1419,10 +1429,15 @@
 /* signal handlers */
 	struct signal_struct *signal;
 	struct sighand_struct *sighand;
+	struct sigqueue *sigqueue_cache;
 
 	sigset_t blocked, real_blocked;
 	sigset_t saved_sigmask;	/* restored if set_restore_sigmask() was used */
 	struct sigpending pending;
+#ifdef CONFIG_PREEMPT_RT_FULL
+	/* TODO: move me into ->restart_block ? */
+	struct siginfo forced_info;
+#endif
 
 	unsigned long sas_ss_sp;
 	size_t sas_ss_size;
@@ -1460,6 +1475,9 @@
 	/* mutex deadlock detection */
 	struct mutex_waiter *blocked_on;
 #endif
+#ifdef CONFIG_PREEMPT_RT_FULL
+	int pagefault_disabled;
+#endif
 #ifdef CONFIG_TRACE_IRQFLAGS
 	unsigned int irq_events;
 	unsigned long hardirq_enable_ip;
@@ -1644,6 +1662,12 @@
 	unsigned long trace;
 	/* bitmask and counter of trace recursion */
 	unsigned long trace_recursion;
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+	u64 preempt_timestamp_hist;
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+	long timer_offset;
+#endif
+#endif
 #endif /* CONFIG_TRACING */
 #ifdef CONFIG_MEMCG /* memcg uses this to do batch job */
 	unsigned int memcg_kmem_skip_account;
@@ -1661,11 +1685,19 @@
 	unsigned int	sequential_io;
 	unsigned int	sequential_io_avg;
 #endif
+#ifdef CONFIG_PREEMPT_RT_BASE
+	struct rcu_head put_rcu;
+	int softirq_nestcnt;
+	unsigned int softirqs_raised;
+#endif
+#ifdef CONFIG_PREEMPT_RT_FULL
+# if defined CONFIG_HIGHMEM || defined CONFIG_X86_32
+	int kmap_idx;
+	pte_t kmap_pte[KM_TYPE_NR];
+# endif
+#endif
 };
 
-/* Future-safe accessor for struct task_struct's cpus_allowed. */
-#define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
-
 #define TNF_MIGRATED	0x01
 #define TNF_NO_GROUP	0x02
 #define TNF_SHARED	0x04
@@ -1700,6 +1732,17 @@
 }
 #endif
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+static inline bool cur_pf_disabled(void) { return current->pagefault_disabled; }
+#else
+static inline bool cur_pf_disabled(void) { return false; }
+#endif
+
+static inline bool pagefault_disabled(void)
+{
+	return in_atomic() || cur_pf_disabled();
+}
+
 static inline struct pid *task_pid(struct task_struct *task)
 {
 	return task->pids[PIDTYPE_PID].pid;
@@ -1853,6 +1896,15 @@
 extern void free_task(struct task_struct *tsk);
 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
 
+#ifdef CONFIG_PREEMPT_RT_BASE
+extern void __put_task_struct_cb(struct rcu_head *rhp);
+
+static inline void put_task_struct(struct task_struct *t)
+{
+	if (atomic_dec_and_test(&t->usage))
+		call_rcu(&t->put_rcu, __put_task_struct_cb);
+}
+#else
 extern void __put_task_struct(struct task_struct *t);
 
 static inline void put_task_struct(struct task_struct *t)
@@ -1860,6 +1912,7 @@
 	if (atomic_dec_and_test(&t->usage))
 		__put_task_struct(t);
 }
+#endif
 
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
 extern void task_cputime(struct task_struct *t,
@@ -1898,6 +1951,7 @@
 /*
  * Per process flags
  */
+#define PF_IN_SOFTIRQ	0x00000001	/* Task is serving softirq */
 #define PF_EXITING	0x00000004	/* getting shut down */
 #define PF_EXITPIDONE	0x00000008	/* pi exit done on shut down */
 #define PF_VCPU		0x00000010	/* I'm a virtual CPU */
@@ -2058,6 +2112,10 @@
 
 extern int set_cpus_allowed_ptr(struct task_struct *p,
 				const struct cpumask *new_mask);
+int migrate_me(void);
+void tell_sched_cpu_down_begin(int cpu);
+void tell_sched_cpu_down_done(int cpu);
+
 #else
 static inline void do_set_cpus_allowed(struct task_struct *p,
 				      const struct cpumask *new_mask)
@@ -2070,6 +2128,9 @@
 		return -EINVAL;
 	return 0;
 }
+static inline int migrate_me(void) { return 0; }
+static inline void tell_sched_cpu_down_begin(int cpu) { }
+static inline void tell_sched_cpu_down_done(int cpu) { }
 #endif
 
 #ifdef CONFIG_NO_HZ_COMMON
@@ -2290,6 +2351,7 @@
 
 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
 extern int wake_up_process(struct task_struct *tsk);
+extern int wake_up_lock_sleeper(struct task_struct * tsk);
 extern void wake_up_new_task(struct task_struct *tsk);
 #ifdef CONFIG_SMP
  extern void kick_process(struct task_struct *tsk);
@@ -2406,12 +2468,24 @@
 
 /* mmdrop drops the mm and the page tables */
 extern void __mmdrop(struct mm_struct *);
+
 static inline void mmdrop(struct mm_struct * mm)
 {
 	if (unlikely(atomic_dec_and_test(&mm->mm_count)))
 		__mmdrop(mm);
 }
 
+#ifdef CONFIG_PREEMPT_RT_BASE
+extern void __mmdrop_delayed(struct rcu_head *rhp);
+static inline void mmdrop_delayed(struct mm_struct *mm)
+{
+	if (atomic_dec_and_test(&mm->mm_count))
+		call_rcu(&mm->delayed_drop, __mmdrop_delayed);
+}
+#else
+# define mmdrop_delayed(mm)	mmdrop(mm)
+#endif
+
 /* mmput gets rid of the mappings and all user-space */
 extern void mmput(struct mm_struct *);
 /* Grab a reference to a task's mm, if it is not already going away */
@@ -2719,6 +2793,43 @@
 	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
 }
 
+#ifdef CONFIG_PREEMPT_LAZY
+static inline void set_tsk_need_resched_lazy(struct task_struct *tsk)
+{
+	set_tsk_thread_flag(tsk,TIF_NEED_RESCHED_LAZY);
+}
+
+static inline void clear_tsk_need_resched_lazy(struct task_struct *tsk)
+{
+	clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED_LAZY);
+}
+
+static inline int test_tsk_need_resched_lazy(struct task_struct *tsk)
+{
+	return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED_LAZY));
+}
+
+static inline int need_resched_lazy(void)
+{
+	return test_thread_flag(TIF_NEED_RESCHED_LAZY);
+}
+
+static inline int need_resched_now(void)
+{
+	return test_thread_flag(TIF_NEED_RESCHED);
+}
+
+#else
+static inline void clear_tsk_need_resched_lazy(struct task_struct *tsk) { }
+static inline int need_resched_lazy(void) { return 0; }
+
+static inline int need_resched_now(void)
+{
+	return test_thread_flag(TIF_NEED_RESCHED);
+}
+
+#endif
+
 static inline int restart_syscall(void)
 {
 	set_tsk_thread_flag(current, TIF_SIGPENDING);
@@ -2750,6 +2861,51 @@
 	return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
 }
 
+static inline bool __task_is_stopped_or_traced(struct task_struct *task)
+{
+	if (task->state & (__TASK_STOPPED | __TASK_TRACED))
+		return true;
+#ifdef CONFIG_PREEMPT_RT_FULL
+	if (task->saved_state & (__TASK_STOPPED | __TASK_TRACED))
+		return true;
+#endif
+	return false;
+}
+
+static inline bool task_is_stopped_or_traced(struct task_struct *task)
+{
+	bool traced_stopped;
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&task->pi_lock, flags);
+	traced_stopped = __task_is_stopped_or_traced(task);
+	raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+#else
+	traced_stopped = __task_is_stopped_or_traced(task);
+#endif
+	return traced_stopped;
+}
+
+static inline bool task_is_traced(struct task_struct *task)
+{
+	bool traced = false;
+
+	if (task->state & __TASK_TRACED)
+		return true;
+#ifdef CONFIG_PREEMPT_RT_FULL
+	/* in case the task is sleeping on tasklist_lock */
+	raw_spin_lock_irq(&task->pi_lock);
+	if (task->state & __TASK_TRACED)
+		traced = true;
+	else if (task->saved_state & __TASK_TRACED)
+		traced = true;
+	raw_spin_unlock_irq(&task->pi_lock);
+#endif
+	return traced;
+}
+
 /*
  * cond_resched() and cond_resched_lock(): latency reduction via
  * explicit rescheduling in places that are safe. The return
@@ -2766,7 +2922,7 @@
 
 extern int __cond_resched_lock(spinlock_t *lock);
 
-#ifdef CONFIG_PREEMPT_COUNT
+#if defined(CONFIG_PREEMPT_COUNT) && !defined(CONFIG_PREEMPT_RT_FULL)
 #define PREEMPT_LOCK_OFFSET	PREEMPT_OFFSET
 #else
 #define PREEMPT_LOCK_OFFSET	0
@@ -2777,12 +2933,16 @@
 	__cond_resched_lock(lock);				\
 })
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 extern int __cond_resched_softirq(void);
 
 #define cond_resched_softirq() ({					\
 	__might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET);	\
 	__cond_resched_softirq();					\
 })
+#else
+# define cond_resched_softirq()		cond_resched()
+#endif
 
 static inline void cond_resched_rcu(void)
 {
@@ -2949,6 +3109,26 @@
 
 #endif /* CONFIG_SMP */
 
+static inline int __migrate_disabled(struct task_struct *p)
+{
+#ifdef CONFIG_PREEMPT_RT_FULL
+	return p->migrate_disable;
+#else
+	return 0;
+#endif
+}
+
+/* Future-safe accessor for struct task_struct's cpus_allowed. */
+static inline const struct cpumask *tsk_cpus_allowed(struct task_struct *p)
+{
+#ifdef CONFIG_PREEMPT_RT_FULL
+	if (p->migrate_disable)
+		return cpumask_of(task_cpu(p));
+#endif
+
+	return &p->cpus_allowed;
+}
+
 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
 
diff -Nur linux-3.18.12.orig/include/linux/seqlock.h linux-3.18.12/include/linux/seqlock.h
--- linux-3.18.12.orig/include/linux/seqlock.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/seqlock.h	2015-04-26 13:32:22.423684003 -0500
@@ -219,20 +219,30 @@
 	return __read_seqcount_retry(s, start);
 }
 
-
-
-static inline void raw_write_seqcount_begin(seqcount_t *s)
+static inline void __raw_write_seqcount_begin(seqcount_t *s)
 {
 	s->sequence++;
 	smp_wmb();
 }
 
-static inline void raw_write_seqcount_end(seqcount_t *s)
+static inline void raw_write_seqcount_begin(seqcount_t *s)
+{
+	preempt_disable_rt();
+	__raw_write_seqcount_begin(s);
+}
+
+static inline void __raw_write_seqcount_end(seqcount_t *s)
 {
 	smp_wmb();
 	s->sequence++;
 }
 
+static inline void raw_write_seqcount_end(seqcount_t *s)
+{
+	__raw_write_seqcount_end(s);
+	preempt_enable_rt();
+}
+
 /*
  * raw_write_seqcount_latch - redirect readers to even/odd copy
  * @s: pointer to seqcount_t
@@ -305,10 +315,32 @@
 /*
  * Read side functions for starting and finalizing a read side section.
  */
+#ifndef CONFIG_PREEMPT_RT_FULL
 static inline unsigned read_seqbegin(const seqlock_t *sl)
 {
 	return read_seqcount_begin(&sl->seqcount);
 }
+#else
+/*
+ * Starvation safe read side for RT
+ */
+static inline unsigned read_seqbegin(seqlock_t *sl)
+{
+	unsigned ret;
+
+repeat:
+	ret = ACCESS_ONCE(sl->seqcount.sequence);
+	if (unlikely(ret & 1)) {
+		/*
+		 * Take the lock and let the writer proceed (i.e. evtl
+		 * boost it), otherwise we could loop here forever.
+		 */
+		spin_unlock_wait(&sl->lock);
+		goto repeat;
+	}
+	return ret;
+}
+#endif
 
 static inline unsigned read_seqretry(const seqlock_t *sl, unsigned start)
 {
@@ -323,36 +355,36 @@
 static inline void write_seqlock(seqlock_t *sl)
 {
 	spin_lock(&sl->lock);
-	write_seqcount_begin(&sl->seqcount);
+	__raw_write_seqcount_begin(&sl->seqcount);
 }
 
 static inline void write_sequnlock(seqlock_t *sl)
 {
-	write_seqcount_end(&sl->seqcount);
+	__raw_write_seqcount_end(&sl->seqcount);
 	spin_unlock(&sl->lock);
 }
 
 static inline void write_seqlock_bh(seqlock_t *sl)
 {
 	spin_lock_bh(&sl->lock);
-	write_seqcount_begin(&sl->seqcount);
+	__raw_write_seqcount_begin(&sl->seqcount);
 }
 
 static inline void write_sequnlock_bh(seqlock_t *sl)
 {
-	write_seqcount_end(&sl->seqcount);
+	__raw_write_seqcount_end(&sl->seqcount);
 	spin_unlock_bh(&sl->lock);
 }
 
 static inline void write_seqlock_irq(seqlock_t *sl)
 {
 	spin_lock_irq(&sl->lock);
-	write_seqcount_begin(&sl->seqcount);
+	__raw_write_seqcount_begin(&sl->seqcount);
 }
 
 static inline void write_sequnlock_irq(seqlock_t *sl)
 {
-	write_seqcount_end(&sl->seqcount);
+	__raw_write_seqcount_end(&sl->seqcount);
 	spin_unlock_irq(&sl->lock);
 }
 
@@ -361,7 +393,7 @@
 	unsigned long flags;
 
 	spin_lock_irqsave(&sl->lock, flags);
-	write_seqcount_begin(&sl->seqcount);
+	__raw_write_seqcount_begin(&sl->seqcount);
 	return flags;
 }
 
@@ -371,7 +403,7 @@
 static inline void
 write_sequnlock_irqrestore(seqlock_t *sl, unsigned long flags)
 {
-	write_seqcount_end(&sl->seqcount);
+	__raw_write_seqcount_end(&sl->seqcount);
 	spin_unlock_irqrestore(&sl->lock, flags);
 }
 
diff -Nur linux-3.18.12.orig/include/linux/signal.h linux-3.18.12/include/linux/signal.h
--- linux-3.18.12.orig/include/linux/signal.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/signal.h	2015-04-26 13:32:22.423684003 -0500
@@ -218,6 +218,7 @@
 }
 
 extern void flush_sigqueue(struct sigpending *queue);
+extern void flush_task_sigqueue(struct task_struct *tsk);
 
 /* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */
 static inline int valid_signal(unsigned long sig)
diff -Nur linux-3.18.12.orig/include/linux/skbuff.h linux-3.18.12/include/linux/skbuff.h
--- linux-3.18.12.orig/include/linux/skbuff.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/skbuff.h	2015-04-26 13:32:22.423684003 -0500
@@ -172,6 +172,7 @@
 
 	__u32		qlen;
 	spinlock_t	lock;
+	raw_spinlock_t	raw_lock;
 };
 
 struct sk_buff;
@@ -1327,6 +1328,12 @@
 	__skb_queue_head_init(list);
 }
 
+static inline void skb_queue_head_init_raw(struct sk_buff_head *list)
+{
+	raw_spin_lock_init(&list->raw_lock);
+	__skb_queue_head_init(list);
+}
+
 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
 		struct lock_class_key *class)
 {
diff -Nur linux-3.18.12.orig/include/linux/smp.h linux-3.18.12/include/linux/smp.h
--- linux-3.18.12.orig/include/linux/smp.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/smp.h	2015-04-26 13:32:22.423684003 -0500
@@ -178,6 +178,9 @@
 #define get_cpu()		({ preempt_disable(); smp_processor_id(); })
 #define put_cpu()		preempt_enable()
 
+#define get_cpu_light()		({ migrate_disable(); smp_processor_id(); })
+#define put_cpu_light()		migrate_enable()
+
 /*
  * Callback to arch code if there's nosmp or maxcpus=0 on the
  * boot command line:
diff -Nur linux-3.18.12.orig/include/linux/spinlock_api_smp.h linux-3.18.12/include/linux/spinlock_api_smp.h
--- linux-3.18.12.orig/include/linux/spinlock_api_smp.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/spinlock_api_smp.h	2015-04-26 13:32:22.423684003 -0500
@@ -187,6 +187,8 @@
 	return 0;
 }
 
-#include <linux/rwlock_api_smp.h>
+#ifndef CONFIG_PREEMPT_RT_FULL
+# include <linux/rwlock_api_smp.h>
+#endif
 
 #endif /* __LINUX_SPINLOCK_API_SMP_H */
diff -Nur linux-3.18.12.orig/include/linux/spinlock.h linux-3.18.12/include/linux/spinlock.h
--- linux-3.18.12.orig/include/linux/spinlock.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/spinlock.h	2015-04-26 13:32:22.423684003 -0500
@@ -278,7 +278,11 @@
 #define raw_spin_can_lock(lock)	(!raw_spin_is_locked(lock))
 
 /* Include rwlock functions */
-#include <linux/rwlock.h>
+#ifdef CONFIG_PREEMPT_RT_FULL
+# include <linux/rwlock_rt.h>
+#else
+# include <linux/rwlock.h>
+#endif
 
 /*
  * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
@@ -289,6 +293,10 @@
 # include <linux/spinlock_api_up.h>
 #endif
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+# include <linux/spinlock_rt.h>
+#else /* PREEMPT_RT_FULL */
+
 /*
  * Map the spin_lock functions to the raw variants for PREEMPT_RT=n
  */
@@ -418,4 +426,6 @@
 #define atomic_dec_and_lock(atomic, lock) \
 		__cond_lock(lock, _atomic_dec_and_lock(atomic, lock))
 
+#endif /* !PREEMPT_RT_FULL */
+
 #endif /* __LINUX_SPINLOCK_H */
diff -Nur linux-3.18.12.orig/include/linux/spinlock_rt.h linux-3.18.12/include/linux/spinlock_rt.h
--- linux-3.18.12.orig/include/linux/spinlock_rt.h	1969-12-31 18:00:00.000000000 -0600
+++ linux-3.18.12/include/linux/spinlock_rt.h	2015-04-26 13:32:22.423684003 -0500
@@ -0,0 +1,167 @@
+#ifndef __LINUX_SPINLOCK_RT_H
+#define __LINUX_SPINLOCK_RT_H
+
+#ifndef __LINUX_SPINLOCK_H
+#error Do not include directly. Use spinlock.h
+#endif
+
+#include <linux/bug.h>
+
+extern void
+__rt_spin_lock_init(spinlock_t *lock, char *name, struct lock_class_key *key);
+
+#define spin_lock_init(slock)				\
+do {							\
+	static struct lock_class_key __key;		\
+							\
+	rt_mutex_init(&(slock)->lock);			\
+	__rt_spin_lock_init(slock, #slock, &__key);	\
+} while (0)
+
+extern void __lockfunc rt_spin_lock(spinlock_t *lock);
+extern unsigned long __lockfunc rt_spin_lock_trace_flags(spinlock_t *lock);
+extern void __lockfunc rt_spin_lock_nested(spinlock_t *lock, int subclass);
+extern void __lockfunc rt_spin_unlock(spinlock_t *lock);
+extern void __lockfunc rt_spin_unlock_after_trylock_in_irq(spinlock_t *lock);
+extern void __lockfunc rt_spin_unlock_wait(spinlock_t *lock);
+extern int __lockfunc rt_spin_trylock_irqsave(spinlock_t *lock, unsigned long *flags);
+extern int __lockfunc rt_spin_trylock_bh(spinlock_t *lock);
+extern int __lockfunc rt_spin_trylock(spinlock_t *lock);
+extern int atomic_dec_and_spin_lock(atomic_t *atomic, spinlock_t *lock);
+
+/*
+ * lockdep-less calls, for derived types like rwlock:
+ * (for trylock they can use rt_mutex_trylock() directly.
+ */
+extern void __lockfunc __rt_spin_lock(struct rt_mutex *lock);
+extern void __lockfunc __rt_spin_unlock(struct rt_mutex *lock);
+extern int __lockfunc __rt_spin_trylock(struct rt_mutex *lock);
+
+#define spin_lock(lock)				\
+	do {					\
+		migrate_disable();		\
+		rt_spin_lock(lock);		\
+	} while (0)
+
+#define spin_lock_bh(lock)			\
+	do {					\
+		local_bh_disable();		\
+		migrate_disable();		\
+		rt_spin_lock(lock);		\
+	} while (0)
+
+#define spin_lock_irq(lock)		spin_lock(lock)
+
+#define spin_do_trylock(lock)		__cond_lock(lock, rt_spin_trylock(lock))
+
+#define spin_trylock(lock)			\
+({						\
+	int __locked;				\
+	migrate_disable();			\
+	__locked = spin_do_trylock(lock);	\
+	if (!__locked)				\
+		migrate_enable();		\
+	__locked;				\
+})
+
+#ifdef CONFIG_LOCKDEP
+# define spin_lock_nested(lock, subclass)		\
+	do {						\
+		migrate_disable();			\
+		rt_spin_lock_nested(lock, subclass);	\
+	} while (0)
+
+# define spin_lock_irqsave_nested(lock, flags, subclass) \
+	do {						 \
+		typecheck(unsigned long, flags);	 \
+		flags = 0;				 \
+		migrate_disable();			 \
+		rt_spin_lock_nested(lock, subclass);	 \
+	} while (0)
+#else
+# define spin_lock_nested(lock, subclass)	spin_lock(lock)
+
+# define spin_lock_irqsave_nested(lock, flags, subclass) \
+	do {						 \
+		typecheck(unsigned long, flags);	 \
+		flags = 0;				 \
+		spin_lock(lock);			 \
+	} while (0)
+#endif
+
+#define spin_lock_irqsave(lock, flags)			 \
+	do {						 \
+		typecheck(unsigned long, flags);	 \
+		flags = 0;				 \
+		spin_lock(lock);			 \
+	} while (0)
+
+static inline unsigned long spin_lock_trace_flags(spinlock_t *lock)
+{
+	unsigned long flags = 0;
+#ifdef CONFIG_TRACE_IRQFLAGS
+	flags = rt_spin_lock_trace_flags(lock);
+#else
+	spin_lock(lock); /* lock_local */
+#endif
+	return flags;
+}
+
+/* FIXME: we need rt_spin_lock_nest_lock */
+#define spin_lock_nest_lock(lock, nest_lock) spin_lock_nested(lock, 0)
+
+#define spin_unlock(lock)				\
+	do {						\
+		rt_spin_unlock(lock);			\
+		migrate_enable();			\
+	} while (0)
+
+#define spin_unlock_bh(lock)				\
+	do {						\
+		rt_spin_unlock(lock);			\
+		migrate_enable();			\
+		local_bh_enable();			\
+	} while (0)
+
+#define spin_unlock_irq(lock)		spin_unlock(lock)
+
+#define spin_unlock_irqrestore(lock, flags)		\
+	do {						\
+		typecheck(unsigned long, flags);	\
+		(void) flags;				\
+		spin_unlock(lock);			\
+	} while (0)
+
+#define spin_trylock_bh(lock)	__cond_lock(lock, rt_spin_trylock_bh(lock))
+#define spin_trylock_irq(lock)	spin_trylock(lock)
+
+#define spin_trylock_irqsave(lock, flags)	\
+	rt_spin_trylock_irqsave(lock, &(flags))
+
+#define spin_unlock_wait(lock)		rt_spin_unlock_wait(lock)
+
+#ifdef CONFIG_GENERIC_LOCKBREAK
+# define spin_is_contended(lock)	((lock)->break_lock)
+#else
+# define spin_is_contended(lock)	(((void)(lock), 0))
+#endif
+
+static inline int spin_can_lock(spinlock_t *lock)
+{
+	return !rt_mutex_is_locked(&lock->lock);
+}
+
+static inline int spin_is_locked(spinlock_t *lock)
+{
+	return rt_mutex_is_locked(&lock->lock);
+}
+
+static inline void assert_spin_locked(spinlock_t *lock)
+{
+	BUG_ON(!spin_is_locked(lock));
+}
+
+#define atomic_dec_and_lock(atomic, lock) \
+	atomic_dec_and_spin_lock(atomic, lock)
+
+#endif
diff -Nur linux-3.18.12.orig/include/linux/spinlock_types.h linux-3.18.12/include/linux/spinlock_types.h
--- linux-3.18.12.orig/include/linux/spinlock_types.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/spinlock_types.h	2015-04-26 13:32:22.423684003 -0500
@@ -9,80 +9,15 @@
  * Released under the General Public License (GPL).
  */
 
-#if defined(CONFIG_SMP)
-# include <asm/spinlock_types.h>
-#else
-# include <linux/spinlock_types_up.h>
-#endif
-
-#include <linux/lockdep.h>
-
-typedef struct raw_spinlock {
-	arch_spinlock_t raw_lock;
-#ifdef CONFIG_GENERIC_LOCKBREAK
-	unsigned int break_lock;
-#endif
-#ifdef CONFIG_DEBUG_SPINLOCK
-	unsigned int magic, owner_cpu;
-	void *owner;
-#endif
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-	struct lockdep_map dep_map;
-#endif
-} raw_spinlock_t;
-
-#define SPINLOCK_MAGIC		0xdead4ead
-
-#define SPINLOCK_OWNER_INIT	((void *)-1L)
-
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-# define SPIN_DEP_MAP_INIT(lockname)	.dep_map = { .name = #lockname }
-#else
-# define SPIN_DEP_MAP_INIT(lockname)
-#endif
+#include <linux/spinlock_types_raw.h>
 
-#ifdef CONFIG_DEBUG_SPINLOCK
-# define SPIN_DEBUG_INIT(lockname)		\
-	.magic = SPINLOCK_MAGIC,		\
-	.owner_cpu = -1,			\
-	.owner = SPINLOCK_OWNER_INIT,
+#ifndef CONFIG_PREEMPT_RT_FULL
+# include <linux/spinlock_types_nort.h>
+# include <linux/rwlock_types.h>
 #else
-# define SPIN_DEBUG_INIT(lockname)
+# include <linux/rtmutex.h>
+# include <linux/spinlock_types_rt.h>
+# include <linux/rwlock_types_rt.h>
 #endif
 
-#define __RAW_SPIN_LOCK_INITIALIZER(lockname)	\
-	{					\
-	.raw_lock = __ARCH_SPIN_LOCK_UNLOCKED,	\
-	SPIN_DEBUG_INIT(lockname)		\
-	SPIN_DEP_MAP_INIT(lockname) }
-
-#define __RAW_SPIN_LOCK_UNLOCKED(lockname)	\
-	(raw_spinlock_t) __RAW_SPIN_LOCK_INITIALIZER(lockname)
-
-#define DEFINE_RAW_SPINLOCK(x)	raw_spinlock_t x = __RAW_SPIN_LOCK_UNLOCKED(x)
-
-typedef struct spinlock {
-	union {
-		struct raw_spinlock rlock;
-
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-# define LOCK_PADSIZE (offsetof(struct raw_spinlock, dep_map))
-		struct {
-			u8 __padding[LOCK_PADSIZE];
-			struct lockdep_map dep_map;
-		};
-#endif
-	};
-} spinlock_t;
-
-#define __SPIN_LOCK_INITIALIZER(lockname) \
-	{ { .rlock = __RAW_SPIN_LOCK_INITIALIZER(lockname) } }
-
-#define __SPIN_LOCK_UNLOCKED(lockname) \
-	(spinlock_t ) __SPIN_LOCK_INITIALIZER(lockname)
-
-#define DEFINE_SPINLOCK(x)	spinlock_t x = __SPIN_LOCK_UNLOCKED(x)
-
-#include <linux/rwlock_types.h>
-
 #endif /* __LINUX_SPINLOCK_TYPES_H */
diff -Nur linux-3.18.12.orig/include/linux/spinlock_types_nort.h linux-3.18.12/include/linux/spinlock_types_nort.h
--- linux-3.18.12.orig/include/linux/spinlock_types_nort.h	1969-12-31 18:00:00.000000000 -0600
+++ linux-3.18.12/include/linux/spinlock_types_nort.h	2015-04-26 13:32:22.423684003 -0500
@@ -0,0 +1,33 @@
+#ifndef __LINUX_SPINLOCK_TYPES_NORT_H
+#define __LINUX_SPINLOCK_TYPES_NORT_H
+
+#ifndef __LINUX_SPINLOCK_TYPES_H
+#error "Do not include directly. Include spinlock_types.h instead"
+#endif
+
+/*
+ * The non RT version maps spinlocks to raw_spinlocks
+ */
+typedef struct spinlock {
+	union {
+		struct raw_spinlock rlock;
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define LOCK_PADSIZE (offsetof(struct raw_spinlock, dep_map))
+		struct {
+			u8 __padding[LOCK_PADSIZE];
+			struct lockdep_map dep_map;
+		};
+#endif
+	};
+} spinlock_t;
+
+#define __SPIN_LOCK_INITIALIZER(lockname) \
+	{ { .rlock = __RAW_SPIN_LOCK_INITIALIZER(lockname) } }
+
+#define __SPIN_LOCK_UNLOCKED(lockname) \
+	(spinlock_t ) __SPIN_LOCK_INITIALIZER(lockname)
+
+#define DEFINE_SPINLOCK(x)	spinlock_t x = __SPIN_LOCK_UNLOCKED(x)
+
+#endif
diff -Nur linux-3.18.12.orig/include/linux/spinlock_types_raw.h linux-3.18.12/include/linux/spinlock_types_raw.h
--- linux-3.18.12.orig/include/linux/spinlock_types_raw.h	1969-12-31 18:00:00.000000000 -0600
+++ linux-3.18.12/include/linux/spinlock_types_raw.h	2015-04-26 13:32:22.423684003 -0500
@@ -0,0 +1,56 @@
+#ifndef __LINUX_SPINLOCK_TYPES_RAW_H
+#define __LINUX_SPINLOCK_TYPES_RAW_H
+
+#if defined(CONFIG_SMP)
+# include <asm/spinlock_types.h>
+#else
+# include <linux/spinlock_types_up.h>
+#endif
+
+#include <linux/lockdep.h>
+
+typedef struct raw_spinlock {
+	arch_spinlock_t raw_lock;
+#ifdef CONFIG_GENERIC_LOCKBREAK
+	unsigned int break_lock;
+#endif
+#ifdef CONFIG_DEBUG_SPINLOCK
+	unsigned int magic, owner_cpu;
+	void *owner;
+#endif
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	struct lockdep_map dep_map;
+#endif
+} raw_spinlock_t;
+
+#define SPINLOCK_MAGIC		0xdead4ead
+
+#define SPINLOCK_OWNER_INIT	((void *)-1L)
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define SPIN_DEP_MAP_INIT(lockname)	.dep_map = { .name = #lockname }
+#else
+# define SPIN_DEP_MAP_INIT(lockname)
+#endif
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+# define SPIN_DEBUG_INIT(lockname)		\
+	.magic = SPINLOCK_MAGIC,		\
+	.owner_cpu = -1,			\
+	.owner = SPINLOCK_OWNER_INIT,
+#else
+# define SPIN_DEBUG_INIT(lockname)
+#endif
+
+#define __RAW_SPIN_LOCK_INITIALIZER(lockname)	\
+	{					\
+	.raw_lock = __ARCH_SPIN_LOCK_UNLOCKED,	\
+	SPIN_DEBUG_INIT(lockname)		\
+	SPIN_DEP_MAP_INIT(lockname) }
+
+#define __RAW_SPIN_LOCK_UNLOCKED(lockname)	\
+	(raw_spinlock_t) __RAW_SPIN_LOCK_INITIALIZER(lockname)
+
+#define DEFINE_RAW_SPINLOCK(x)	raw_spinlock_t x = __RAW_SPIN_LOCK_UNLOCKED(x)
+
+#endif
diff -Nur linux-3.18.12.orig/include/linux/spinlock_types_rt.h linux-3.18.12/include/linux/spinlock_types_rt.h
--- linux-3.18.12.orig/include/linux/spinlock_types_rt.h	1969-12-31 18:00:00.000000000 -0600
+++ linux-3.18.12/include/linux/spinlock_types_rt.h	2015-04-26 13:32:22.423684003 -0500
@@ -0,0 +1,51 @@
+#ifndef __LINUX_SPINLOCK_TYPES_RT_H
+#define __LINUX_SPINLOCK_TYPES_RT_H
+
+#ifndef __LINUX_SPINLOCK_TYPES_H
+#error "Do not include directly. Include spinlock_types.h instead"
+#endif
+
+#include <linux/cache.h>
+
+/*
+ * PREEMPT_RT: spinlocks - an RT mutex plus lock-break field:
+ */
+typedef struct spinlock {
+	struct rt_mutex		lock;
+	unsigned int		break_lock;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	struct lockdep_map	dep_map;
+#endif
+} spinlock_t;
+
+#ifdef CONFIG_DEBUG_RT_MUTEXES
+# define __RT_SPIN_INITIALIZER(name) \
+	{ \
+	.wait_lock = __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \
+	.save_state = 1, \
+	.file = __FILE__, \
+	.line = __LINE__ , \
+	}
+#else
+# define __RT_SPIN_INITIALIZER(name) \
+	{								\
+	.wait_lock = __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock),		\
+	.save_state = 1, \
+	}
+#endif
+
+/*
+.wait_list = PLIST_HEAD_INIT_RAW((name).lock.wait_list, (name).lock.wait_lock)
+*/
+
+#define __SPIN_LOCK_UNLOCKED(name)			\
+	{ .lock = __RT_SPIN_INITIALIZER(name.lock),		\
+	  SPIN_DEP_MAP_INIT(name) }
+
+#define __DEFINE_SPINLOCK(name) \
+	spinlock_t name = __SPIN_LOCK_UNLOCKED(name)
+
+#define DEFINE_SPINLOCK(name) \
+	spinlock_t name __cacheline_aligned_in_smp = __SPIN_LOCK_UNLOCKED(name)
+
+#endif
diff -Nur linux-3.18.12.orig/include/linux/srcu.h linux-3.18.12/include/linux/srcu.h
--- linux-3.18.12.orig/include/linux/srcu.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/srcu.h	2015-04-26 13:32:22.427684003 -0500
@@ -84,10 +84,10 @@
 
 void process_srcu(struct work_struct *work);
 
-#define __SRCU_STRUCT_INIT(name)					\
+#define __SRCU_STRUCT_INIT(name, pcpu_name)				\
 	{								\
 		.completed = -300,					\
-		.per_cpu_ref = &name##_srcu_array,			\
+		.per_cpu_ref = &pcpu_name,				\
 		.queue_lock = __SPIN_LOCK_UNLOCKED(name.queue_lock),	\
 		.running = false,					\
 		.batch_queue = RCU_BATCH_INIT(name.batch_queue),	\
@@ -104,11 +104,12 @@
  */
 #define DEFINE_SRCU(name)						\
 	static DEFINE_PER_CPU(struct srcu_struct_array, name##_srcu_array);\
-	struct srcu_struct name = __SRCU_STRUCT_INIT(name);
+	struct srcu_struct name = __SRCU_STRUCT_INIT(name, name##_srcu_array);
 
 #define DEFINE_STATIC_SRCU(name)					\
 	static DEFINE_PER_CPU(struct srcu_struct_array, name##_srcu_array);\
-	static struct srcu_struct name = __SRCU_STRUCT_INIT(name);
+	static struct srcu_struct name = __SRCU_STRUCT_INIT(\
+		name, name##_srcu_array);
 
 /**
  * call_srcu() - Queue a callback for invocation after an SRCU grace period
diff -Nur linux-3.18.12.orig/include/linux/swap.h linux-3.18.12/include/linux/swap.h
--- linux-3.18.12.orig/include/linux/swap.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/swap.h	2015-04-26 13:32:22.427684003 -0500
@@ -11,6 +11,7 @@
 #include <linux/fs.h>
 #include <linux/atomic.h>
 #include <linux/page-flags.h>
+#include <linux/locallock.h>
 #include <asm/page.h>
 
 struct notifier_block;
@@ -260,7 +261,8 @@
 void *workingset_eviction(struct address_space *mapping, struct page *page);
 bool workingset_refault(void *shadow);
 void workingset_activation(struct page *page);
-extern struct list_lru workingset_shadow_nodes;
+extern struct list_lru __workingset_shadow_nodes;
+DECLARE_LOCAL_IRQ_LOCK(workingset_shadow_lock);
 
 static inline unsigned int workingset_node_pages(struct radix_tree_node *node)
 {
diff -Nur linux-3.18.12.orig/include/linux/sysctl.h linux-3.18.12/include/linux/sysctl.h
--- linux-3.18.12.orig/include/linux/sysctl.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/sysctl.h	2015-04-26 13:32:22.427684003 -0500
@@ -25,6 +25,7 @@
 #include <linux/rcupdate.h>
 #include <linux/wait.h>
 #include <linux/rbtree.h>
+#include <linux/atomic.h>
 #include <uapi/linux/sysctl.h>
 
 /* For the /proc/sys support */
diff -Nur linux-3.18.12.orig/include/linux/thread_info.h linux-3.18.12/include/linux/thread_info.h
--- linux-3.18.12.orig/include/linux/thread_info.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/thread_info.h	2015-04-26 13:32:22.427684003 -0500
@@ -102,7 +102,17 @@
 #define test_thread_flag(flag) \
 	test_ti_thread_flag(current_thread_info(), flag)
 
-#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
+#ifdef CONFIG_PREEMPT_LAZY
+#define tif_need_resched()	(test_thread_flag(TIF_NEED_RESCHED) || \
+				 test_thread_flag(TIF_NEED_RESCHED_LAZY))
+#define tif_need_resched_now()	(test_thread_flag(TIF_NEED_RESCHED))
+#define tif_need_resched_lazy()	test_thread_flag(TIF_NEED_RESCHED_LAZY))
+
+#else
+#define tif_need_resched()	test_thread_flag(TIF_NEED_RESCHED)
+#define tif_need_resched_now()	test_thread_flag(TIF_NEED_RESCHED)
+#define tif_need_resched_lazy()	0
+#endif
 
 #if defined TIF_RESTORE_SIGMASK && !defined HAVE_SET_RESTORE_SIGMASK
 /*
diff -Nur linux-3.18.12.orig/include/linux/timer.h linux-3.18.12/include/linux/timer.h
--- linux-3.18.12.orig/include/linux/timer.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/timer.h	2015-04-26 13:32:22.427684003 -0500
@@ -241,7 +241,7 @@
 
 extern int try_to_del_timer_sync(struct timer_list *timer);
 
-#ifdef CONFIG_SMP
+#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT_FULL)
   extern int del_timer_sync(struct timer_list *timer);
 #else
 # define del_timer_sync(t)		del_timer(t)
diff -Nur linux-3.18.12.orig/include/linux/uaccess.h linux-3.18.12/include/linux/uaccess.h
--- linux-3.18.12.orig/include/linux/uaccess.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/uaccess.h	2015-04-26 13:32:22.427684003 -0500
@@ -6,14 +6,9 @@
 
 /*
  * These routines enable/disable the pagefault handler in that
- * it will not take any locks and go straight to the fixup table.
- *
- * They have great resemblance to the preempt_disable/enable calls
- * and in fact they are identical; this is because currently there is
- * no other way to make the pagefault handlers do this. So we do
- * disable preemption but we don't necessarily care about that.
+ * it will not take any MM locks and go straight to the fixup table.
  */
-static inline void pagefault_disable(void)
+static inline void raw_pagefault_disable(void)
 {
 	preempt_count_inc();
 	/*
@@ -23,7 +18,7 @@
 	barrier();
 }
 
-static inline void pagefault_enable(void)
+static inline void raw_pagefault_enable(void)
 {
 #ifndef CONFIG_PREEMPT
 	/*
@@ -37,6 +32,21 @@
 #endif
 }
 
+#ifndef CONFIG_PREEMPT_RT_FULL
+static inline void pagefault_disable(void)
+{
+	raw_pagefault_disable();
+}
+
+static inline void pagefault_enable(void)
+{
+	raw_pagefault_enable();
+}
+#else
+extern void pagefault_disable(void);
+extern void pagefault_enable(void);
+#endif
+
 #ifndef ARCH_HAS_NOCACHE_UACCESS
 
 static inline unsigned long __copy_from_user_inatomic_nocache(void *to,
@@ -76,9 +86,9 @@
 		mm_segment_t old_fs = get_fs();		\
 							\
 		set_fs(KERNEL_DS);			\
-		pagefault_disable();			\
+		raw_pagefault_disable();		\
 		ret = __copy_from_user_inatomic(&(retval), (__force typeof(retval) __user *)(addr), sizeof(retval));		\
-		pagefault_enable();			\
+		raw_pagefault_enable();			\
 		set_fs(old_fs);				\
 		ret;					\
 	})
diff -Nur linux-3.18.12.orig/include/linux/uprobes.h linux-3.18.12/include/linux/uprobes.h
--- linux-3.18.12.orig/include/linux/uprobes.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/uprobes.h	2015-04-26 13:32:22.427684003 -0500
@@ -27,6 +27,7 @@
 #include <linux/errno.h>
 #include <linux/rbtree.h>
 #include <linux/types.h>
+#include <linux/wait.h>
 
 struct vm_area_struct;
 struct mm_struct;
diff -Nur linux-3.18.12.orig/include/linux/vmstat.h linux-3.18.12/include/linux/vmstat.h
--- linux-3.18.12.orig/include/linux/vmstat.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/vmstat.h	2015-04-26 13:32:22.427684003 -0500
@@ -33,7 +33,9 @@
  */
 static inline void __count_vm_event(enum vm_event_item item)
 {
+	preempt_disable_rt();
 	raw_cpu_inc(vm_event_states.event[item]);
+	preempt_enable_rt();
 }
 
 static inline void count_vm_event(enum vm_event_item item)
@@ -43,7 +45,9 @@
 
 static inline void __count_vm_events(enum vm_event_item item, long delta)
 {
+	preempt_disable_rt();
 	raw_cpu_add(vm_event_states.event[item], delta);
+	preempt_enable_rt();
 }
 
 static inline void count_vm_events(enum vm_event_item item, long delta)
diff -Nur linux-3.18.12.orig/include/linux/wait.h linux-3.18.12/include/linux/wait.h
--- linux-3.18.12.orig/include/linux/wait.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/linux/wait.h	2015-04-26 13:32:22.427684003 -0500
@@ -8,6 +8,7 @@
 #include <linux/spinlock.h>
 #include <asm/current.h>
 #include <uapi/linux/wait.h>
+#include <linux/atomic.h>
 
 typedef struct __wait_queue wait_queue_t;
 typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int flags, void *key);
diff -Nur linux-3.18.12.orig/include/linux/wait-simple.h linux-3.18.12/include/linux/wait-simple.h
--- linux-3.18.12.orig/include/linux/wait-simple.h	1969-12-31 18:00:00.000000000 -0600
+++ linux-3.18.12/include/linux/wait-simple.h	2015-04-26 13:32:22.427684003 -0500
@@ -0,0 +1,207 @@
+#ifndef _LINUX_WAIT_SIMPLE_H
+#define _LINUX_WAIT_SIMPLE_H
+
+#include <linux/spinlock.h>
+#include <linux/list.h>
+
+#include <asm/current.h>
+
+struct swaiter {
+	struct task_struct	*task;
+	struct list_head	node;
+};
+
+#define DEFINE_SWAITER(name)					\
+	struct swaiter name = {					\
+		.task	= current,				\
+		.node	= LIST_HEAD_INIT((name).node),		\
+	}
+
+struct swait_head {
+	raw_spinlock_t		lock;
+	struct list_head	list;
+};
+
+#define SWAIT_HEAD_INITIALIZER(name) {				\
+		.lock	= __RAW_SPIN_LOCK_UNLOCKED(name.lock),	\
+		.list	= LIST_HEAD_INIT((name).list),		\
+	}
+
+#define DEFINE_SWAIT_HEAD(name)					\
+	struct swait_head name = SWAIT_HEAD_INITIALIZER(name)
+
+extern void __init_swait_head(struct swait_head *h, struct lock_class_key *key);
+
+#define init_swait_head(swh)					\
+	do {							\
+		static struct lock_class_key __key;		\
+								\
+		__init_swait_head((swh), &__key);		\
+	} while (0)
+
+/*
+ * Waiter functions
+ */
+extern void swait_prepare_locked(struct swait_head *head, struct swaiter *w);
+extern void swait_prepare(struct swait_head *head, struct swaiter *w, int state);
+extern void swait_finish_locked(struct swait_head *head, struct swaiter *w);
+extern void swait_finish(struct swait_head *head, struct swaiter *w);
+
+/* Check whether a head has waiters enqueued */
+static inline bool swaitqueue_active(struct swait_head *h)
+{
+	/* Make sure the condition is visible before checking list_empty() */
+	smp_mb();
+	return !list_empty(&h->list);
+}
+
+/*
+ * Wakeup functions
+ */
+extern unsigned int __swait_wake(struct swait_head *head, unsigned int state, unsigned int num);
+extern unsigned int __swait_wake_locked(struct swait_head *head, unsigned int state, unsigned int num);
+
+#define swait_wake(head)			__swait_wake(head, TASK_NORMAL, 1)
+#define swait_wake_interruptible(head)		__swait_wake(head, TASK_INTERRUPTIBLE, 1)
+#define swait_wake_all(head)			__swait_wake(head, TASK_NORMAL, 0)
+#define swait_wake_all_interruptible(head)	__swait_wake(head, TASK_INTERRUPTIBLE, 0)
+
+/*
+ * Event API
+ */
+#define __swait_event(wq, condition)					\
+do {									\
+	DEFINE_SWAITER(__wait);						\
+									\
+	for (;;) {							\
+		swait_prepare(&wq, &__wait, TASK_UNINTERRUPTIBLE);	\
+		if (condition)						\
+			break;						\
+		schedule();						\
+	}								\
+	swait_finish(&wq, &__wait);					\
+} while (0)
+
+/**
+ * swait_event - sleep until a condition gets true
+ * @wq: the waitqueue to wait on
+ * @condition: a C expression for the event to wait for
+ *
+ * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
+ * @condition evaluates to true. The @condition is checked each time
+ * the waitqueue @wq is woken up.
+ *
+ * wake_up() has to be called after changing any variable that could
+ * change the result of the wait condition.
+ */
+#define swait_event(wq, condition)					\
+do {									\
+	if (condition)							\
+		break;							\
+	__swait_event(wq, condition);					\
+} while (0)
+
+#define __swait_event_interruptible(wq, condition, ret)			\
+do {									\
+	DEFINE_SWAITER(__wait);						\
+									\
+	for (;;) {							\
+		swait_prepare(&wq, &__wait, TASK_INTERRUPTIBLE);	\
+		if (condition)						\
+			break;						\
+		if (signal_pending(current)) {				\
+			ret = -ERESTARTSYS;				\
+			break;						\
+		}							\
+		schedule();						\
+	}								\
+	swait_finish(&wq, &__wait);					\
+} while (0)
+
+#define __swait_event_interruptible_timeout(wq, condition, ret)		\
+do {									\
+	DEFINE_SWAITER(__wait);						\
+									\
+	for (;;) {							\
+		swait_prepare(&wq, &__wait, TASK_INTERRUPTIBLE);	\
+		if (condition)						\
+			break;						\
+		if (signal_pending(current)) {				\
+			ret = -ERESTARTSYS;				\
+			break;						\
+		}							\
+		ret = schedule_timeout(ret);				\
+		if (!ret)						\
+			break;						\
+	}								\
+	swait_finish(&wq, &__wait);					\
+} while (0)
+
+/**
+ * swait_event_interruptible - sleep until a condition gets true
+ * @wq: the waitqueue to wait on
+ * @condition: a C expression for the event to wait for
+ *
+ * The process is put to sleep (TASK_INTERRUPTIBLE) until the
+ * @condition evaluates to true. The @condition is checked each time
+ * the waitqueue @wq is woken up.
+ *
+ * wake_up() has to be called after changing any variable that could
+ * change the result of the wait condition.
+ */
+#define swait_event_interruptible(wq, condition)			\
+({									\
+	int __ret = 0;							\
+	if (!(condition))						\
+		__swait_event_interruptible(wq, condition, __ret);	\
+	__ret;								\
+})
+
+#define swait_event_interruptible_timeout(wq, condition, timeout)	\
+({									\
+	int __ret = timeout;						\
+	if (!(condition))						\
+		__swait_event_interruptible_timeout(wq, condition, __ret);	\
+	__ret;								\
+})
+
+#define __swait_event_timeout(wq, condition, ret)			\
+do {									\
+	DEFINE_SWAITER(__wait);						\
+									\
+	for (;;) {							\
+		swait_prepare(&wq, &__wait, TASK_UNINTERRUPTIBLE);	\
+		if (condition)						\
+			break;						\
+		ret = schedule_timeout(ret);				\
+		if (!ret)						\
+			break;						\
+	}								\
+	swait_finish(&wq, &__wait);					\
+} while (0)
+
+/**
+ * swait_event_timeout - sleep until a condition gets true or a timeout elapses
+ * @wq: the waitqueue to wait on
+ * @condition: a C expression for the event to wait for
+ * @timeout: timeout, in jiffies
+ *
+ * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
+ * @condition evaluates to true. The @condition is checked each time
+ * the waitqueue @wq is woken up.
+ *
+ * wake_up() has to be called after changing any variable that could
+ * change the result of the wait condition.
+ *
+ * The function returns 0 if the @timeout elapsed, and the remaining
+ * jiffies if the condition evaluated to true before the timeout elapsed.
+ */
+#define swait_event_timeout(wq, condition, timeout)			\
+({									\
+	long __ret = timeout;						\
+	if (!(condition))						\
+		__swait_event_timeout(wq, condition, __ret);		\
+	__ret;								\
+})
+
+#endif
diff -Nur linux-3.18.12.orig/include/linux/work-simple.h linux-3.18.12/include/linux/work-simple.h
--- linux-3.18.12.orig/include/linux/work-simple.h	1969-12-31 18:00:00.000000000 -0600
+++ linux-3.18.12/include/linux/work-simple.h	2015-04-26 13:32:22.427684003 -0500
@@ -0,0 +1,24 @@
+#ifndef _LINUX_SWORK_H
+#define _LINUX_SWORK_H
+
+#include <linux/list.h>
+
+struct swork_event {
+	struct list_head item;
+	unsigned long flags;
+	void (*func)(struct swork_event *);
+};
+
+static inline void INIT_SWORK(struct swork_event *event,
+			      void (*func)(struct swork_event *))
+{
+	event->flags = 0;
+	event->func = func;
+}
+
+bool swork_queue(struct swork_event *sev);
+
+int swork_get(void);
+void swork_put(void);
+
+#endif /* _LINUX_SWORK_H */
diff -Nur linux-3.18.12.orig/include/net/dst.h linux-3.18.12/include/net/dst.h
--- linux-3.18.12.orig/include/net/dst.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/net/dst.h	2015-04-26 13:32:22.427684003 -0500
@@ -403,7 +403,7 @@
 static inline int dst_neigh_output(struct dst_entry *dst, struct neighbour *n,
 				   struct sk_buff *skb)
 {
-	const struct hh_cache *hh;
+	struct hh_cache *hh;
 
 	if (dst->pending_confirm) {
 		unsigned long now = jiffies;
diff -Nur linux-3.18.12.orig/include/net/neighbour.h linux-3.18.12/include/net/neighbour.h
--- linux-3.18.12.orig/include/net/neighbour.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/net/neighbour.h	2015-04-26 13:32:22.427684003 -0500
@@ -387,7 +387,7 @@
 }
 #endif
 
-static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb)
+static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb)
 {
 	unsigned int seq;
 	int hh_len;
@@ -442,7 +442,7 @@
 
 #define NEIGH_CB(skb)	((struct neighbour_cb *)(skb)->cb)
 
-static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n,
+static inline void neigh_ha_snapshot(char *dst, struct neighbour *n,
 				     const struct net_device *dev)
 {
 	unsigned int seq;
diff -Nur linux-3.18.12.orig/include/net/netns/ipv4.h linux-3.18.12/include/net/netns/ipv4.h
--- linux-3.18.12.orig/include/net/netns/ipv4.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/include/net/netns/ipv4.h	2015-04-26 13:32:22.427684003 -0500
@@ -67,6 +67,7 @@
 
 	int sysctl_icmp_echo_ignore_all;
 	int sysctl_icmp_echo_ignore_broadcasts;
+	int sysctl_icmp_echo_sysrq;
 	int sysctl_icmp_ignore_bogus_error_responses;
 	int sysctl_icmp_ratelimit;
 	int sysctl_icmp_ratemask;
diff -Nur linux-3.18.12.orig/include/trace/events/hist.h linux-3.18.12/include/trace/events/hist.h
--- linux-3.18.12.orig/include/trace/events/hist.h	1969-12-31 18:00:00.000000000 -0600
+++ linux-3.18.12/include/trace/events/hist.h	2015-04-26 13:32:22.427684003 -0500
@@ -0,0 +1,72 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM hist
+
+#if !defined(_TRACE_HIST_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_HIST_H
+
+#include "latency_hist.h"
+#include <linux/tracepoint.h>
+
+#if !defined(CONFIG_PREEMPT_OFF_HIST) && !defined(CONFIG_INTERRUPT_OFF_HIST)
+#define trace_preemptirqsoff_hist(a, b)
+#else
+TRACE_EVENT(preemptirqsoff_hist,
+
+	TP_PROTO(int reason, int starthist),
+
+	TP_ARGS(reason, starthist),
+
+	TP_STRUCT__entry(
+		__field(int,	reason)
+		__field(int,	starthist)
+	),
+
+	TP_fast_assign(
+		__entry->reason		= reason;
+		__entry->starthist	= starthist;
+	),
+
+	TP_printk("reason=%s starthist=%s", getaction(__entry->reason),
+		  __entry->starthist ? "start" : "stop")
+);
+#endif
+
+#ifndef CONFIG_MISSED_TIMER_OFFSETS_HIST
+#define trace_hrtimer_interrupt(a, b, c, d)
+#else
+TRACE_EVENT(hrtimer_interrupt,
+
+	TP_PROTO(int cpu, long long offset, struct task_struct *curr,
+		struct task_struct *task),
+
+	TP_ARGS(cpu, offset, curr, task),
+
+	TP_STRUCT__entry(
+		__field(int,		cpu)
+		__field(long long,	offset)
+		__array(char,		ccomm,	TASK_COMM_LEN)
+		__field(int,		cprio)
+		__array(char,		tcomm,	TASK_COMM_LEN)
+		__field(int,		tprio)
+	),
+
+	TP_fast_assign(
+		__entry->cpu	= cpu;
+		__entry->offset	= offset;
+		memcpy(__entry->ccomm, curr->comm, TASK_COMM_LEN);
+		__entry->cprio  = curr->prio;
+		memcpy(__entry->tcomm, task != NULL ? task->comm : "<none>",
+			task != NULL ? TASK_COMM_LEN : 7);
+		__entry->tprio  = task != NULL ? task->prio : -1;
+	),
+
+	TP_printk("cpu=%d offset=%lld curr=%s[%d] thread=%s[%d]",
+		__entry->cpu, __entry->offset, __entry->ccomm,
+		__entry->cprio, __entry->tcomm, __entry->tprio)
+);
+#endif
+
+#endif /* _TRACE_HIST_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff -Nur linux-3.18.12.orig/include/trace/events/latency_hist.h linux-3.18.12/include/trace/events/latency_hist.h
--- linux-3.18.12.orig/include/trace/events/latency_hist.h	1969-12-31 18:00:00.000000000 -0600
+++ linux-3.18.12/include/trace/events/latency_hist.h	2015-04-26 13:32:22.427684003 -0500
@@ -0,0 +1,29 @@
+#ifndef _LATENCY_HIST_H
+#define _LATENCY_HIST_H
+
+enum hist_action {
+	IRQS_ON,
+	PREEMPT_ON,
+	TRACE_STOP,
+	IRQS_OFF,
+	PREEMPT_OFF,
+	TRACE_START,
+};
+
+static char *actions[] = {
+	"IRQS_ON",
+	"PREEMPT_ON",
+	"TRACE_STOP",
+	"IRQS_OFF",
+	"PREEMPT_OFF",
+	"TRACE_START",
+};
+
+static inline char *getaction(int action)
+{
+	if (action >= 0 && action <= sizeof(actions)/sizeof(actions[0]))
+		return actions[action];
+	return "unknown";
+}
+
+#endif /* _LATENCY_HIST_H */
diff -Nur linux-3.18.12.orig/init/Kconfig linux-3.18.12/init/Kconfig
--- linux-3.18.12.orig/init/Kconfig	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/init/Kconfig	2015-04-26 13:32:22.427684003 -0500
@@ -635,7 +635,7 @@
 
 config RCU_FAST_NO_HZ
 	bool "Accelerate last non-dyntick-idle CPU's grace periods"
-	depends on NO_HZ_COMMON && SMP
+	depends on NO_HZ_COMMON && SMP && !PREEMPT_RT_FULL
 	default n
 	help
 	  This option permits CPUs to enter dynticks-idle state even if
@@ -662,7 +662,7 @@
 config RCU_BOOST
 	bool "Enable RCU priority boosting"
 	depends on RT_MUTEXES && PREEMPT_RCU
-	default n
+	default y if PREEMPT_RT_FULL
 	help
 	  This option boosts the priority of preempted RCU readers that
 	  block the current preemptible RCU grace period for too long.
@@ -1106,6 +1106,7 @@
 config RT_GROUP_SCHED
 	bool "Group scheduling for SCHED_RR/FIFO"
 	depends on CGROUP_SCHED
+	depends on !PREEMPT_RT_FULL
 	default n
 	help
 	  This feature lets you explicitly allocate real CPU bandwidth
@@ -1677,6 +1678,7 @@
 
 config SLAB
 	bool "SLAB"
+	depends on !PREEMPT_RT_FULL
 	help
 	  The regular slab allocator that is established and known to work
 	  well in all environments. It organizes cache hot objects in
@@ -1695,6 +1697,7 @@
 config SLOB
 	depends on EXPERT
 	bool "SLOB (Simple Allocator)"
+	depends on !PREEMPT_RT_FULL
 	help
 	   SLOB replaces the stock allocator with a drastically simpler
 	   allocator. SLOB is generally more space efficient but
diff -Nur linux-3.18.12.orig/init/main.c linux-3.18.12/init/main.c
--- linux-3.18.12.orig/init/main.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/init/main.c	2015-04-26 13:32:22.427684003 -0500
@@ -533,6 +533,7 @@
 	setup_command_line(command_line);
 	setup_nr_cpu_ids();
 	setup_per_cpu_areas();
+	softirq_early_init();
 	smp_prepare_boot_cpu();	/* arch-specific boot-cpu hooks */
 
 	build_all_zonelists(NULL, NULL);
diff -Nur linux-3.18.12.orig/init/Makefile linux-3.18.12/init/Makefile
--- linux-3.18.12.orig/init/Makefile	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/init/Makefile	2015-04-26 13:32:22.427684003 -0500
@@ -33,4 +33,4 @@
 include/generated/compile.h: FORCE
 	@$($(quiet)chk_compile.h)
 	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkcompile_h $@ \
-	"$(UTS_MACHINE)" "$(CONFIG_SMP)" "$(CONFIG_PREEMPT)" "$(CC) $(KBUILD_CFLAGS)"
+	"$(UTS_MACHINE)" "$(CONFIG_SMP)" "$(CONFIG_PREEMPT)" "$(CONFIG_PREEMPT_RT_FULL)" "$(CC) $(KBUILD_CFLAGS)"
diff -Nur linux-3.18.12.orig/ipc/mqueue.c linux-3.18.12/ipc/mqueue.c
--- linux-3.18.12.orig/ipc/mqueue.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/ipc/mqueue.c	2015-04-26 13:32:22.427684003 -0500
@@ -923,12 +923,17 @@
 				  struct msg_msg *message,
 				  struct ext_wait_queue *receiver)
 {
+	/*
+	 * Keep them in one critical section for PREEMPT_RT:
+	 */
+	preempt_disable_rt();
 	receiver->msg = message;
 	list_del(&receiver->list);
 	receiver->state = STATE_PENDING;
 	wake_up_process(receiver->task);
 	smp_wmb();
 	receiver->state = STATE_READY;
+	preempt_enable_rt();
 }
 
 /* pipelined_receive() - if there is task waiting in sys_mq_timedsend()
@@ -942,13 +947,18 @@
 		wake_up_interruptible(&info->wait_q);
 		return;
 	}
-	if (msg_insert(sender->msg, info))
-		return;
-	list_del(&sender->list);
-	sender->state = STATE_PENDING;
-	wake_up_process(sender->task);
-	smp_wmb();
-	sender->state = STATE_READY;
+	/*
+	 * Keep them in one critical section for PREEMPT_RT:
+	 */
+	preempt_disable_rt();
+	if (!msg_insert(sender->msg, info)) {
+		list_del(&sender->list);
+		sender->state = STATE_PENDING;
+		wake_up_process(sender->task);
+		smp_wmb();
+		sender->state = STATE_READY;
+	}
+	preempt_enable_rt();
 }
 
 SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr,
diff -Nur linux-3.18.12.orig/ipc/msg.c linux-3.18.12/ipc/msg.c
--- linux-3.18.12.orig/ipc/msg.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/ipc/msg.c	2015-04-26 13:32:22.427684003 -0500
@@ -188,6 +188,12 @@
 	struct msg_receiver *msr, *t;
 
 	list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
+		/*
+		 * Make sure that the wakeup doesnt preempt
+		 * this CPU prematurely. (on PREEMPT_RT)
+		 */
+		preempt_disable_rt();
+
 		msr->r_msg = NULL; /* initialize expunge ordering */
 		wake_up_process(msr->r_tsk);
 		/*
@@ -198,6 +204,8 @@
 		 */
 		smp_mb();
 		msr->r_msg = ERR_PTR(res);
+
+		preempt_enable_rt();
 	}
 }
 
@@ -574,6 +582,11 @@
 		if (testmsg(msg, msr->r_msgtype, msr->r_mode) &&
 		    !security_msg_queue_msgrcv(msq, msg, msr->r_tsk,
 					       msr->r_msgtype, msr->r_mode)) {
+			/*
+			 * Make sure that the wakeup doesnt preempt
+			 * this CPU prematurely. (on PREEMPT_RT)
+			 */
+			preempt_disable_rt();
 
 			list_del(&msr->r_list);
 			if (msr->r_maxsize < msg->m_ts) {
@@ -595,12 +608,13 @@
 				 */
 				smp_mb();
 				msr->r_msg = msg;
+				preempt_enable_rt();
 
 				return 1;
 			}
+			preempt_enable_rt();
 		}
 	}
-
 	return 0;
 }
 
diff -Nur linux-3.18.12.orig/ipc/sem.c linux-3.18.12/ipc/sem.c
--- linux-3.18.12.orig/ipc/sem.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/ipc/sem.c	2015-04-26 13:32:22.431684003 -0500
@@ -673,6 +673,13 @@
 static void wake_up_sem_queue_prepare(struct list_head *pt,
 				struct sem_queue *q, int error)
 {
+#ifdef CONFIG_PREEMPT_RT_BASE
+	struct task_struct *p = q->sleeper;
+	get_task_struct(p);
+	q->status = error;
+	wake_up_process(p);
+	put_task_struct(p);
+#else
 	if (list_empty(pt)) {
 		/*
 		 * Hold preempt off so that we don't get preempted and have the
@@ -684,6 +691,7 @@
 	q->pid = error;
 
 	list_add_tail(&q->list, pt);
+#endif
 }
 
 /**
@@ -697,6 +705,7 @@
  */
 static void wake_up_sem_queue_do(struct list_head *pt)
 {
+#ifndef CONFIG_PREEMPT_RT_BASE
 	struct sem_queue *q, *t;
 	int did_something;
 
@@ -709,6 +718,7 @@
 	}
 	if (did_something)
 		preempt_enable();
+#endif
 }
 
 static void unlink_queue(struct sem_array *sma, struct sem_queue *q)
diff -Nur linux-3.18.12.orig/kernel/cgroup.c linux-3.18.12/kernel/cgroup.c
--- linux-3.18.12.orig/kernel/cgroup.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/cgroup.c	2015-04-26 13:32:22.431684003 -0500
@@ -4355,10 +4355,10 @@
 	queue_work(cgroup_destroy_wq, &css->destroy_work);
 }
 
-static void css_release_work_fn(struct work_struct *work)
+static void css_release_work_fn(struct swork_event *sev)
 {
 	struct cgroup_subsys_state *css =
-		container_of(work, struct cgroup_subsys_state, destroy_work);
+		container_of(sev, struct cgroup_subsys_state, destroy_swork);
 	struct cgroup_subsys *ss = css->ss;
 	struct cgroup *cgrp = css->cgroup;
 
@@ -4395,8 +4395,8 @@
 	struct cgroup_subsys_state *css =
 		container_of(ref, struct cgroup_subsys_state, refcnt);
 
-	INIT_WORK(&css->destroy_work, css_release_work_fn);
-	queue_work(cgroup_destroy_wq, &css->destroy_work);
+	INIT_SWORK(&css->destroy_swork, css_release_work_fn);
+	swork_queue(&css->destroy_swork);
 }
 
 static void init_and_link_css(struct cgroup_subsys_state *css,
@@ -4997,6 +4997,7 @@
 	 */
 	cgroup_destroy_wq = alloc_workqueue("cgroup_destroy", 0, 1);
 	BUG_ON(!cgroup_destroy_wq);
+	BUG_ON(swork_get());
 
 	/*
 	 * Used to destroy pidlists and separate to serve as flush domain.
diff -Nur linux-3.18.12.orig/kernel/cpu.c linux-3.18.12/kernel/cpu.c
--- linux-3.18.12.orig/kernel/cpu.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/cpu.c	2015-04-26 13:32:22.431684003 -0500
@@ -86,6 +86,290 @@
 #define cpuhp_lock_acquire()      lock_map_acquire(&cpu_hotplug.dep_map)
 #define cpuhp_lock_release()      lock_map_release(&cpu_hotplug.dep_map)
 
+/**
+ * hotplug_pcp	- per cpu hotplug descriptor
+ * @unplug:	set when pin_current_cpu() needs to sync tasks
+ * @sync_tsk:	the task that waits for tasks to finish pinned sections
+ * @refcount:	counter of tasks in pinned sections
+ * @grab_lock:	set when the tasks entering pinned sections should wait
+ * @synced:	notifier for @sync_tsk to tell cpu_down it's finished
+ * @mutex:	the mutex to make tasks wait (used when @grab_lock is true)
+ * @mutex_init:	zero if the mutex hasn't been initialized yet.
+ *
+ * Although @unplug and @sync_tsk may point to the same task, the @unplug
+ * is used as a flag and still exists after @sync_tsk has exited and
+ * @sync_tsk set to NULL.
+ */
+struct hotplug_pcp {
+	struct task_struct *unplug;
+	struct task_struct *sync_tsk;
+	int refcount;
+	int grab_lock;
+	struct completion synced;
+	struct completion unplug_wait;
+#ifdef CONFIG_PREEMPT_RT_FULL
+	/*
+	 * Note, on PREEMPT_RT, the hotplug lock must save the state of
+	 * the task, otherwise the mutex will cause the task to fail
+	 * to sleep when required. (Because it's called from migrate_disable())
+	 *
+	 * The spinlock_t on PREEMPT_RT is a mutex that saves the task's
+	 * state.
+	 */
+	spinlock_t lock;
+#else
+	struct mutex mutex;
+#endif
+	int mutex_init;
+};
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define hotplug_lock(hp) rt_spin_lock(&(hp)->lock)
+# define hotplug_unlock(hp) rt_spin_unlock(&(hp)->lock)
+#else
+# define hotplug_lock(hp) mutex_lock(&(hp)->mutex)
+# define hotplug_unlock(hp) mutex_unlock(&(hp)->mutex)
+#endif
+
+static DEFINE_PER_CPU(struct hotplug_pcp, hotplug_pcp);
+
+/**
+ * pin_current_cpu - Prevent the current cpu from being unplugged
+ *
+ * Lightweight version of get_online_cpus() to prevent cpu from being
+ * unplugged when code runs in a migration disabled region.
+ *
+ * Must be called with preemption disabled (preempt_count = 1)!
+ */
+void pin_current_cpu(void)
+{
+	struct hotplug_pcp *hp;
+	int force = 0;
+
+retry:
+	hp = &__get_cpu_var(hotplug_pcp);
+
+	if (!hp->unplug || hp->refcount || force || preempt_count() > 1 ||
+	    hp->unplug == current) {
+		hp->refcount++;
+		return;
+	}
+	if (hp->grab_lock) {
+		preempt_enable();
+		hotplug_lock(hp);
+		hotplug_unlock(hp);
+	} else {
+		preempt_enable();
+		/*
+		 * Try to push this task off of this CPU.
+		 */
+		if (!migrate_me()) {
+			preempt_disable();
+			hp = &__get_cpu_var(hotplug_pcp);
+			if (!hp->grab_lock) {
+				/*
+				 * Just let it continue it's already pinned
+				 * or about to sleep.
+				 */
+				force = 1;
+				goto retry;
+			}
+			preempt_enable();
+		}
+	}
+	preempt_disable();
+	goto retry;
+}
+
+/**
+ * unpin_current_cpu - Allow unplug of current cpu
+ *
+ * Must be called with preemption or interrupts disabled!
+ */
+void unpin_current_cpu(void)
+{
+	struct hotplug_pcp *hp = &__get_cpu_var(hotplug_pcp);
+
+	WARN_ON(hp->refcount <= 0);
+
+	/* This is safe. sync_unplug_thread is pinned to this cpu */
+	if (!--hp->refcount && hp->unplug && hp->unplug != current)
+		wake_up_process(hp->unplug);
+}
+
+static void wait_for_pinned_cpus(struct hotplug_pcp *hp)
+{
+	set_current_state(TASK_UNINTERRUPTIBLE);
+	while (hp->refcount) {
+		schedule_preempt_disabled();
+		set_current_state(TASK_UNINTERRUPTIBLE);
+	}
+}
+
+static int sync_unplug_thread(void *data)
+{
+	struct hotplug_pcp *hp = data;
+
+	wait_for_completion(&hp->unplug_wait);
+	preempt_disable();
+	hp->unplug = current;
+	wait_for_pinned_cpus(hp);
+
+	/*
+	 * This thread will synchronize the cpu_down() with threads
+	 * that have pinned the CPU. When the pinned CPU count reaches
+	 * zero, we inform the cpu_down code to continue to the next step.
+	 */
+	set_current_state(TASK_UNINTERRUPTIBLE);
+	preempt_enable();
+	complete(&hp->synced);
+
+	/*
+	 * If all succeeds, the next step will need tasks to wait till
+	 * the CPU is offline before continuing. To do this, the grab_lock
+	 * is set and tasks going into pin_current_cpu() will block on the
+	 * mutex. But we still need to wait for those that are already in
+	 * pinned CPU sections. If the cpu_down() failed, the kthread_should_stop()
+	 * will kick this thread out.
+	 */
+	while (!hp->grab_lock && !kthread_should_stop()) {
+		schedule();
+		set_current_state(TASK_UNINTERRUPTIBLE);
+	}
+
+	/* Make sure grab_lock is seen before we see a stale completion */
+	smp_mb();
+
+	/*
+	 * Now just before cpu_down() enters stop machine, we need to make
+	 * sure all tasks that are in pinned CPU sections are out, and new
+	 * tasks will now grab the lock, keeping them from entering pinned
+	 * CPU sections.
+	 */
+	if (!kthread_should_stop()) {
+		preempt_disable();
+		wait_for_pinned_cpus(hp);
+		preempt_enable();
+		complete(&hp->synced);
+	}
+
+	set_current_state(TASK_UNINTERRUPTIBLE);
+	while (!kthread_should_stop()) {
+		schedule();
+		set_current_state(TASK_UNINTERRUPTIBLE);
+	}
+	set_current_state(TASK_RUNNING);
+
+	/*
+	 * Force this thread off this CPU as it's going down and
+	 * we don't want any more work on this CPU.
+	 */
+	current->flags &= ~PF_NO_SETAFFINITY;
+	set_cpus_allowed_ptr(current, cpu_present_mask);
+	migrate_me();
+	return 0;
+}
+
+static void __cpu_unplug_sync(struct hotplug_pcp *hp)
+{
+	wake_up_process(hp->sync_tsk);
+	wait_for_completion(&hp->synced);
+}
+
+static void __cpu_unplug_wait(unsigned int cpu)
+{
+	struct hotplug_pcp *hp = &per_cpu(hotplug_pcp, cpu);
+
+	complete(&hp->unplug_wait);
+	wait_for_completion(&hp->synced);
+}
+
+/*
+ * Start the sync_unplug_thread on the target cpu and wait for it to
+ * complete.
+ */
+static int cpu_unplug_begin(unsigned int cpu)
+{
+	struct hotplug_pcp *hp = &per_cpu(hotplug_pcp, cpu);
+	int err;
+
+	/* Protected by cpu_hotplug.lock */
+	if (!hp->mutex_init) {
+#ifdef CONFIG_PREEMPT_RT_FULL
+		spin_lock_init(&hp->lock);
+#else
+		mutex_init(&hp->mutex);
+#endif
+		hp->mutex_init = 1;
+	}
+
+	/* Inform the scheduler to migrate tasks off this CPU */
+	tell_sched_cpu_down_begin(cpu);
+
+	init_completion(&hp->synced);
+	init_completion(&hp->unplug_wait);
+
+	hp->sync_tsk = kthread_create(sync_unplug_thread, hp, "sync_unplug/%d", cpu);
+	if (IS_ERR(hp->sync_tsk)) {
+		err = PTR_ERR(hp->sync_tsk);
+		hp->sync_tsk = NULL;
+		return err;
+	}
+	kthread_bind(hp->sync_tsk, cpu);
+
+	/*
+	 * Wait for tasks to get out of the pinned sections,
+	 * it's still OK if new tasks enter. Some CPU notifiers will
+	 * wait for tasks that are going to enter these sections and
+	 * we must not have them block.
+	 */
+	wake_up_process(hp->sync_tsk);
+	return 0;
+}
+
+static void cpu_unplug_sync(unsigned int cpu)
+{
+	struct hotplug_pcp *hp = &per_cpu(hotplug_pcp, cpu);
+
+	init_completion(&hp->synced);
+	/* The completion needs to be initialzied before setting grab_lock */
+	smp_wmb();
+
+	/* Grab the mutex before setting grab_lock */
+	hotplug_lock(hp);
+	hp->grab_lock = 1;
+
+	/*
+	 * The CPU notifiers have been completed.
+	 * Wait for tasks to get out of pinned CPU sections and have new
+	 * tasks block until the CPU is completely down.
+	 */
+	__cpu_unplug_sync(hp);
+
+	/* All done with the sync thread */
+	kthread_stop(hp->sync_tsk);
+	hp->sync_tsk = NULL;
+}
+
+static void cpu_unplug_done(unsigned int cpu)
+{
+	struct hotplug_pcp *hp = &per_cpu(hotplug_pcp, cpu);
+
+	hp->unplug = NULL;
+	/* Let all tasks know cpu unplug is finished before cleaning up */
+	smp_wmb();
+
+	if (hp->sync_tsk)
+		kthread_stop(hp->sync_tsk);
+
+	if (hp->grab_lock) {
+		hotplug_unlock(hp);
+		/* protected by cpu_hotplug.lock */
+		hp->grab_lock = 0;
+	}
+	tell_sched_cpu_down_done(cpu);
+}
+
 void get_online_cpus(void)
 {
 	might_sleep();
@@ -102,6 +386,7 @@
 {
 	if (cpu_hotplug.active_writer == current)
 		return true;
+
 	if (!mutex_trylock(&cpu_hotplug.lock))
 		return false;
 	cpuhp_lock_acquire_tryread();
@@ -349,13 +634,15 @@
 /* Requires cpu_add_remove_lock to be held */
 static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
 {
-	int err, nr_calls = 0;
+	int mycpu, err, nr_calls = 0;
 	void *hcpu = (void *)(long)cpu;
 	unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
 	struct take_cpu_down_param tcd_param = {
 		.mod = mod,
 		.hcpu = hcpu,
 	};
+	cpumask_var_t cpumask;
+	cpumask_var_t cpumask_org;
 
 	if (num_online_cpus() == 1)
 		return -EBUSY;
@@ -363,7 +650,34 @@
 	if (!cpu_online(cpu))
 		return -EINVAL;
 
+	/* Move the downtaker off the unplug cpu */
+	if (!alloc_cpumask_var(&cpumask, GFP_KERNEL))
+		return -ENOMEM;
+	if (!alloc_cpumask_var(&cpumask_org, GFP_KERNEL))  {
+		free_cpumask_var(cpumask);
+		return -ENOMEM;
+	}
+
+	cpumask_copy(cpumask_org, tsk_cpus_allowed(current));
+	cpumask_andnot(cpumask, cpu_online_mask, cpumask_of(cpu));
+	set_cpus_allowed_ptr(current, cpumask);
+	free_cpumask_var(cpumask);
+	migrate_disable();
+	mycpu = smp_processor_id();
+	if (mycpu == cpu) {
+		printk(KERN_ERR "Yuck! Still on unplug CPU\n!");
+		migrate_enable();
+		err = -EBUSY;
+		goto restore_cpus;
+	}
+	migrate_enable();
+
 	cpu_hotplug_begin();
+	err = cpu_unplug_begin(cpu);
+	if (err) {
+		printk("cpu_unplug_begin(%d) failed\n", cpu);
+		goto out_cancel;
+	}
 
 	err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls);
 	if (err) {
@@ -389,8 +703,12 @@
 #endif
 	synchronize_rcu();
 
+	__cpu_unplug_wait(cpu);
 	smpboot_park_threads(cpu);
 
+	/* Notifiers are done. Don't let any more tasks pin this CPU. */
+	cpu_unplug_sync(cpu);
+
 	/*
 	 * So now all preempt/rcu users must observe !cpu_active().
 	 */
@@ -423,9 +741,14 @@
 	check_for_tasks(cpu);
 
 out_release:
+	cpu_unplug_done(cpu);
+out_cancel:
 	cpu_hotplug_done();
 	if (!err)
 		cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu);
+restore_cpus:
+	set_cpus_allowed_ptr(current, cpumask_org);
+	free_cpumask_var(cpumask_org);
 	return err;
 }
 
diff -Nur linux-3.18.12.orig/kernel/debug/kdb/kdb_io.c linux-3.18.12/kernel/debug/kdb/kdb_io.c
--- linux-3.18.12.orig/kernel/debug/kdb/kdb_io.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/debug/kdb/kdb_io.c	2015-04-26 13:32:22.431684003 -0500
@@ -554,7 +554,6 @@
 	int linecount;
 	int colcount;
 	int logging, saved_loglevel = 0;
-	int saved_trap_printk;
 	int got_printf_lock = 0;
 	int retlen = 0;
 	int fnd, len;
@@ -565,8 +564,6 @@
 	unsigned long uninitialized_var(flags);
 
 	preempt_disable();
-	saved_trap_printk = kdb_trap_printk;
-	kdb_trap_printk = 0;
 
 	/* Serialize kdb_printf if multiple cpus try to write at once.
 	 * But if any cpu goes recursive in kdb, just print the output,
@@ -833,7 +830,6 @@
 	} else {
 		__release(kdb_printf_lock);
 	}
-	kdb_trap_printk = saved_trap_printk;
 	preempt_enable();
 	return retlen;
 }
@@ -843,9 +839,11 @@
 	va_list ap;
 	int r;
 
+	kdb_trap_printk++;
 	va_start(ap, fmt);
 	r = vkdb_printf(fmt, ap);
 	va_end(ap);
+	kdb_trap_printk--;
 
 	return r;
 }
diff -Nur linux-3.18.12.orig/kernel/events/core.c linux-3.18.12/kernel/events/core.c
--- linux-3.18.12.orig/kernel/events/core.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/events/core.c	2015-04-26 13:32:22.431684003 -0500
@@ -6346,6 +6346,7 @@
 
 	hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 	hwc->hrtimer.function = perf_swevent_hrtimer;
+	hwc->hrtimer.irqsafe = 1;
 
 	/*
 	 * Since hrtimers have a fixed rate, we can do a static freq->period
diff -Nur linux-3.18.12.orig/kernel/events/core.c.orig linux-3.18.12/kernel/events/core.c.orig
--- linux-3.18.12.orig/kernel/events/core.c.orig	1969-12-31 18:00:00.000000000 -0600
+++ linux-3.18.12/kernel/events/core.c.orig	2015-04-20 14:48:02.000000000 -0500
@@ -0,0 +1,8339 @@
+/*
+ * Performance events core code:
+ *
+ *  Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
+ *  Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
+ *  Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
+ *  Copyright  ©  2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
+ *
+ * For licensing details see kernel-base/COPYING
+ */
+
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/cpu.h>
+#include <linux/smp.h>
+#include <linux/idr.h>
+#include <linux/file.h>
+#include <linux/poll.h>
+#include <linux/slab.h>
+#include <linux/hash.h>
+#include <linux/tick.h>
+#include <linux/sysfs.h>
+#include <linux/dcache.h>
+#include <linux/percpu.h>
+#include <linux/ptrace.h>
+#include <linux/reboot.h>
+#include <linux/vmstat.h>
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/vmalloc.h>
+#include <linux/hardirq.h>
+#include <linux/rculist.h>
+#include <linux/uaccess.h>
+#include <linux/syscalls.h>
+#include <linux/anon_inodes.h>
+#include <linux/kernel_stat.h>
+#include <linux/perf_event.h>
+#include <linux/ftrace_event.h>
+#include <linux/hw_breakpoint.h>
+#include <linux/mm_types.h>
+#include <linux/cgroup.h>
+#include <linux/module.h>
+#include <linux/mman.h>
+#include <linux/compat.h>
+
+#include "internal.h"
+
+#include <asm/irq_regs.h>
+
+static struct workqueue_struct *perf_wq;
+
+struct remote_function_call {
+	struct task_struct	*p;
+	int			(*func)(void *info);
+	void			*info;
+	int			ret;
+};
+
+static void remote_function(void *data)
+{
+	struct remote_function_call *tfc = data;
+	struct task_struct *p = tfc->p;
+
+	if (p) {
+		tfc->ret = -EAGAIN;
+		if (task_cpu(p) != smp_processor_id() || !task_curr(p))
+			return;
+	}
+
+	tfc->ret = tfc->func(tfc->info);
+}
+
+/**
+ * task_function_call - call a function on the cpu on which a task runs
+ * @p:		the task to evaluate
+ * @func:	the function to be called
+ * @info:	the function call argument
+ *
+ * Calls the function @func when the task is currently running. This might
+ * be on the current CPU, which just calls the function directly
+ *
+ * returns: @func return value, or
+ *	    -ESRCH  - when the process isn't running
+ *	    -EAGAIN - when the process moved away
+ */
+static int
+task_function_call(struct task_struct *p, int (*func) (void *info), void *info)
+{
+	struct remote_function_call data = {
+		.p	= p,
+		.func	= func,
+		.info	= info,
+		.ret	= -ESRCH, /* No such (running) process */
+	};
+
+	if (task_curr(p))
+		smp_call_function_single(task_cpu(p), remote_function, &data, 1);
+
+	return data.ret;
+}
+
+/**
+ * cpu_function_call - call a function on the cpu
+ * @func:	the function to be called
+ * @info:	the function call argument
+ *
+ * Calls the function @func on the remote cpu.
+ *
+ * returns: @func return value or -ENXIO when the cpu is offline
+ */
+static int cpu_function_call(int cpu, int (*func) (void *info), void *info)
+{
+	struct remote_function_call data = {
+		.p	= NULL,
+		.func	= func,
+		.info	= info,
+		.ret	= -ENXIO, /* No such CPU */
+	};
+
+	smp_call_function_single(cpu, remote_function, &data, 1);
+
+	return data.ret;
+}
+
+#define EVENT_OWNER_KERNEL ((void *) -1)
+
+static bool is_kernel_event(struct perf_event *event)
+{
+	return event->owner == EVENT_OWNER_KERNEL;
+}
+
+#define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
+		       PERF_FLAG_FD_OUTPUT  |\
+		       PERF_FLAG_PID_CGROUP |\
+		       PERF_FLAG_FD_CLOEXEC)
+
+/*
+ * branch priv levels that need permission checks
+ */
+#define PERF_SAMPLE_BRANCH_PERM_PLM \
+	(PERF_SAMPLE_BRANCH_KERNEL |\
+	 PERF_SAMPLE_BRANCH_HV)
+
+enum event_type_t {
+	EVENT_FLEXIBLE = 0x1,
+	EVENT_PINNED = 0x2,
+	EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED,
+};
+
+/*
+ * perf_sched_events : >0 events exist
+ * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
+ */
+struct static_key_deferred perf_sched_events __read_mostly;
+static DEFINE_PER_CPU(atomic_t, perf_cgroup_events);
+static DEFINE_PER_CPU(atomic_t, perf_branch_stack_events);
+
+static atomic_t nr_mmap_events __read_mostly;
+static atomic_t nr_comm_events __read_mostly;
+static atomic_t nr_task_events __read_mostly;
+static atomic_t nr_freq_events __read_mostly;
+
+static LIST_HEAD(pmus);
+static DEFINE_MUTEX(pmus_lock);
+static struct srcu_struct pmus_srcu;
+
+/*
+ * perf event paranoia level:
+ *  -1 - not paranoid at all
+ *   0 - disallow raw tracepoint access for unpriv
+ *   1 - disallow cpu events for unpriv
+ *   2 - disallow kernel profiling for unpriv
+ */
+int sysctl_perf_event_paranoid __read_mostly = 1;
+
+/* Minimum for 512 kiB + 1 user control page */
+int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */
+
+/*
+ * max perf event sample rate
+ */
+#define DEFAULT_MAX_SAMPLE_RATE		100000
+#define DEFAULT_SAMPLE_PERIOD_NS	(NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
+#define DEFAULT_CPU_TIME_MAX_PERCENT	25
+
+int sysctl_perf_event_sample_rate __read_mostly	= DEFAULT_MAX_SAMPLE_RATE;
+
+static int max_samples_per_tick __read_mostly	= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE, HZ);
+static int perf_sample_period_ns __read_mostly	= DEFAULT_SAMPLE_PERIOD_NS;
+
+static int perf_sample_allowed_ns __read_mostly =
+	DEFAULT_SAMPLE_PERIOD_NS * DEFAULT_CPU_TIME_MAX_PERCENT / 100;
+
+void update_perf_cpu_limits(void)
+{
+	u64 tmp = perf_sample_period_ns;
+
+	tmp *= sysctl_perf_cpu_time_max_percent;
+	do_div(tmp, 100);
+	ACCESS_ONCE(perf_sample_allowed_ns) = tmp;
+}
+
+static int perf_rotate_context(struct perf_cpu_context *cpuctx);
+
+int perf_proc_update_handler(struct ctl_table *table, int write,
+		void __user *buffer, size_t *lenp,
+		loff_t *ppos)
+{
+	int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
+
+	if (ret || !write)
+		return ret;
+
+	max_samples_per_tick = DIV_ROUND_UP(sysctl_perf_event_sample_rate, HZ);
+	perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate;
+	update_perf_cpu_limits();
+
+	return 0;
+}
+
+int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT;
+
+int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write,
+				void __user *buffer, size_t *lenp,
+				loff_t *ppos)
+{
+	int ret = proc_dointvec(table, write, buffer, lenp, ppos);
+
+	if (ret || !write)
+		return ret;
+
+	update_perf_cpu_limits();
+
+	return 0;
+}
+
+/*
+ * perf samples are done in some very critical code paths (NMIs).
+ * If they take too much CPU time, the system can lock up and not
+ * get any real work done.  This will drop the sample rate when
+ * we detect that events are taking too long.
+ */
+#define NR_ACCUMULATED_SAMPLES 128
+static DEFINE_PER_CPU(u64, running_sample_length);
+
+static void perf_duration_warn(struct irq_work *w)
+{
+	u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns);
+	u64 avg_local_sample_len;
+	u64 local_samples_len;
+
+	local_samples_len = __this_cpu_read(running_sample_length);
+	avg_local_sample_len = local_samples_len/NR_ACCUMULATED_SAMPLES;
+
+	printk_ratelimited(KERN_WARNING
+			"perf interrupt took too long (%lld > %lld), lowering "
+			"kernel.perf_event_max_sample_rate to %d\n",
+			avg_local_sample_len, allowed_ns >> 1,
+			sysctl_perf_event_sample_rate);
+}
+
+static DEFINE_IRQ_WORK(perf_duration_work, perf_duration_warn);
+
+void perf_sample_event_took(u64 sample_len_ns)
+{
+	u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns);
+	u64 avg_local_sample_len;
+	u64 local_samples_len;
+
+	if (allowed_ns == 0)
+		return;
+
+	/* decay the counter by 1 average sample */
+	local_samples_len = __this_cpu_read(running_sample_length);
+	local_samples_len -= local_samples_len/NR_ACCUMULATED_SAMPLES;
+	local_samples_len += sample_len_ns;
+	__this_cpu_write(running_sample_length, local_samples_len);
+
+	/*
+	 * note: this will be biased artifically low until we have
+	 * seen NR_ACCUMULATED_SAMPLES.  Doing it this way keeps us
+	 * from having to maintain a count.
+	 */
+	avg_local_sample_len = local_samples_len/NR_ACCUMULATED_SAMPLES;
+
+	if (avg_local_sample_len <= allowed_ns)
+		return;
+
+	if (max_samples_per_tick <= 1)
+		return;
+
+	max_samples_per_tick = DIV_ROUND_UP(max_samples_per_tick, 2);
+	sysctl_perf_event_sample_rate = max_samples_per_tick * HZ;
+	perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate;
+
+	update_perf_cpu_limits();
+
+	if (!irq_work_queue(&perf_duration_work)) {
+		early_printk("perf interrupt took too long (%lld > %lld), lowering "
+			     "kernel.perf_event_max_sample_rate to %d\n",
+			     avg_local_sample_len, allowed_ns >> 1,
+			     sysctl_perf_event_sample_rate);
+	}
+}
+
+static atomic64_t perf_event_id;
+
+static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx,
+			      enum event_type_t event_type);
+
+static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx,
+			     enum event_type_t event_type,
+			     struct task_struct *task);
+
+static void update_context_time(struct perf_event_context *ctx);
+static u64 perf_event_time(struct perf_event *event);
+
+void __weak perf_event_print_debug(void)	{ }
+
+extern __weak const char *perf_pmu_name(void)
+{
+	return "pmu";
+}
+
+static inline u64 perf_clock(void)
+{
+	return local_clock();
+}
+
+static inline struct perf_cpu_context *
+__get_cpu_context(struct perf_event_context *ctx)
+{
+	return this_cpu_ptr(ctx->pmu->pmu_cpu_context);
+}
+
+static void perf_ctx_lock(struct perf_cpu_context *cpuctx,
+			  struct perf_event_context *ctx)
+{
+	raw_spin_lock(&cpuctx->ctx.lock);
+	if (ctx)
+		raw_spin_lock(&ctx->lock);
+}
+
+static void perf_ctx_unlock(struct perf_cpu_context *cpuctx,
+			    struct perf_event_context *ctx)
+{
+	if (ctx)
+		raw_spin_unlock(&ctx->lock);
+	raw_spin_unlock(&cpuctx->ctx.lock);
+}
+
+#ifdef CONFIG_CGROUP_PERF
+
+/*
+ * perf_cgroup_info keeps track of time_enabled for a cgroup.
+ * This is a per-cpu dynamically allocated data structure.
+ */
+struct perf_cgroup_info {
+	u64				time;
+	u64				timestamp;
+};
+
+struct perf_cgroup {
+	struct cgroup_subsys_state	css;
+	struct perf_cgroup_info	__percpu *info;
+};
+
+/*
+ * Must ensure cgroup is pinned (css_get) before calling
+ * this function. In other words, we cannot call this function
+ * if there is no cgroup event for the current CPU context.
+ */
+static inline struct perf_cgroup *
+perf_cgroup_from_task(struct task_struct *task)
+{
+	return container_of(task_css(task, perf_event_cgrp_id),
+			    struct perf_cgroup, css);
+}
+
+static inline bool
+perf_cgroup_match(struct perf_event *event)
+{
+	struct perf_event_context *ctx = event->ctx;
+	struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
+
+	/* @event doesn't care about cgroup */
+	if (!event->cgrp)
+		return true;
+
+	/* wants specific cgroup scope but @cpuctx isn't associated with any */
+	if (!cpuctx->cgrp)
+		return false;
+
+	/*
+	 * Cgroup scoping is recursive.  An event enabled for a cgroup is
+	 * also enabled for all its descendant cgroups.  If @cpuctx's
+	 * cgroup is a descendant of @event's (the test covers identity
+	 * case), it's a match.
+	 */
+	return cgroup_is_descendant(cpuctx->cgrp->css.cgroup,
+				    event->cgrp->css.cgroup);
+}
+
+static inline void perf_detach_cgroup(struct perf_event *event)
+{
+	css_put(&event->cgrp->css);
+	event->cgrp = NULL;
+}
+
+static inline int is_cgroup_event(struct perf_event *event)
+{
+	return event->cgrp != NULL;
+}
+
+static inline u64 perf_cgroup_event_time(struct perf_event *event)
+{
+	struct perf_cgroup_info *t;
+
+	t = per_cpu_ptr(event->cgrp->info, event->cpu);
+	return t->time;
+}
+
+static inline void __update_cgrp_time(struct perf_cgroup *cgrp)
+{
+	struct perf_cgroup_info *info;
+	u64 now;
+
+	now = perf_clock();
+
+	info = this_cpu_ptr(cgrp->info);
+
+	info->time += now - info->timestamp;
+	info->timestamp = now;
+}
+
+static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx)
+{
+	struct perf_cgroup *cgrp_out = cpuctx->cgrp;
+	if (cgrp_out)
+		__update_cgrp_time(cgrp_out);
+}
+
+static inline void update_cgrp_time_from_event(struct perf_event *event)
+{
+	struct perf_cgroup *cgrp;
+
+	/*
+	 * ensure we access cgroup data only when needed and
+	 * when we know the cgroup is pinned (css_get)
+	 */
+	if (!is_cgroup_event(event))
+		return;
+
+	cgrp = perf_cgroup_from_task(current);
+	/*
+	 * Do not update time when cgroup is not active
+	 */
+	if (cgrp == event->cgrp)
+		__update_cgrp_time(event->cgrp);
+}
+
+static inline void
+perf_cgroup_set_timestamp(struct task_struct *task,
+			  struct perf_event_context *ctx)
+{
+	struct perf_cgroup *cgrp;
+	struct perf_cgroup_info *info;
+
+	/*
+	 * ctx->lock held by caller
+	 * ensure we do not access cgroup data
+	 * unless we have the cgroup pinned (css_get)
+	 */
+	if (!task || !ctx->nr_cgroups)
+		return;
+
+	cgrp = perf_cgroup_from_task(task);
+	info = this_cpu_ptr(cgrp->info);
+	info->timestamp = ctx->timestamp;
+}
+
+#define PERF_CGROUP_SWOUT	0x1 /* cgroup switch out every event */
+#define PERF_CGROUP_SWIN	0x2 /* cgroup switch in events based on task */
+
+/*
+ * reschedule events based on the cgroup constraint of task.
+ *
+ * mode SWOUT : schedule out everything
+ * mode SWIN : schedule in based on cgroup for next
+ */
+void perf_cgroup_switch(struct task_struct *task, int mode)
+{
+	struct perf_cpu_context *cpuctx;
+	struct pmu *pmu;
+	unsigned long flags;
+
+	/*
+	 * disable interrupts to avoid geting nr_cgroup
+	 * changes via __perf_event_disable(). Also
+	 * avoids preemption.
+	 */
+	local_irq_save(flags);
+
+	/*
+	 * we reschedule only in the presence of cgroup
+	 * constrained events.
+	 */
+	rcu_read_lock();
+
+	list_for_each_entry_rcu(pmu, &pmus, entry) {
+		cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
+		if (cpuctx->unique_pmu != pmu)
+			continue; /* ensure we process each cpuctx once */
+
+		/*
+		 * perf_cgroup_events says at least one
+		 * context on this CPU has cgroup events.
+		 *
+		 * ctx->nr_cgroups reports the number of cgroup
+		 * events for a context.
+		 */
+		if (cpuctx->ctx.nr_cgroups > 0) {
+			perf_ctx_lock(cpuctx, cpuctx->task_ctx);
+			perf_pmu_disable(cpuctx->ctx.pmu);
+
+			if (mode & PERF_CGROUP_SWOUT) {
+				cpu_ctx_sched_out(cpuctx, EVENT_ALL);
+				/*
+				 * must not be done before ctxswout due
+				 * to event_filter_match() in event_sched_out()
+				 */
+				cpuctx->cgrp = NULL;
+			}
+
+			if (mode & PERF_CGROUP_SWIN) {
+				WARN_ON_ONCE(cpuctx->cgrp);
+				/*
+				 * set cgrp before ctxsw in to allow
+				 * event_filter_match() to not have to pass
+				 * task around
+				 */
+				cpuctx->cgrp = perf_cgroup_from_task(task);
+				cpu_ctx_sched_in(cpuctx, EVENT_ALL, task);
+			}
+			perf_pmu_enable(cpuctx->ctx.pmu);
+			perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
+		}
+	}
+
+	rcu_read_unlock();
+
+	local_irq_restore(flags);
+}
+
+static inline void perf_cgroup_sched_out(struct task_struct *task,
+					 struct task_struct *next)
+{
+	struct perf_cgroup *cgrp1;
+	struct perf_cgroup *cgrp2 = NULL;
+
+	/*
+	 * we come here when we know perf_cgroup_events > 0
+	 */
+	cgrp1 = perf_cgroup_from_task(task);
+
+	/*
+	 * next is NULL when called from perf_event_enable_on_exec()
+	 * that will systematically cause a cgroup_switch()
+	 */
+	if (next)
+		cgrp2 = perf_cgroup_from_task(next);
+
+	/*
+	 * only schedule out current cgroup events if we know
+	 * that we are switching to a different cgroup. Otherwise,
+	 * do no touch the cgroup events.
+	 */
+	if (cgrp1 != cgrp2)
+		perf_cgroup_switch(task, PERF_CGROUP_SWOUT);
+}
+
+static inline void perf_cgroup_sched_in(struct task_struct *prev,
+					struct task_struct *task)
+{
+	struct perf_cgroup *cgrp1;
+	struct perf_cgroup *cgrp2 = NULL;
+
+	/*
+	 * we come here when we know perf_cgroup_events > 0
+	 */
+	cgrp1 = perf_cgroup_from_task(task);
+
+	/* prev can never be NULL */
+	cgrp2 = perf_cgroup_from_task(prev);
+
+	/*
+	 * only need to schedule in cgroup events if we are changing
+	 * cgroup during ctxsw. Cgroup events were not scheduled
+	 * out of ctxsw out if that was not the case.
+	 */
+	if (cgrp1 != cgrp2)
+		perf_cgroup_switch(task, PERF_CGROUP_SWIN);
+}
+
+static inline int perf_cgroup_connect(int fd, struct perf_event *event,
+				      struct perf_event_attr *attr,
+				      struct perf_event *group_leader)
+{
+	struct perf_cgroup *cgrp;
+	struct cgroup_subsys_state *css;
+	struct fd f = fdget(fd);
+	int ret = 0;
+
+	if (!f.file)
+		return -EBADF;
+
+	css = css_tryget_online_from_dir(f.file->f_dentry,
+					 &perf_event_cgrp_subsys);
+	if (IS_ERR(css)) {
+		ret = PTR_ERR(css);
+		goto out;
+	}
+
+	cgrp = container_of(css, struct perf_cgroup, css);
+	event->cgrp = cgrp;
+
+	/*
+	 * all events in a group must monitor
+	 * the same cgroup because a task belongs
+	 * to only one perf cgroup at a time
+	 */
+	if (group_leader && group_leader->cgrp != cgrp) {
+		perf_detach_cgroup(event);
+		ret = -EINVAL;
+	}
+out:
+	fdput(f);
+	return ret;
+}
+
+static inline void
+perf_cgroup_set_shadow_time(struct perf_event *event, u64 now)
+{
+	struct perf_cgroup_info *t;
+	t = per_cpu_ptr(event->cgrp->info, event->cpu);
+	event->shadow_ctx_time = now - t->timestamp;
+}
+
+static inline void
+perf_cgroup_defer_enabled(struct perf_event *event)
+{
+	/*
+	 * when the current task's perf cgroup does not match
+	 * the event's, we need to remember to call the
+	 * perf_mark_enable() function the first time a task with
+	 * a matching perf cgroup is scheduled in.
+	 */
+	if (is_cgroup_event(event) && !perf_cgroup_match(event))
+		event->cgrp_defer_enabled = 1;
+}
+
+static inline void
+perf_cgroup_mark_enabled(struct perf_event *event,
+			 struct perf_event_context *ctx)
+{
+	struct perf_event *sub;
+	u64 tstamp = perf_event_time(event);
+
+	if (!event->cgrp_defer_enabled)
+		return;
+
+	event->cgrp_defer_enabled = 0;
+
+	event->tstamp_enabled = tstamp - event->total_time_enabled;
+	list_for_each_entry(sub, &event->sibling_list, group_entry) {
+		if (sub->state >= PERF_EVENT_STATE_INACTIVE) {
+			sub->tstamp_enabled = tstamp - sub->total_time_enabled;
+			sub->cgrp_defer_enabled = 0;
+		}
+	}
+}
+#else /* !CONFIG_CGROUP_PERF */
+
+static inline bool
+perf_cgroup_match(struct perf_event *event)
+{
+	return true;
+}
+
+static inline void perf_detach_cgroup(struct perf_event *event)
+{}
+
+static inline int is_cgroup_event(struct perf_event *event)
+{
+	return 0;
+}
+
+static inline u64 perf_cgroup_event_cgrp_time(struct perf_event *event)
+{
+	return 0;
+}
+
+static inline void update_cgrp_time_from_event(struct perf_event *event)
+{
+}
+
+static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx)
+{
+}
+
+static inline void perf_cgroup_sched_out(struct task_struct *task,
+					 struct task_struct *next)
+{
+}
+
+static inline void perf_cgroup_sched_in(struct task_struct *prev,
+					struct task_struct *task)
+{
+}
+
+static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event,
+				      struct perf_event_attr *attr,
+				      struct perf_event *group_leader)
+{
+	return -EINVAL;
+}
+
+static inline void
+perf_cgroup_set_timestamp(struct task_struct *task,
+			  struct perf_event_context *ctx)
+{
+}
+
+void
+perf_cgroup_switch(struct task_struct *task, struct task_struct *next)
+{
+}
+
+static inline void
+perf_cgroup_set_shadow_time(struct perf_event *event, u64 now)
+{
+}
+
+static inline u64 perf_cgroup_event_time(struct perf_event *event)
+{
+	return 0;
+}
+
+static inline void
+perf_cgroup_defer_enabled(struct perf_event *event)
+{
+}
+
+static inline void
+perf_cgroup_mark_enabled(struct perf_event *event,
+			 struct perf_event_context *ctx)
+{
+}
+#endif
+
+/*
+ * set default to be dependent on timer tick just
+ * like original code
+ */
+#define PERF_CPU_HRTIMER (1000 / HZ)
+/*
+ * function must be called with interrupts disbled
+ */
+static enum hrtimer_restart perf_cpu_hrtimer_handler(struct hrtimer *hr)
+{
+	struct perf_cpu_context *cpuctx;
+	enum hrtimer_restart ret = HRTIMER_NORESTART;
+	int rotations = 0;
+
+	WARN_ON(!irqs_disabled());
+
+	cpuctx = container_of(hr, struct perf_cpu_context, hrtimer);
+
+	rotations = perf_rotate_context(cpuctx);
+
+	/*
+	 * arm timer if needed
+	 */
+	if (rotations) {
+		hrtimer_forward_now(hr, cpuctx->hrtimer_interval);
+		ret = HRTIMER_RESTART;
+	}
+
+	return ret;
+}
+
+/* CPU is going down */
+void perf_cpu_hrtimer_cancel(int cpu)
+{
+	struct perf_cpu_context *cpuctx;
+	struct pmu *pmu;
+	unsigned long flags;
+
+	if (WARN_ON(cpu != smp_processor_id()))
+		return;
+
+	local_irq_save(flags);
+
+	rcu_read_lock();
+
+	list_for_each_entry_rcu(pmu, &pmus, entry) {
+		cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
+
+		if (pmu->task_ctx_nr == perf_sw_context)
+			continue;
+
+		hrtimer_cancel(&cpuctx->hrtimer);
+	}
+
+	rcu_read_unlock();
+
+	local_irq_restore(flags);
+}
+
+static void __perf_cpu_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu)
+{
+	struct hrtimer *hr = &cpuctx->hrtimer;
+	struct pmu *pmu = cpuctx->ctx.pmu;
+	int timer;
+
+	/* no multiplexing needed for SW PMU */
+	if (pmu->task_ctx_nr == perf_sw_context)
+		return;
+
+	/*
+	 * check default is sane, if not set then force to
+	 * default interval (1/tick)
+	 */
+	timer = pmu->hrtimer_interval_ms;
+	if (timer < 1)
+		timer = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER;
+
+	cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer);
+
+	hrtimer_init(hr, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED);
+	hr->function = perf_cpu_hrtimer_handler;
+}
+
+static void perf_cpu_hrtimer_restart(struct perf_cpu_context *cpuctx)
+{
+	struct hrtimer *hr = &cpuctx->hrtimer;
+	struct pmu *pmu = cpuctx->ctx.pmu;
+
+	/* not for SW PMU */
+	if (pmu->task_ctx_nr == perf_sw_context)
+		return;
+
+	if (hrtimer_active(hr))
+		return;
+
+	if (!hrtimer_callback_running(hr))
+		__hrtimer_start_range_ns(hr, cpuctx->hrtimer_interval,
+					 0, HRTIMER_MODE_REL_PINNED, 0);
+}
+
+void perf_pmu_disable(struct pmu *pmu)
+{
+	int *count = this_cpu_ptr(pmu->pmu_disable_count);
+	if (!(*count)++)
+		pmu->pmu_disable(pmu);
+}
+
+void perf_pmu_enable(struct pmu *pmu)
+{
+	int *count = this_cpu_ptr(pmu->pmu_disable_count);
+	if (!--(*count))
+		pmu->pmu_enable(pmu);
+}
+
+static DEFINE_PER_CPU(struct list_head, rotation_list);
+
+/*
+ * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
+ * because they're strictly cpu affine and rotate_start is called with IRQs
+ * disabled, while rotate_context is called from IRQ context.
+ */
+static void perf_pmu_rotate_start(struct pmu *pmu)
+{
+	struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
+	struct list_head *head = this_cpu_ptr(&rotation_list);
+
+	WARN_ON(!irqs_disabled());
+
+	if (list_empty(&cpuctx->rotation_list))
+		list_add(&cpuctx->rotation_list, head);
+}
+
+static void get_ctx(struct perf_event_context *ctx)
+{
+	WARN_ON(!atomic_inc_not_zero(&ctx->refcount));
+}
+
+static void put_ctx(struct perf_event_context *ctx)
+{
+	if (atomic_dec_and_test(&ctx->refcount)) {
+		if (ctx->parent_ctx)
+			put_ctx(ctx->parent_ctx);
+		if (ctx->task)
+			put_task_struct(ctx->task);
+		kfree_rcu(ctx, rcu_head);
+	}
+}
+
+/*
+ * This must be done under the ctx->lock, such as to serialize against
+ * context_equiv(), therefore we cannot call put_ctx() since that might end up
+ * calling scheduler related locks and ctx->lock nests inside those.
+ */
+static __must_check struct perf_event_context *
+unclone_ctx(struct perf_event_context *ctx)
+{
+	struct perf_event_context *parent_ctx = ctx->parent_ctx;
+
+	lockdep_assert_held(&ctx->lock);
+
+	if (parent_ctx)
+		ctx->parent_ctx = NULL;
+	ctx->generation++;
+
+	return parent_ctx;
+}
+
+static u32 perf_event_pid(struct perf_event *event, struct task_struct *p)
+{
+	/*
+	 * only top level events have the pid namespace they were created in
+	 */
+	if (event->parent)
+		event = event->parent;
+
+	return task_tgid_nr_ns(p, event->ns);
+}
+
+static u32 perf_event_tid(struct perf_event *event, struct task_struct *p)
+{
+	/*
+	 * only top level events have the pid namespace they were created in
+	 */
+	if (event->parent)
+		event = event->parent;
+
+	return task_pid_nr_ns(p, event->ns);
+}
+
+/*
+ * If we inherit events we want to return the parent event id
+ * to userspace.
+ */
+static u64 primary_event_id(struct perf_event *event)
+{
+	u64 id = event->id;
+
+	if (event->parent)
+		id = event->parent->id;
+
+	return id;
+}
+
+/*
+ * Get the perf_event_context for a task and lock it.
+ * This has to cope with with the fact that until it is locked,
+ * the context could get moved to another task.
+ */
+static struct perf_event_context *
+perf_lock_task_context(struct task_struct *task, int ctxn, unsigned long *flags)
+{
+	struct perf_event_context *ctx;
+
+retry:
+	/*
+	 * One of the few rules of preemptible RCU is that one cannot do
+	 * rcu_read_unlock() while holding a scheduler (or nested) lock when
+	 * part of the read side critical section was preemptible -- see
+	 * rcu_read_unlock_special().
+	 *
+	 * Since ctx->lock nests under rq->lock we must ensure the entire read
+	 * side critical section is non-preemptible.
+	 */
+	preempt_disable();
+	rcu_read_lock();
+	ctx = rcu_dereference(task->perf_event_ctxp[ctxn]);
+	if (ctx) {
+		/*
+		 * If this context is a clone of another, it might
+		 * get swapped for another underneath us by
+		 * perf_event_task_sched_out, though the
+		 * rcu_read_lock() protects us from any context
+		 * getting freed.  Lock the context and check if it
+		 * got swapped before we could get the lock, and retry
+		 * if so.  If we locked the right context, then it
+		 * can't get swapped on us any more.
+		 */
+		raw_spin_lock_irqsave(&ctx->lock, *flags);
+		if (ctx != rcu_dereference(task->perf_event_ctxp[ctxn])) {
+			raw_spin_unlock_irqrestore(&ctx->lock, *flags);
+			rcu_read_unlock();
+			preempt_enable();
+			goto retry;
+		}
+
+		if (!atomic_inc_not_zero(&ctx->refcount)) {
+			raw_spin_unlock_irqrestore(&ctx->lock, *flags);
+			ctx = NULL;
+		}
+	}
+	rcu_read_unlock();
+	preempt_enable();
+	return ctx;
+}
+
+/*
+ * Get the context for a task and increment its pin_count so it
+ * can't get swapped to another task.  This also increments its
+ * reference count so that the context can't get freed.
+ */
+static struct perf_event_context *
+perf_pin_task_context(struct task_struct *task, int ctxn)
+{
+	struct perf_event_context *ctx;
+	unsigned long flags;
+
+	ctx = perf_lock_task_context(task, ctxn, &flags);
+	if (ctx) {
+		++ctx->pin_count;
+		raw_spin_unlock_irqrestore(&ctx->lock, flags);
+	}
+	return ctx;
+}
+
+static void perf_unpin_context(struct perf_event_context *ctx)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&ctx->lock, flags);
+	--ctx->pin_count;
+	raw_spin_unlock_irqrestore(&ctx->lock, flags);
+}
+
+/*
+ * Update the record of the current time in a context.
+ */
+static void update_context_time(struct perf_event_context *ctx)
+{
+	u64 now = perf_clock();
+
+	ctx->time += now - ctx->timestamp;
+	ctx->timestamp = now;
+}
+
+static u64 perf_event_time(struct perf_event *event)
+{
+	struct perf_event_context *ctx = event->ctx;
+
+	if (is_cgroup_event(event))
+		return perf_cgroup_event_time(event);
+
+	return ctx ? ctx->time : 0;
+}
+
+/*
+ * Update the total_time_enabled and total_time_running fields for a event.
+ * The caller of this function needs to hold the ctx->lock.
+ */
+static void update_event_times(struct perf_event *event)
+{
+	struct perf_event_context *ctx = event->ctx;
+	u64 run_end;
+
+	if (event->state < PERF_EVENT_STATE_INACTIVE ||
+	    event->group_leader->state < PERF_EVENT_STATE_INACTIVE)
+		return;
+	/*
+	 * in cgroup mode, time_enabled represents
+	 * the time the event was enabled AND active
+	 * tasks were in the monitored cgroup. This is
+	 * independent of the activity of the context as
+	 * there may be a mix of cgroup and non-cgroup events.
+	 *
+	 * That is why we treat cgroup events differently
+	 * here.
+	 */
+	if (is_cgroup_event(event))
+		run_end = perf_cgroup_event_time(event);
+	else if (ctx->is_active)
+		run_end = ctx->time;
+	else
+		run_end = event->tstamp_stopped;
+
+	event->total_time_enabled = run_end - event->tstamp_enabled;
+
+	if (event->state == PERF_EVENT_STATE_INACTIVE)
+		run_end = event->tstamp_stopped;
+	else
+		run_end = perf_event_time(event);
+
+	event->total_time_running = run_end - event->tstamp_running;
+
+}
+
+/*
+ * Update total_time_enabled and total_time_running for all events in a group.
+ */
+static void update_group_times(struct perf_event *leader)
+{
+	struct perf_event *event;
+
+	update_event_times(leader);
+	list_for_each_entry(event, &leader->sibling_list, group_entry)
+		update_event_times(event);
+}
+
+static struct list_head *
+ctx_group_list(struct perf_event *event, struct perf_event_context *ctx)
+{
+	if (event->attr.pinned)
+		return &ctx->pinned_groups;
+	else
+		return &ctx->flexible_groups;
+}
+
+/*
+ * Add a event from the lists for its context.
+ * Must be called with ctx->mutex and ctx->lock held.
+ */
+static void
+list_add_event(struct perf_event *event, struct perf_event_context *ctx)
+{
+	WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT);
+	event->attach_state |= PERF_ATTACH_CONTEXT;
+
+	/*
+	 * If we're a stand alone event or group leader, we go to the context
+	 * list, group events are kept attached to the group so that
+	 * perf_group_detach can, at all times, locate all siblings.
+	 */
+	if (event->group_leader == event) {
+		struct list_head *list;
+
+		if (is_software_event(event))
+			event->group_flags |= PERF_GROUP_SOFTWARE;
+
+		list = ctx_group_list(event, ctx);
+		list_add_tail(&event->group_entry, list);
+	}
+
+	if (is_cgroup_event(event))
+		ctx->nr_cgroups++;
+
+	if (has_branch_stack(event))
+		ctx->nr_branch_stack++;
+
+	list_add_rcu(&event->event_entry, &ctx->event_list);
+	if (!ctx->nr_events)
+		perf_pmu_rotate_start(ctx->pmu);
+	ctx->nr_events++;
+	if (event->attr.inherit_stat)
+		ctx->nr_stat++;
+
+	ctx->generation++;
+}
+
+/*
+ * Initialize event state based on the perf_event_attr::disabled.
+ */
+static inline void perf_event__state_init(struct perf_event *event)
+{
+	event->state = event->attr.disabled ? PERF_EVENT_STATE_OFF :
+					      PERF_EVENT_STATE_INACTIVE;
+}
+
+/*
+ * Called at perf_event creation and when events are attached/detached from a
+ * group.
+ */
+static void perf_event__read_size(struct perf_event *event)
+{
+	int entry = sizeof(u64); /* value */
+	int size = 0;
+	int nr = 1;
+
+	if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
+		size += sizeof(u64);
+
+	if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
+		size += sizeof(u64);
+
+	if (event->attr.read_format & PERF_FORMAT_ID)
+		entry += sizeof(u64);
+
+	if (event->attr.read_format & PERF_FORMAT_GROUP) {
+		nr += event->group_leader->nr_siblings;
+		size += sizeof(u64);
+	}
+
+	size += entry * nr;
+	event->read_size = size;
+}
+
+static void perf_event__header_size(struct perf_event *event)
+{
+	struct perf_sample_data *data;
+	u64 sample_type = event->attr.sample_type;
+	u16 size = 0;
+
+	perf_event__read_size(event);
+
+	if (sample_type & PERF_SAMPLE_IP)
+		size += sizeof(data->ip);
+
+	if (sample_type & PERF_SAMPLE_ADDR)
+		size += sizeof(data->addr);
+
+	if (sample_type & PERF_SAMPLE_PERIOD)
+		size += sizeof(data->period);
+
+	if (sample_type & PERF_SAMPLE_WEIGHT)
+		size += sizeof(data->weight);
+
+	if (sample_type & PERF_SAMPLE_READ)
+		size += event->read_size;
+
+	if (sample_type & PERF_SAMPLE_DATA_SRC)
+		size += sizeof(data->data_src.val);
+
+	if (sample_type & PERF_SAMPLE_TRANSACTION)
+		size += sizeof(data->txn);
+
+	event->header_size = size;
+}
+
+static void perf_event__id_header_size(struct perf_event *event)
+{
+	struct perf_sample_data *data;
+	u64 sample_type = event->attr.sample_type;
+	u16 size = 0;
+
+	if (sample_type & PERF_SAMPLE_TID)
+		size += sizeof(data->tid_entry);
+
+	if (sample_type & PERF_SAMPLE_TIME)
+		size += sizeof(data->time);
+
+	if (sample_type & PERF_SAMPLE_IDENTIFIER)
+		size += sizeof(data->id);
+
+	if (sample_type & PERF_SAMPLE_ID)
+		size += sizeof(data->id);
+
+	if (sample_type & PERF_SAMPLE_STREAM_ID)
+		size += sizeof(data->stream_id);
+
+	if (sample_type & PERF_SAMPLE_CPU)
+		size += sizeof(data->cpu_entry);
+
+	event->id_header_size = size;
+}
+
+static void perf_group_attach(struct perf_event *event)
+{
+	struct perf_event *group_leader = event->group_leader, *pos;
+
+	/*
+	 * We can have double attach due to group movement in perf_event_open.
+	 */
+	if (event->attach_state & PERF_ATTACH_GROUP)
+		return;
+
+	event->attach_state |= PERF_ATTACH_GROUP;
+
+	if (group_leader == event)
+		return;
+
+	if (group_leader->group_flags & PERF_GROUP_SOFTWARE &&
+			!is_software_event(event))
+		group_leader->group_flags &= ~PERF_GROUP_SOFTWARE;
+
+	list_add_tail(&event->group_entry, &group_leader->sibling_list);
+	group_leader->nr_siblings++;
+
+	perf_event__header_size(group_leader);
+
+	list_for_each_entry(pos, &group_leader->sibling_list, group_entry)
+		perf_event__header_size(pos);
+}
+
+/*
+ * Remove a event from the lists for its context.
+ * Must be called with ctx->mutex and ctx->lock held.
+ */
+static void
+list_del_event(struct perf_event *event, struct perf_event_context *ctx)
+{
+	struct perf_cpu_context *cpuctx;
+	/*
+	 * We can have double detach due to exit/hot-unplug + close.
+	 */
+	if (!(event->attach_state & PERF_ATTACH_CONTEXT))
+		return;
+
+	event->attach_state &= ~PERF_ATTACH_CONTEXT;
+
+	if (is_cgroup_event(event)) {
+		ctx->nr_cgroups--;
+		cpuctx = __get_cpu_context(ctx);
+		/*
+		 * if there are no more cgroup events
+		 * then cler cgrp to avoid stale pointer
+		 * in update_cgrp_time_from_cpuctx()
+		 */
+		if (!ctx->nr_cgroups)
+			cpuctx->cgrp = NULL;
+	}
+
+	if (has_branch_stack(event))
+		ctx->nr_branch_stack--;
+
+	ctx->nr_events--;
+	if (event->attr.inherit_stat)
+		ctx->nr_stat--;
+
+	list_del_rcu(&event->event_entry);
+
+	if (event->group_leader == event)
+		list_del_init(&event->group_entry);
+
+	update_group_times(event);
+
+	/*
+	 * If event was in error state, then keep it
+	 * that way, otherwise bogus counts will be
+	 * returned on read(). The only way to get out
+	 * of error state is by explicit re-enabling
+	 * of the event
+	 */
+	if (event->state > PERF_EVENT_STATE_OFF)
+		event->state = PERF_EVENT_STATE_OFF;
+
+	ctx->generation++;
+}
+
+static void perf_group_detach(struct perf_event *event)
+{
+	struct perf_event *sibling, *tmp;
+	struct list_head *list = NULL;
+
+	/*
+	 * We can have double detach due to exit/hot-unplug + close.
+	 */
+	if (!(event->attach_state & PERF_ATTACH_GROUP))
+		return;
+
+	event->attach_state &= ~PERF_ATTACH_GROUP;
+
+	/*
+	 * If this is a sibling, remove it from its group.
+	 */
+	if (event->group_leader != event) {
+		list_del_init(&event->group_entry);
+		event->group_leader->nr_siblings--;
+		goto out;
+	}
+
+	if (!list_empty(&event->group_entry))
+		list = &event->group_entry;
+
+	/*
+	 * If this was a group event with sibling events then
+	 * upgrade the siblings to singleton events by adding them
+	 * to whatever list we are on.
+	 */
+	list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) {
+		if (list)
+			list_move_tail(&sibling->group_entry, list);
+		sibling->group_leader = sibling;
+
+		/* Inherit group flags from the previous leader */
+		sibling->group_flags = event->group_flags;
+	}
+
+out:
+	perf_event__header_size(event->group_leader);
+
+	list_for_each_entry(tmp, &event->group_leader->sibling_list, group_entry)
+		perf_event__header_size(tmp);
+}
+
+/*
+ * User event without the task.
+ */
+static bool is_orphaned_event(struct perf_event *event)
+{
+	return event && !is_kernel_event(event) && !event->owner;
+}
+
+/*
+ * Event has a parent but parent's task finished and it's
+ * alive only because of children holding refference.
+ */
+static bool is_orphaned_child(struct perf_event *event)
+{
+	return is_orphaned_event(event->parent);
+}
+
+static void orphans_remove_work(struct work_struct *work);
+
+static void schedule_orphans_remove(struct perf_event_context *ctx)
+{
+	if (!ctx->task || ctx->orphans_remove_sched || !perf_wq)
+		return;
+
+	if (queue_delayed_work(perf_wq, &ctx->orphans_remove, 1)) {
+		get_ctx(ctx);
+		ctx->orphans_remove_sched = true;
+	}
+}
+
+static int __init perf_workqueue_init(void)
+{
+	perf_wq = create_singlethread_workqueue("perf");
+	WARN(!perf_wq, "failed to create perf workqueue\n");
+	return perf_wq ? 0 : -1;
+}
+
+core_initcall(perf_workqueue_init);
+
+static inline int
+event_filter_match(struct perf_event *event)
+{
+	return (event->cpu == -1 || event->cpu == smp_processor_id())
+	    && perf_cgroup_match(event);
+}
+
+static void
+event_sched_out(struct perf_event *event,
+		  struct perf_cpu_context *cpuctx,
+		  struct perf_event_context *ctx)
+{
+	u64 tstamp = perf_event_time(event);
+	u64 delta;
+	/*
+	 * An event which could not be activated because of
+	 * filter mismatch still needs to have its timings
+	 * maintained, otherwise bogus information is return
+	 * via read() for time_enabled, time_running:
+	 */
+	if (event->state == PERF_EVENT_STATE_INACTIVE
+	    && !event_filter_match(event)) {
+		delta = tstamp - event->tstamp_stopped;
+		event->tstamp_running += delta;
+		event->tstamp_stopped = tstamp;
+	}
+
+	if (event->state != PERF_EVENT_STATE_ACTIVE)
+		return;
+
+	perf_pmu_disable(event->pmu);
+
+	event->state = PERF_EVENT_STATE_INACTIVE;
+	if (event->pending_disable) {
+		event->pending_disable = 0;
+		event->state = PERF_EVENT_STATE_OFF;
+	}
+	event->tstamp_stopped = tstamp;
+	event->pmu->del(event, 0);
+	event->oncpu = -1;
+
+	if (!is_software_event(event))
+		cpuctx->active_oncpu--;
+	ctx->nr_active--;
+	if (event->attr.freq && event->attr.sample_freq)
+		ctx->nr_freq--;
+	if (event->attr.exclusive || !cpuctx->active_oncpu)
+		cpuctx->exclusive = 0;
+
+	if (is_orphaned_child(event))
+		schedule_orphans_remove(ctx);
+
+	perf_pmu_enable(event->pmu);
+}
+
+static void
+group_sched_out(struct perf_event *group_event,
+		struct perf_cpu_context *cpuctx,
+		struct perf_event_context *ctx)
+{
+	struct perf_event *event;
+	int state = group_event->state;
+
+	event_sched_out(group_event, cpuctx, ctx);
+
+	/*
+	 * Schedule out siblings (if any):
+	 */
+	list_for_each_entry(event, &group_event->sibling_list, group_entry)
+		event_sched_out(event, cpuctx, ctx);
+
+	if (state == PERF_EVENT_STATE_ACTIVE && group_event->attr.exclusive)
+		cpuctx->exclusive = 0;
+}
+
+struct remove_event {
+	struct perf_event *event;
+	bool detach_group;
+};
+
+/*
+ * Cross CPU call to remove a performance event
+ *
+ * We disable the event on the hardware level first. After that we
+ * remove it from the context list.
+ */
+static int __perf_remove_from_context(void *info)
+{
+	struct remove_event *re = info;
+	struct perf_event *event = re->event;
+	struct perf_event_context *ctx = event->ctx;
+	struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
+
+	raw_spin_lock(&ctx->lock);
+	event_sched_out(event, cpuctx, ctx);
+	if (re->detach_group)
+		perf_group_detach(event);
+	list_del_event(event, ctx);
+	if (!ctx->nr_events && cpuctx->task_ctx == ctx) {
+		ctx->is_active = 0;
+		cpuctx->task_ctx = NULL;
+	}
+	raw_spin_unlock(&ctx->lock);
+
+	return 0;
+}
+
+
+/*
+ * Remove the event from a task's (or a CPU's) list of events.
+ *
+ * CPU events are removed with a smp call. For task events we only
+ * call when the task is on a CPU.
+ *
+ * If event->ctx is a cloned context, callers must make sure that
+ * every task struct that event->ctx->task could possibly point to
+ * remains valid.  This is OK when called from perf_release since
+ * that only calls us on the top-level context, which can't be a clone.
+ * When called from perf_event_exit_task, it's OK because the
+ * context has been detached from its task.
+ */
+static void perf_remove_from_context(struct perf_event *event, bool detach_group)
+{
+	struct perf_event_context *ctx = event->ctx;
+	struct task_struct *task = ctx->task;
+	struct remove_event re = {
+		.event = event,
+		.detach_group = detach_group,
+	};
+
+	lockdep_assert_held(&ctx->mutex);
+
+	if (!task) {
+		/*
+		 * Per cpu events are removed via an smp call. The removal can
+		 * fail if the CPU is currently offline, but in that case we
+		 * already called __perf_remove_from_context from
+		 * perf_event_exit_cpu.
+		 */
+		cpu_function_call(event->cpu, __perf_remove_from_context, &re);
+		return;
+	}
+
+retry:
+	if (!task_function_call(task, __perf_remove_from_context, &re))
+		return;
+
+	raw_spin_lock_irq(&ctx->lock);
+	/*
+	 * If we failed to find a running task, but find the context active now
+	 * that we've acquired the ctx->lock, retry.
+	 */
+	if (ctx->is_active) {
+		raw_spin_unlock_irq(&ctx->lock);
+		/*
+		 * Reload the task pointer, it might have been changed by
+		 * a concurrent perf_event_context_sched_out().
+		 */
+		task = ctx->task;
+		goto retry;
+	}
+
+	/*
+	 * Since the task isn't running, its safe to remove the event, us
+	 * holding the ctx->lock ensures the task won't get scheduled in.
+	 */
+	if (detach_group)
+		perf_group_detach(event);
+	list_del_event(event, ctx);
+	raw_spin_unlock_irq(&ctx->lock);
+}
+
+/*
+ * Cross CPU call to disable a performance event
+ */
+int __perf_event_disable(void *info)
+{
+	struct perf_event *event = info;
+	struct perf_event_context *ctx = event->ctx;
+	struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
+
+	/*
+	 * If this is a per-task event, need to check whether this
+	 * event's task is the current task on this cpu.
+	 *
+	 * Can trigger due to concurrent perf_event_context_sched_out()
+	 * flipping contexts around.
+	 */
+	if (ctx->task && cpuctx->task_ctx != ctx)
+		return -EINVAL;
+
+	raw_spin_lock(&ctx->lock);
+
+	/*
+	 * If the event is on, turn it off.
+	 * If it is in error state, leave it in error state.
+	 */
+	if (event->state >= PERF_EVENT_STATE_INACTIVE) {
+		update_context_time(ctx);
+		update_cgrp_time_from_event(event);
+		update_group_times(event);
+		if (event == event->group_leader)
+			group_sched_out(event, cpuctx, ctx);
+		else
+			event_sched_out(event, cpuctx, ctx);
+		event->state = PERF_EVENT_STATE_OFF;
+	}
+
+	raw_spin_unlock(&ctx->lock);
+
+	return 0;
+}
+
+/*
+ * Disable a event.
+ *
+ * If event->ctx is a cloned context, callers must make sure that
+ * every task struct that event->ctx->task could possibly point to
+ * remains valid.  This condition is satisifed when called through
+ * perf_event_for_each_child or perf_event_for_each because they
+ * hold the top-level event's child_mutex, so any descendant that
+ * goes to exit will block in sync_child_event.
+ * When called from perf_pending_event it's OK because event->ctx
+ * is the current context on this CPU and preemption is disabled,
+ * hence we can't get into perf_event_task_sched_out for this context.
+ */
+void perf_event_disable(struct perf_event *event)
+{
+	struct perf_event_context *ctx = event->ctx;
+	struct task_struct *task = ctx->task;
+
+	if (!task) {
+		/*
+		 * Disable the event on the cpu that it's on
+		 */
+		cpu_function_call(event->cpu, __perf_event_disable, event);
+		return;
+	}
+
+retry:
+	if (!task_function_call(task, __perf_event_disable, event))
+		return;
+
+	raw_spin_lock_irq(&ctx->lock);
+	/*
+	 * If the event is still active, we need to retry the cross-call.
+	 */
+	if (event->state == PERF_EVENT_STATE_ACTIVE) {
+		raw_spin_unlock_irq(&ctx->lock);
+		/*
+		 * Reload the task pointer, it might have been changed by
+		 * a concurrent perf_event_context_sched_out().
+		 */
+		task = ctx->task;
+		goto retry;
+	}
+
+	/*
+	 * Since we have the lock this context can't be scheduled
+	 * in, so we can change the state safely.
+	 */
+	if (event->state == PERF_EVENT_STATE_INACTIVE) {
+		update_group_times(event);
+		event->state = PERF_EVENT_STATE_OFF;
+	}
+	raw_spin_unlock_irq(&ctx->lock);
+}
+EXPORT_SYMBOL_GPL(perf_event_disable);
+
+static void perf_set_shadow_time(struct perf_event *event,
+				 struct perf_event_context *ctx,
+				 u64 tstamp)
+{
+	/*
+	 * use the correct time source for the time snapshot
+	 *
+	 * We could get by without this by leveraging the
+	 * fact that to get to this function, the caller
+	 * has most likely already called update_context_time()
+	 * and update_cgrp_time_xx() and thus both timestamp
+	 * are identical (or very close). Given that tstamp is,
+	 * already adjusted for cgroup, we could say that:
+	 *    tstamp - ctx->timestamp
+	 * is equivalent to
+	 *    tstamp - cgrp->timestamp.
+	 *
+	 * Then, in perf_output_read(), the calculation would
+	 * work with no changes because:
+	 * - event is guaranteed scheduled in
+	 * - no scheduled out in between
+	 * - thus the timestamp would be the same
+	 *
+	 * But this is a bit hairy.
+	 *
+	 * So instead, we have an explicit cgroup call to remain
+	 * within the time time source all along. We believe it
+	 * is cleaner and simpler to understand.
+	 */
+	if (is_cgroup_event(event))
+		perf_cgroup_set_shadow_time(event, tstamp);
+	else
+		event->shadow_ctx_time = tstamp - ctx->timestamp;
+}
+
+#define MAX_INTERRUPTS (~0ULL)
+
+static void perf_log_throttle(struct perf_event *event, int enable);
+
+static int
+event_sched_in(struct perf_event *event,
+		 struct perf_cpu_context *cpuctx,
+		 struct perf_event_context *ctx)
+{
+	u64 tstamp = perf_event_time(event);
+	int ret = 0;
+
+	lockdep_assert_held(&ctx->lock);
+
+	if (event->state <= PERF_EVENT_STATE_OFF)
+		return 0;
+
+	event->state = PERF_EVENT_STATE_ACTIVE;
+	event->oncpu = smp_processor_id();
+
+	/*
+	 * Unthrottle events, since we scheduled we might have missed several
+	 * ticks already, also for a heavily scheduling task there is little
+	 * guarantee it'll get a tick in a timely manner.
+	 */
+	if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) {
+		perf_log_throttle(event, 1);
+		event->hw.interrupts = 0;
+	}
+
+	/*
+	 * The new state must be visible before we turn it on in the hardware:
+	 */
+	smp_wmb();
+
+	perf_pmu_disable(event->pmu);
+
+	if (event->pmu->add(event, PERF_EF_START)) {
+		event->state = PERF_EVENT_STATE_INACTIVE;
+		event->oncpu = -1;
+		ret = -EAGAIN;
+		goto out;
+	}
+
+	event->tstamp_running += tstamp - event->tstamp_stopped;
+
+	perf_set_shadow_time(event, ctx, tstamp);
+
+	if (!is_software_event(event))
+		cpuctx->active_oncpu++;
+	ctx->nr_active++;
+	if (event->attr.freq && event->attr.sample_freq)
+		ctx->nr_freq++;
+
+	if (event->attr.exclusive)
+		cpuctx->exclusive = 1;
+
+	if (is_orphaned_child(event))
+		schedule_orphans_remove(ctx);
+
+out:
+	perf_pmu_enable(event->pmu);
+
+	return ret;
+}
+
+static int
+group_sched_in(struct perf_event *group_event,
+	       struct perf_cpu_context *cpuctx,
+	       struct perf_event_context *ctx)
+{
+	struct perf_event *event, *partial_group = NULL;
+	struct pmu *pmu = ctx->pmu;
+	u64 now = ctx->time;
+	bool simulate = false;
+
+	if (group_event->state == PERF_EVENT_STATE_OFF)
+		return 0;
+
+	pmu->start_txn(pmu);
+
+	if (event_sched_in(group_event, cpuctx, ctx)) {
+		pmu->cancel_txn(pmu);
+		perf_cpu_hrtimer_restart(cpuctx);
+		return -EAGAIN;
+	}
+
+	/*
+	 * Schedule in siblings as one group (if any):
+	 */
+	list_for_each_entry(event, &group_event->sibling_list, group_entry) {
+		if (event_sched_in(event, cpuctx, ctx)) {
+			partial_group = event;
+			goto group_error;
+		}
+	}
+
+	if (!pmu->commit_txn(pmu))
+		return 0;
+
+group_error:
+	/*
+	 * Groups can be scheduled in as one unit only, so undo any
+	 * partial group before returning:
+	 * The events up to the failed event are scheduled out normally,
+	 * tstamp_stopped will be updated.
+	 *
+	 * The failed events and the remaining siblings need to have
+	 * their timings updated as if they had gone thru event_sched_in()
+	 * and event_sched_out(). This is required to get consistent timings
+	 * across the group. This also takes care of the case where the group
+	 * could never be scheduled by ensuring tstamp_stopped is set to mark
+	 * the time the event was actually stopped, such that time delta
+	 * calculation in update_event_times() is correct.
+	 */
+	list_for_each_entry(event, &group_event->sibling_list, group_entry) {
+		if (event == partial_group)
+			simulate = true;
+
+		if (simulate) {
+			event->tstamp_running += now - event->tstamp_stopped;
+			event->tstamp_stopped = now;
+		} else {
+			event_sched_out(event, cpuctx, ctx);
+		}
+	}
+	event_sched_out(group_event, cpuctx, ctx);
+
+	pmu->cancel_txn(pmu);
+
+	perf_cpu_hrtimer_restart(cpuctx);
+
+	return -EAGAIN;
+}
+
+/*
+ * Work out whether we can put this event group on the CPU now.
+ */
+static int group_can_go_on(struct perf_event *event,
+			   struct perf_cpu_context *cpuctx,
+			   int can_add_hw)
+{
+	/*
+	 * Groups consisting entirely of software events can always go on.
+	 */
+	if (event->group_flags & PERF_GROUP_SOFTWARE)
+		return 1;
+	/*
+	 * If an exclusive group is already on, no other hardware
+	 * events can go on.
+	 */
+	if (cpuctx->exclusive)
+		return 0;
+	/*
+	 * If this group is exclusive and there are already
+	 * events on the CPU, it can't go on.
+	 */
+	if (event->attr.exclusive && cpuctx->active_oncpu)
+		return 0;
+	/*
+	 * Otherwise, try to add it if all previous groups were able
+	 * to go on.
+	 */
+	return can_add_hw;
+}
+
+static void add_event_to_ctx(struct perf_event *event,
+			       struct perf_event_context *ctx)
+{
+	u64 tstamp = perf_event_time(event);
+
+	list_add_event(event, ctx);
+	perf_group_attach(event);
+	event->tstamp_enabled = tstamp;
+	event->tstamp_running = tstamp;
+	event->tstamp_stopped = tstamp;
+}
+
+static void task_ctx_sched_out(struct perf_event_context *ctx);
+static void
+ctx_sched_in(struct perf_event_context *ctx,
+	     struct perf_cpu_context *cpuctx,
+	     enum event_type_t event_type,
+	     struct task_struct *task);
+
+static void perf_event_sched_in(struct perf_cpu_context *cpuctx,
+				struct perf_event_context *ctx,
+				struct task_struct *task)
+{
+	cpu_ctx_sched_in(cpuctx, EVENT_PINNED, task);
+	if (ctx)
+		ctx_sched_in(ctx, cpuctx, EVENT_PINNED, task);
+	cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE, task);
+	if (ctx)
+		ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task);
+}
+
+/*
+ * Cross CPU call to install and enable a performance event
+ *
+ * Must be called with ctx->mutex held
+ */
+static int  __perf_install_in_context(void *info)
+{
+	struct perf_event *event = info;
+	struct perf_event_context *ctx = event->ctx;
+	struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
+	struct perf_event_context *task_ctx = cpuctx->task_ctx;
+	struct task_struct *task = current;
+
+	perf_ctx_lock(cpuctx, task_ctx);
+	perf_pmu_disable(cpuctx->ctx.pmu);
+
+	/*
+	 * If there was an active task_ctx schedule it out.
+	 */
+	if (task_ctx)
+		task_ctx_sched_out(task_ctx);
+
+	/*
+	 * If the context we're installing events in is not the
+	 * active task_ctx, flip them.
+	 */
+	if (ctx->task && task_ctx != ctx) {
+		if (task_ctx)
+			raw_spin_unlock(&task_ctx->lock);
+		raw_spin_lock(&ctx->lock);
+		task_ctx = ctx;
+	}
+
+	if (task_ctx) {
+		cpuctx->task_ctx = task_ctx;
+		task = task_ctx->task;
+	}
+
+	cpu_ctx_sched_out(cpuctx, EVENT_ALL);
+
+	update_context_time(ctx);
+	/*
+	 * update cgrp time only if current cgrp
+	 * matches event->cgrp. Must be done before
+	 * calling add_event_to_ctx()
+	 */
+	update_cgrp_time_from_event(event);
+
+	add_event_to_ctx(event, ctx);
+
+	/*
+	 * Schedule everything back in
+	 */
+	perf_event_sched_in(cpuctx, task_ctx, task);
+
+	perf_pmu_enable(cpuctx->ctx.pmu);
+	perf_ctx_unlock(cpuctx, task_ctx);
+
+	return 0;
+}
+
+/*
+ * Attach a performance event to a context
+ *
+ * First we add the event to the list with the hardware enable bit
+ * in event->hw_config cleared.
+ *
+ * If the event is attached to a task which is on a CPU we use a smp
+ * call to enable it in the task context. The task might have been
+ * scheduled away, but we check this in the smp call again.
+ */
+static void
+perf_install_in_context(struct perf_event_context *ctx,
+			struct perf_event *event,
+			int cpu)
+{
+	struct task_struct *task = ctx->task;
+
+	lockdep_assert_held(&ctx->mutex);
+
+	event->ctx = ctx;
+	if (event->cpu != -1)
+		event->cpu = cpu;
+
+	if (!task) {
+		/*
+		 * Per cpu events are installed via an smp call and
+		 * the install is always successful.
+		 */
+		cpu_function_call(cpu, __perf_install_in_context, event);
+		return;
+	}
+
+retry:
+	if (!task_function_call(task, __perf_install_in_context, event))
+		return;
+
+	raw_spin_lock_irq(&ctx->lock);
+	/*
+	 * If we failed to find a running task, but find the context active now
+	 * that we've acquired the ctx->lock, retry.
+	 */
+	if (ctx->is_active) {
+		raw_spin_unlock_irq(&ctx->lock);
+		/*
+		 * Reload the task pointer, it might have been changed by
+		 * a concurrent perf_event_context_sched_out().
+		 */
+		task = ctx->task;
+		goto retry;
+	}
+
+	/*
+	 * Since the task isn't running, its safe to add the event, us holding
+	 * the ctx->lock ensures the task won't get scheduled in.
+	 */
+	add_event_to_ctx(event, ctx);
+	raw_spin_unlock_irq(&ctx->lock);
+}
+
+/*
+ * Put a event into inactive state and update time fields.
+ * Enabling the leader of a group effectively enables all
+ * the group members that aren't explicitly disabled, so we
+ * have to update their ->tstamp_enabled also.
+ * Note: this works for group members as well as group leaders
+ * since the non-leader members' sibling_lists will be empty.
+ */
+static void __perf_event_mark_enabled(struct perf_event *event)
+{
+	struct perf_event *sub;
+	u64 tstamp = perf_event_time(event);
+
+	event->state = PERF_EVENT_STATE_INACTIVE;
+	event->tstamp_enabled = tstamp - event->total_time_enabled;
+	list_for_each_entry(sub, &event->sibling_list, group_entry) {
+		if (sub->state >= PERF_EVENT_STATE_INACTIVE)
+			sub->tstamp_enabled = tstamp - sub->total_time_enabled;
+	}
+}
+
+/*
+ * Cross CPU call to enable a performance event
+ */
+static int __perf_event_enable(void *info)
+{
+	struct perf_event *event = info;
+	struct perf_event_context *ctx = event->ctx;
+	struct perf_event *leader = event->group_leader;
+	struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
+	int err;
+
+	/*
+	 * There's a time window between 'ctx->is_active' check
+	 * in perf_event_enable function and this place having:
+	 *   - IRQs on
+	 *   - ctx->lock unlocked
+	 *
+	 * where the task could be killed and 'ctx' deactivated
+	 * by perf_event_exit_task.
+	 */
+	if (!ctx->is_active)
+		return -EINVAL;
+
+	raw_spin_lock(&ctx->lock);
+	update_context_time(ctx);
+
+	if (event->state >= PERF_EVENT_STATE_INACTIVE)
+		goto unlock;
+
+	/*
+	 * set current task's cgroup time reference point
+	 */
+	perf_cgroup_set_timestamp(current, ctx);
+
+	__perf_event_mark_enabled(event);
+
+	if (!event_filter_match(event)) {
+		if (is_cgroup_event(event))
+			perf_cgroup_defer_enabled(event);
+		goto unlock;
+	}
+
+	/*
+	 * If the event is in a group and isn't the group leader,
+	 * then don't put it on unless the group is on.
+	 */
+	if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE)
+		goto unlock;
+
+	if (!group_can_go_on(event, cpuctx, 1)) {
+		err = -EEXIST;
+	} else {
+		if (event == leader)
+			err = group_sched_in(event, cpuctx, ctx);
+		else
+			err = event_sched_in(event, cpuctx, ctx);
+	}
+
+	if (err) {
+		/*
+		 * If this event can't go on and it's part of a
+		 * group, then the whole group has to come off.
+		 */
+		if (leader != event) {
+			group_sched_out(leader, cpuctx, ctx);
+			perf_cpu_hrtimer_restart(cpuctx);
+		}
+		if (leader->attr.pinned) {
+			update_group_times(leader);
+			leader->state = PERF_EVENT_STATE_ERROR;
+		}
+	}
+
+unlock:
+	raw_spin_unlock(&ctx->lock);
+
+	return 0;
+}
+
+/*
+ * Enable a event.
+ *
+ * If event->ctx is a cloned context, callers must make sure that
+ * every task struct that event->ctx->task could possibly point to
+ * remains valid.  This condition is satisfied when called through
+ * perf_event_for_each_child or perf_event_for_each as described
+ * for perf_event_disable.
+ */
+void perf_event_enable(struct perf_event *event)
+{
+	struct perf_event_context *ctx = event->ctx;
+	struct task_struct *task = ctx->task;
+
+	if (!task) {
+		/*
+		 * Enable the event on the cpu that it's on
+		 */
+		cpu_function_call(event->cpu, __perf_event_enable, event);
+		return;
+	}
+
+	raw_spin_lock_irq(&ctx->lock);
+	if (event->state >= PERF_EVENT_STATE_INACTIVE)
+		goto out;
+
+	/*
+	 * If the event is in error state, clear that first.
+	 * That way, if we see the event in error state below, we
+	 * know that it has gone back into error state, as distinct
+	 * from the task having been scheduled away before the
+	 * cross-call arrived.
+	 */
+	if (event->state == PERF_EVENT_STATE_ERROR)
+		event->state = PERF_EVENT_STATE_OFF;
+
+retry:
+	if (!ctx->is_active) {
+		__perf_event_mark_enabled(event);
+		goto out;
+	}
+
+	raw_spin_unlock_irq(&ctx->lock);
+
+	if (!task_function_call(task, __perf_event_enable, event))
+		return;
+
+	raw_spin_lock_irq(&ctx->lock);
+
+	/*
+	 * If the context is active and the event is still off,
+	 * we need to retry the cross-call.
+	 */
+	if (ctx->is_active && event->state == PERF_EVENT_STATE_OFF) {
+		/*
+		 * task could have been flipped by a concurrent
+		 * perf_event_context_sched_out()
+		 */
+		task = ctx->task;
+		goto retry;
+	}
+
+out:
+	raw_spin_unlock_irq(&ctx->lock);
+}
+EXPORT_SYMBOL_GPL(perf_event_enable);
+
+int perf_event_refresh(struct perf_event *event, int refresh)
+{
+	/*
+	 * not supported on inherited events
+	 */
+	if (event->attr.inherit || !is_sampling_event(event))
+		return -EINVAL;
+
+	atomic_add(refresh, &event->event_limit);
+	perf_event_enable(event);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(perf_event_refresh);
+
+static void ctx_sched_out(struct perf_event_context *ctx,
+			  struct perf_cpu_context *cpuctx,
+			  enum event_type_t event_type)
+{
+	struct perf_event *event;
+	int is_active = ctx->is_active;
+
+	ctx->is_active &= ~event_type;
+	if (likely(!ctx->nr_events))
+		return;
+
+	update_context_time(ctx);
+	update_cgrp_time_from_cpuctx(cpuctx);
+	if (!ctx->nr_active)
+		return;
+
+	perf_pmu_disable(ctx->pmu);
+	if ((is_active & EVENT_PINNED) && (event_type & EVENT_PINNED)) {
+		list_for_each_entry(event, &ctx->pinned_groups, group_entry)
+			group_sched_out(event, cpuctx, ctx);
+	}
+
+	if ((is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE)) {
+		list_for_each_entry(event, &ctx->flexible_groups, group_entry)
+			group_sched_out(event, cpuctx, ctx);
+	}
+	perf_pmu_enable(ctx->pmu);
+}
+
+/*
+ * Test whether two contexts are equivalent, i.e. whether they have both been
+ * cloned from the same version of the same context.
+ *
+ * Equivalence is measured using a generation number in the context that is
+ * incremented on each modification to it; see unclone_ctx(), list_add_event()
+ * and list_del_event().
+ */
+static int context_equiv(struct perf_event_context *ctx1,
+			 struct perf_event_context *ctx2)
+{
+	lockdep_assert_held(&ctx1->lock);
+	lockdep_assert_held(&ctx2->lock);
+
+	/* Pinning disables the swap optimization */
+	if (ctx1->pin_count || ctx2->pin_count)
+		return 0;
+
+	/* If ctx1 is the parent of ctx2 */
+	if (ctx1 == ctx2->parent_ctx && ctx1->generation == ctx2->parent_gen)
+		return 1;
+
+	/* If ctx2 is the parent of ctx1 */
+	if (ctx1->parent_ctx == ctx2 && ctx1->parent_gen == ctx2->generation)
+		return 1;
+
+	/*
+	 * If ctx1 and ctx2 have the same parent; we flatten the parent
+	 * hierarchy, see perf_event_init_context().
+	 */
+	if (ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx &&
+			ctx1->parent_gen == ctx2->parent_gen)
+		return 1;
+
+	/* Unmatched */
+	return 0;
+}
+
+static void __perf_event_sync_stat(struct perf_event *event,
+				     struct perf_event *next_event)
+{
+	u64 value;
+
+	if (!event->attr.inherit_stat)
+		return;
+
+	/*
+	 * Update the event value, we cannot use perf_event_read()
+	 * because we're in the middle of a context switch and have IRQs
+	 * disabled, which upsets smp_call_function_single(), however
+	 * we know the event must be on the current CPU, therefore we
+	 * don't need to use it.
+	 */
+	switch (event->state) {
+	case PERF_EVENT_STATE_ACTIVE:
+		event->pmu->read(event);
+		/* fall-through */
+
+	case PERF_EVENT_STATE_INACTIVE:
+		update_event_times(event);
+		break;
+
+	default:
+		break;
+	}
+
+	/*
+	 * In order to keep per-task stats reliable we need to flip the event
+	 * values when we flip the contexts.
+	 */
+	value = local64_read(&next_event->count);
+	value = local64_xchg(&event->count, value);
+	local64_set(&next_event->count, value);
+
+	swap(event->total_time_enabled, next_event->total_time_enabled);
+	swap(event->total_time_running, next_event->total_time_running);
+
+	/*
+	 * Since we swizzled the values, update the user visible data too.
+	 */
+	perf_event_update_userpage(event);
+	perf_event_update_userpage(next_event);
+}
+
+static void perf_event_sync_stat(struct perf_event_context *ctx,
+				   struct perf_event_context *next_ctx)
+{
+	struct perf_event *event, *next_event;
+
+	if (!ctx->nr_stat)
+		return;
+
+	update_context_time(ctx);
+
+	event = list_first_entry(&ctx->event_list,
+				   struct perf_event, event_entry);
+
+	next_event = list_first_entry(&next_ctx->event_list,
+					struct perf_event, event_entry);
+
+	while (&event->event_entry != &ctx->event_list &&
+	       &next_event->event_entry != &next_ctx->event_list) {
+
+		__perf_event_sync_stat(event, next_event);
+
+		event = list_next_entry(event, event_entry);
+		next_event = list_next_entry(next_event, event_entry);
+	}
+}
+
+static void perf_event_context_sched_out(struct task_struct *task, int ctxn,
+					 struct task_struct *next)
+{
+	struct perf_event_context *ctx = task->perf_event_ctxp[ctxn];
+	struct perf_event_context *next_ctx;
+	struct perf_event_context *parent, *next_parent;
+	struct perf_cpu_context *cpuctx;
+	int do_switch = 1;
+
+	if (likely(!ctx))
+		return;
+
+	cpuctx = __get_cpu_context(ctx);
+	if (!cpuctx->task_ctx)
+		return;
+
+	rcu_read_lock();
+	next_ctx = next->perf_event_ctxp[ctxn];
+	if (!next_ctx)
+		goto unlock;
+
+	parent = rcu_dereference(ctx->parent_ctx);
+	next_parent = rcu_dereference(next_ctx->parent_ctx);
+
+	/* If neither context have a parent context; they cannot be clones. */
+	if (!parent && !next_parent)
+		goto unlock;
+
+	if (next_parent == ctx || next_ctx == parent || next_parent == parent) {
+		/*
+		 * Looks like the two contexts are clones, so we might be
+		 * able to optimize the context switch.  We lock both
+		 * contexts and check that they are clones under the
+		 * lock (including re-checking that neither has been
+		 * uncloned in the meantime).  It doesn't matter which
+		 * order we take the locks because no other cpu could
+		 * be trying to lock both of these tasks.
+		 */
+		raw_spin_lock(&ctx->lock);
+		raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING);
+		if (context_equiv(ctx, next_ctx)) {
+			/*
+			 * XXX do we need a memory barrier of sorts
+			 * wrt to rcu_dereference() of perf_event_ctxp
+			 */
+			task->perf_event_ctxp[ctxn] = next_ctx;
+			next->perf_event_ctxp[ctxn] = ctx;
+			ctx->task = next;
+			next_ctx->task = task;
+			do_switch = 0;
+
+			perf_event_sync_stat(ctx, next_ctx);
+		}
+		raw_spin_unlock(&next_ctx->lock);
+		raw_spin_unlock(&ctx->lock);
+	}
+unlock:
+	rcu_read_unlock();
+
+	if (do_switch) {
+		raw_spin_lock(&ctx->lock);
+		ctx_sched_out(ctx, cpuctx, EVENT_ALL);
+		cpuctx->task_ctx = NULL;
+		raw_spin_unlock(&ctx->lock);
+	}
+}
+
+#define for_each_task_context_nr(ctxn)					\
+	for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
+
+/*
+ * Called from scheduler to remove the events of the current task,
+ * with interrupts disabled.
+ *
+ * We stop each event and update the event value in event->count.
+ *
+ * This does not protect us against NMI, but disable()
+ * sets the disabled bit in the control field of event _before_
+ * accessing the event control register. If a NMI hits, then it will
+ * not restart the event.
+ */
+void __perf_event_task_sched_out(struct task_struct *task,
+				 struct task_struct *next)
+{
+	int ctxn;
+
+	for_each_task_context_nr(ctxn)
+		perf_event_context_sched_out(task, ctxn, next);
+
+	/*
+	 * if cgroup events exist on this CPU, then we need
+	 * to check if we have to switch out PMU state.
+	 * cgroup event are system-wide mode only
+	 */
+	if (atomic_read(this_cpu_ptr(&perf_cgroup_events)))
+		perf_cgroup_sched_out(task, next);
+}
+
+static void task_ctx_sched_out(struct perf_event_context *ctx)
+{
+	struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
+
+	if (!cpuctx->task_ctx)
+		return;
+
+	if (WARN_ON_ONCE(ctx != cpuctx->task_ctx))
+		return;
+
+	ctx_sched_out(ctx, cpuctx, EVENT_ALL);
+	cpuctx->task_ctx = NULL;
+}
+
+/*
+ * Called with IRQs disabled
+ */
+static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx,
+			      enum event_type_t event_type)
+{
+	ctx_sched_out(&cpuctx->ctx, cpuctx, event_type);
+}
+
+static void
+ctx_pinned_sched_in(struct perf_event_context *ctx,
+		    struct perf_cpu_context *cpuctx)
+{
+	struct perf_event *event;
+
+	list_for_each_entry(event, &ctx->pinned_groups, group_entry) {
+		if (event->state <= PERF_EVENT_STATE_OFF)
+			continue;
+		if (!event_filter_match(event))
+			continue;
+
+		/* may need to reset tstamp_enabled */
+		if (is_cgroup_event(event))
+			perf_cgroup_mark_enabled(event, ctx);
+
+		if (group_can_go_on(event, cpuctx, 1))
+			group_sched_in(event, cpuctx, ctx);
+
+		/*
+		 * If this pinned group hasn't been scheduled,
+		 * put it in error state.
+		 */
+		if (event->state == PERF_EVENT_STATE_INACTIVE) {
+			update_group_times(event);
+			event->state = PERF_EVENT_STATE_ERROR;
+		}
+	}
+}
+
+static void
+ctx_flexible_sched_in(struct perf_event_context *ctx,
+		      struct perf_cpu_context *cpuctx)
+{
+	struct perf_event *event;
+	int can_add_hw = 1;
+
+	list_for_each_entry(event, &ctx->flexible_groups, group_entry) {
+		/* Ignore events in OFF or ERROR state */
+		if (event->state <= PERF_EVENT_STATE_OFF)
+			continue;
+		/*
+		 * Listen to the 'cpu' scheduling filter constraint
+		 * of events:
+		 */
+		if (!event_filter_match(event))
+			continue;
+
+		/* may need to reset tstamp_enabled */
+		if (is_cgroup_event(event))
+			perf_cgroup_mark_enabled(event, ctx);
+
+		if (group_can_go_on(event, cpuctx, can_add_hw)) {
+			if (group_sched_in(event, cpuctx, ctx))
+				can_add_hw = 0;
+		}
+	}
+}
+
+static void
+ctx_sched_in(struct perf_event_context *ctx,
+	     struct perf_cpu_context *cpuctx,
+	     enum event_type_t event_type,
+	     struct task_struct *task)
+{
+	u64 now;
+	int is_active = ctx->is_active;
+
+	ctx->is_active |= event_type;
+	if (likely(!ctx->nr_events))
+		return;
+
+	now = perf_clock();
+	ctx->timestamp = now;
+	perf_cgroup_set_timestamp(task, ctx);
+	/*
+	 * First go through the list and put on any pinned groups
+	 * in order to give them the best chance of going on.
+	 */
+	if (!(is_active & EVENT_PINNED) && (event_type & EVENT_PINNED))
+		ctx_pinned_sched_in(ctx, cpuctx);
+
+	/* Then walk through the lower prio flexible groups */
+	if (!(is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE))
+		ctx_flexible_sched_in(ctx, cpuctx);
+}
+
+static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx,
+			     enum event_type_t event_type,
+			     struct task_struct *task)
+{
+	struct perf_event_context *ctx = &cpuctx->ctx;
+
+	ctx_sched_in(ctx, cpuctx, event_type, task);
+}
+
+static void perf_event_context_sched_in(struct perf_event_context *ctx,
+					struct task_struct *task)
+{
+	struct perf_cpu_context *cpuctx;
+
+	cpuctx = __get_cpu_context(ctx);
+	if (cpuctx->task_ctx == ctx)
+		return;
+
+	perf_ctx_lock(cpuctx, ctx);
+	perf_pmu_disable(ctx->pmu);
+	/*
+	 * We want to keep the following priority order:
+	 * cpu pinned (that don't need to move), task pinned,
+	 * cpu flexible, task flexible.
+	 */
+	cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
+
+	if (ctx->nr_events)
+		cpuctx->task_ctx = ctx;
+
+	perf_event_sched_in(cpuctx, cpuctx->task_ctx, task);
+
+	perf_pmu_enable(ctx->pmu);
+	perf_ctx_unlock(cpuctx, ctx);
+
+	/*
+	 * Since these rotations are per-cpu, we need to ensure the
+	 * cpu-context we got scheduled on is actually rotating.
+	 */
+	perf_pmu_rotate_start(ctx->pmu);
+}
+
+/*
+ * When sampling the branck stack in system-wide, it may be necessary
+ * to flush the stack on context switch. This happens when the branch
+ * stack does not tag its entries with the pid of the current task.
+ * Otherwise it becomes impossible to associate a branch entry with a
+ * task. This ambiguity is more likely to appear when the branch stack
+ * supports priv level filtering and the user sets it to monitor only
+ * at the user level (which could be a useful measurement in system-wide
+ * mode). In that case, the risk is high of having a branch stack with
+ * branch from multiple tasks. Flushing may mean dropping the existing
+ * entries or stashing them somewhere in the PMU specific code layer.
+ *
+ * This function provides the context switch callback to the lower code
+ * layer. It is invoked ONLY when there is at least one system-wide context
+ * with at least one active event using taken branch sampling.
+ */
+static void perf_branch_stack_sched_in(struct task_struct *prev,
+				       struct task_struct *task)
+{
+	struct perf_cpu_context *cpuctx;
+	struct pmu *pmu;
+	unsigned long flags;
+
+	/* no need to flush branch stack if not changing task */
+	if (prev == task)
+		return;
+
+	local_irq_save(flags);
+
+	rcu_read_lock();
+
+	list_for_each_entry_rcu(pmu, &pmus, entry) {
+		cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
+
+		/*
+		 * check if the context has at least one
+		 * event using PERF_SAMPLE_BRANCH_STACK
+		 */
+		if (cpuctx->ctx.nr_branch_stack > 0
+		    && pmu->flush_branch_stack) {
+
+			perf_ctx_lock(cpuctx, cpuctx->task_ctx);
+
+			perf_pmu_disable(pmu);
+
+			pmu->flush_branch_stack();
+
+			perf_pmu_enable(pmu);
+
+			perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
+		}
+	}
+
+	rcu_read_unlock();
+
+	local_irq_restore(flags);
+}
+
+/*
+ * Called from scheduler to add the events of the current task
+ * with interrupts disabled.
+ *
+ * We restore the event value and then enable it.
+ *
+ * This does not protect us against NMI, but enable()
+ * sets the enabled bit in the control field of event _before_
+ * accessing the event control register. If a NMI hits, then it will
+ * keep the event running.
+ */
+void __perf_event_task_sched_in(struct task_struct *prev,
+				struct task_struct *task)
+{
+	struct perf_event_context *ctx;
+	int ctxn;
+
+	for_each_task_context_nr(ctxn) {
+		ctx = task->perf_event_ctxp[ctxn];
+		if (likely(!ctx))
+			continue;
+
+		perf_event_context_sched_in(ctx, task);
+	}
+	/*
+	 * if cgroup events exist on this CPU, then we need
+	 * to check if we have to switch in PMU state.
+	 * cgroup event are system-wide mode only
+	 */
+	if (atomic_read(this_cpu_ptr(&perf_cgroup_events)))
+		perf_cgroup_sched_in(prev, task);
+
+	/* check for system-wide branch_stack events */
+	if (atomic_read(this_cpu_ptr(&perf_branch_stack_events)))
+		perf_branch_stack_sched_in(prev, task);
+}
+
+static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count)
+{
+	u64 frequency = event->attr.sample_freq;
+	u64 sec = NSEC_PER_SEC;
+	u64 divisor, dividend;
+
+	int count_fls, nsec_fls, frequency_fls, sec_fls;
+
+	count_fls = fls64(count);
+	nsec_fls = fls64(nsec);
+	frequency_fls = fls64(frequency);
+	sec_fls = 30;
+
+	/*
+	 * We got @count in @nsec, with a target of sample_freq HZ
+	 * the target period becomes:
+	 *
+	 *             @count * 10^9
+	 * period = -------------------
+	 *          @nsec * sample_freq
+	 *
+	 */
+
+	/*
+	 * Reduce accuracy by one bit such that @a and @b converge
+	 * to a similar magnitude.
+	 */
+#define REDUCE_FLS(a, b)		\
+do {					\
+	if (a##_fls > b##_fls) {	\
+		a >>= 1;		\
+		a##_fls--;		\
+	} else {			\
+		b >>= 1;		\
+		b##_fls--;		\
+	}				\
+} while (0)
+
+	/*
+	 * Reduce accuracy until either term fits in a u64, then proceed with
+	 * the other, so that finally we can do a u64/u64 division.
+	 */
+	while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) {
+		REDUCE_FLS(nsec, frequency);
+		REDUCE_FLS(sec, count);
+	}
+
+	if (count_fls + sec_fls > 64) {
+		divisor = nsec * frequency;
+
+		while (count_fls + sec_fls > 64) {
+			REDUCE_FLS(count, sec);
+			divisor >>= 1;
+		}
+
+		dividend = count * sec;
+	} else {
+		dividend = count * sec;
+
+		while (nsec_fls + frequency_fls > 64) {
+			REDUCE_FLS(nsec, frequency);
+			dividend >>= 1;
+		}
+
+		divisor = nsec * frequency;
+	}
+
+	if (!divisor)
+		return dividend;
+
+	return div64_u64(dividend, divisor);
+}
+
+static DEFINE_PER_CPU(int, perf_throttled_count);
+static DEFINE_PER_CPU(u64, perf_throttled_seq);
+
+static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bool disable)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	s64 period, sample_period;
+	s64 delta;
+
+	period = perf_calculate_period(event, nsec, count);
+
+	delta = (s64)(period - hwc->sample_period);
+	delta = (delta + 7) / 8; /* low pass filter */
+
+	sample_period = hwc->sample_period + delta;
+
+	if (!sample_period)
+		sample_period = 1;
+
+	hwc->sample_period = sample_period;
+
+	if (local64_read(&hwc->period_left) > 8*sample_period) {
+		if (disable)
+			event->pmu->stop(event, PERF_EF_UPDATE);
+
+		local64_set(&hwc->period_left, 0);
+
+		if (disable)
+			event->pmu->start(event, PERF_EF_RELOAD);
+	}
+}
+
+/*
+ * combine freq adjustment with unthrottling to avoid two passes over the
+ * events. At the same time, make sure, having freq events does not change
+ * the rate of unthrottling as that would introduce bias.
+ */
+static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx,
+					   int needs_unthr)
+{
+	struct perf_event *event;
+	struct hw_perf_event *hwc;
+	u64 now, period = TICK_NSEC;
+	s64 delta;
+
+	/*
+	 * only need to iterate over all events iff:
+	 * - context have events in frequency mode (needs freq adjust)
+	 * - there are events to unthrottle on this cpu
+	 */
+	if (!(ctx->nr_freq || needs_unthr))
+		return;
+
+	raw_spin_lock(&ctx->lock);
+	perf_pmu_disable(ctx->pmu);
+
+	list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
+		if (event->state != PERF_EVENT_STATE_ACTIVE)
+			continue;
+
+		if (!event_filter_match(event))
+			continue;
+
+		perf_pmu_disable(event->pmu);
+
+		hwc = &event->hw;
+
+		if (hwc->interrupts == MAX_INTERRUPTS) {
+			hwc->interrupts = 0;
+			perf_log_throttle(event, 1);
+			event->pmu->start(event, 0);
+		}
+
+		if (!event->attr.freq || !event->attr.sample_freq)
+			goto next;
+
+		/*
+		 * stop the event and update event->count
+		 */
+		event->pmu->stop(event, PERF_EF_UPDATE);
+
+		now = local64_read(&event->count);
+		delta = now - hwc->freq_count_stamp;
+		hwc->freq_count_stamp = now;
+
+		/*
+		 * restart the event
+		 * reload only if value has changed
+		 * we have stopped the event so tell that
+		 * to perf_adjust_period() to avoid stopping it
+		 * twice.
+		 */
+		if (delta > 0)
+			perf_adjust_period(event, period, delta, false);
+
+		event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0);
+	next:
+		perf_pmu_enable(event->pmu);
+	}
+
+	perf_pmu_enable(ctx->pmu);
+	raw_spin_unlock(&ctx->lock);
+}
+
+/*
+ * Round-robin a context's events:
+ */
+static void rotate_ctx(struct perf_event_context *ctx)
+{
+	/*
+	 * Rotate the first entry last of non-pinned groups. Rotation might be
+	 * disabled by the inheritance code.
+	 */
+	if (!ctx->rotate_disable)
+		list_rotate_left(&ctx->flexible_groups);
+}
+
+/*
+ * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
+ * because they're strictly cpu affine and rotate_start is called with IRQs
+ * disabled, while rotate_context is called from IRQ context.
+ */
+static int perf_rotate_context(struct perf_cpu_context *cpuctx)
+{
+	struct perf_event_context *ctx = NULL;
+	int rotate = 0, remove = 1;
+
+	if (cpuctx->ctx.nr_events) {
+		remove = 0;
+		if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active)
+			rotate = 1;
+	}
+
+	ctx = cpuctx->task_ctx;
+	if (ctx && ctx->nr_events) {
+		remove = 0;
+		if (ctx->nr_events != ctx->nr_active)
+			rotate = 1;
+	}
+
+	if (!rotate)
+		goto done;
+
+	perf_ctx_lock(cpuctx, cpuctx->task_ctx);
+	perf_pmu_disable(cpuctx->ctx.pmu);
+
+	cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
+	if (ctx)
+		ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE);
+
+	rotate_ctx(&cpuctx->ctx);
+	if (ctx)
+		rotate_ctx(ctx);
+
+	perf_event_sched_in(cpuctx, ctx, current);
+
+	perf_pmu_enable(cpuctx->ctx.pmu);
+	perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
+done:
+	if (remove)
+		list_del_init(&cpuctx->rotation_list);
+
+	return rotate;
+}
+
+#ifdef CONFIG_NO_HZ_FULL
+bool perf_event_can_stop_tick(void)
+{
+	if (atomic_read(&nr_freq_events) ||
+	    __this_cpu_read(perf_throttled_count))
+		return false;
+	else
+		return true;
+}
+#endif
+
+void perf_event_task_tick(void)
+{
+	struct list_head *head = this_cpu_ptr(&rotation_list);
+	struct perf_cpu_context *cpuctx, *tmp;
+	struct perf_event_context *ctx;
+	int throttled;
+
+	WARN_ON(!irqs_disabled());
+
+	__this_cpu_inc(perf_throttled_seq);
+	throttled = __this_cpu_xchg(perf_throttled_count, 0);
+
+	list_for_each_entry_safe(cpuctx, tmp, head, rotation_list) {
+		ctx = &cpuctx->ctx;
+		perf_adjust_freq_unthr_context(ctx, throttled);
+
+		ctx = cpuctx->task_ctx;
+		if (ctx)
+			perf_adjust_freq_unthr_context(ctx, throttled);
+	}
+}
+
+static int event_enable_on_exec(struct perf_event *event,
+				struct perf_event_context *ctx)
+{
+	if (!event->attr.enable_on_exec)
+		return 0;
+
+	event->attr.enable_on_exec = 0;
+	if (event->state >= PERF_EVENT_STATE_INACTIVE)
+		return 0;
+
+	__perf_event_mark_enabled(event);
+
+	return 1;
+}
+
+/*
+ * Enable all of a task's events that have been marked enable-on-exec.
+ * This expects task == current.
+ */
+static void perf_event_enable_on_exec(struct perf_event_context *ctx)
+{
+	struct perf_event_context *clone_ctx = NULL;
+	struct perf_event *event;
+	unsigned long flags;
+	int enabled = 0;
+	int ret;
+
+	local_irq_save(flags);
+	if (!ctx || !ctx->nr_events)
+		goto out;
+
+	/*
+	 * We must ctxsw out cgroup events to avoid conflict
+	 * when invoking perf_task_event_sched_in() later on
+	 * in this function. Otherwise we end up trying to
+	 * ctxswin cgroup events which are already scheduled
+	 * in.
+	 */
+	perf_cgroup_sched_out(current, NULL);
+
+	raw_spin_lock(&ctx->lock);
+	task_ctx_sched_out(ctx);
+
+	list_for_each_entry(event, &ctx->event_list, event_entry) {
+		ret = event_enable_on_exec(event, ctx);
+		if (ret)
+			enabled = 1;
+	}
+
+	/*
+	 * Unclone this context if we enabled any event.
+	 */
+	if (enabled)
+		clone_ctx = unclone_ctx(ctx);
+
+	raw_spin_unlock(&ctx->lock);
+
+	/*
+	 * Also calls ctxswin for cgroup events, if any:
+	 */
+	perf_event_context_sched_in(ctx, ctx->task);
+out:
+	local_irq_restore(flags);
+
+	if (clone_ctx)
+		put_ctx(clone_ctx);
+}
+
+void perf_event_exec(void)
+{
+	struct perf_event_context *ctx;
+	int ctxn;
+
+	rcu_read_lock();
+	for_each_task_context_nr(ctxn) {
+		ctx = current->perf_event_ctxp[ctxn];
+		if (!ctx)
+			continue;
+
+		perf_event_enable_on_exec(ctx);
+	}
+	rcu_read_unlock();
+}
+
+/*
+ * Cross CPU call to read the hardware event
+ */
+static void __perf_event_read(void *info)
+{
+	struct perf_event *event = info;
+	struct perf_event_context *ctx = event->ctx;
+	struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
+
+	/*
+	 * If this is a task context, we need to check whether it is
+	 * the current task context of this cpu.  If not it has been
+	 * scheduled out before the smp call arrived.  In that case
+	 * event->count would have been updated to a recent sample
+	 * when the event was scheduled out.
+	 */
+	if (ctx->task && cpuctx->task_ctx != ctx)
+		return;
+
+	raw_spin_lock(&ctx->lock);
+	if (ctx->is_active) {
+		update_context_time(ctx);
+		update_cgrp_time_from_event(event);
+	}
+	update_event_times(event);
+	if (event->state == PERF_EVENT_STATE_ACTIVE)
+		event->pmu->read(event);
+	raw_spin_unlock(&ctx->lock);
+}
+
+static inline u64 perf_event_count(struct perf_event *event)
+{
+	return local64_read(&event->count) + atomic64_read(&event->child_count);
+}
+
+static u64 perf_event_read(struct perf_event *event)
+{
+	/*
+	 * If event is enabled and currently active on a CPU, update the
+	 * value in the event structure:
+	 */
+	if (event->state == PERF_EVENT_STATE_ACTIVE) {
+		smp_call_function_single(event->oncpu,
+					 __perf_event_read, event, 1);
+	} else if (event->state == PERF_EVENT_STATE_INACTIVE) {
+		struct perf_event_context *ctx = event->ctx;
+		unsigned long flags;
+
+		raw_spin_lock_irqsave(&ctx->lock, flags);
+		/*
+		 * may read while context is not active
+		 * (e.g., thread is blocked), in that case
+		 * we cannot update context time
+		 */
+		if (ctx->is_active) {
+			update_context_time(ctx);
+			update_cgrp_time_from_event(event);
+		}
+		update_event_times(event);
+		raw_spin_unlock_irqrestore(&ctx->lock, flags);
+	}
+
+	return perf_event_count(event);
+}
+
+/*
+ * Initialize the perf_event context in a task_struct:
+ */
+static void __perf_event_init_context(struct perf_event_context *ctx)
+{
+	raw_spin_lock_init(&ctx->lock);
+	mutex_init(&ctx->mutex);
+	INIT_LIST_HEAD(&ctx->pinned_groups);
+	INIT_LIST_HEAD(&ctx->flexible_groups);
+	INIT_LIST_HEAD(&ctx->event_list);
+	atomic_set(&ctx->refcount, 1);
+	INIT_DELAYED_WORK(&ctx->orphans_remove, orphans_remove_work);
+}
+
+static struct perf_event_context *
+alloc_perf_context(struct pmu *pmu, struct task_struct *task)
+{
+	struct perf_event_context *ctx;
+
+	ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL);
+	if (!ctx)
+		return NULL;
+
+	__perf_event_init_context(ctx);
+	if (task) {
+		ctx->task = task;
+		get_task_struct(task);
+	}
+	ctx->pmu = pmu;
+
+	return ctx;
+}
+
+static struct task_struct *
+find_lively_task_by_vpid(pid_t vpid)
+{
+	struct task_struct *task;
+	int err;
+
+	rcu_read_lock();
+	if (!vpid)
+		task = current;
+	else
+		task = find_task_by_vpid(vpid);
+	if (task)
+		get_task_struct(task);
+	rcu_read_unlock();
+
+	if (!task)
+		return ERR_PTR(-ESRCH);
+
+	/* Reuse ptrace permission checks for now. */
+	err = -EACCES;
+	if (!ptrace_may_access(task, PTRACE_MODE_READ))
+		goto errout;
+
+	return task;
+errout:
+	put_task_struct(task);
+	return ERR_PTR(err);
+
+}
+
+/*
+ * Returns a matching context with refcount and pincount.
+ */
+static struct perf_event_context *
+find_get_context(struct pmu *pmu, struct task_struct *task, int cpu)
+{
+	struct perf_event_context *ctx, *clone_ctx = NULL;
+	struct perf_cpu_context *cpuctx;
+	unsigned long flags;
+	int ctxn, err;
+
+	if (!task) {
+		/* Must be root to operate on a CPU event: */
+		if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
+			return ERR_PTR(-EACCES);
+
+		/*
+		 * We could be clever and allow to attach a event to an
+		 * offline CPU and activate it when the CPU comes up, but
+		 * that's for later.
+		 */
+		if (!cpu_online(cpu))
+			return ERR_PTR(-ENODEV);
+
+		cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
+		ctx = &cpuctx->ctx;
+		get_ctx(ctx);
+		++ctx->pin_count;
+
+		return ctx;
+	}
+
+	err = -EINVAL;
+	ctxn = pmu->task_ctx_nr;
+	if (ctxn < 0)
+		goto errout;
+
+retry:
+	ctx = perf_lock_task_context(task, ctxn, &flags);
+	if (ctx) {
+		clone_ctx = unclone_ctx(ctx);
+		++ctx->pin_count;
+		raw_spin_unlock_irqrestore(&ctx->lock, flags);
+
+		if (clone_ctx)
+			put_ctx(clone_ctx);
+	} else {
+		ctx = alloc_perf_context(pmu, task);
+		err = -ENOMEM;
+		if (!ctx)
+			goto errout;
+
+		err = 0;
+		mutex_lock(&task->perf_event_mutex);
+		/*
+		 * If it has already passed perf_event_exit_task().
+		 * we must see PF_EXITING, it takes this mutex too.
+		 */
+		if (task->flags & PF_EXITING)
+			err = -ESRCH;
+		else if (task->perf_event_ctxp[ctxn])
+			err = -EAGAIN;
+		else {
+			get_ctx(ctx);
+			++ctx->pin_count;
+			rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx);
+		}
+		mutex_unlock(&task->perf_event_mutex);
+
+		if (unlikely(err)) {
+			put_ctx(ctx);
+
+			if (err == -EAGAIN)
+				goto retry;
+			goto errout;
+		}
+	}
+
+	return ctx;
+
+errout:
+	return ERR_PTR(err);
+}
+
+static void perf_event_free_filter(struct perf_event *event);
+
+static void free_event_rcu(struct rcu_head *head)
+{
+	struct perf_event *event;
+
+	event = container_of(head, struct perf_event, rcu_head);
+	if (event->ns)
+		put_pid_ns(event->ns);
+	perf_event_free_filter(event);
+	kfree(event);
+}
+
+static void ring_buffer_put(struct ring_buffer *rb);
+static void ring_buffer_attach(struct perf_event *event,
+			       struct ring_buffer *rb);
+
+static void unaccount_event_cpu(struct perf_event *event, int cpu)
+{
+	if (event->parent)
+		return;
+
+	if (has_branch_stack(event)) {
+		if (!(event->attach_state & PERF_ATTACH_TASK))
+			atomic_dec(&per_cpu(perf_branch_stack_events, cpu));
+	}
+	if (is_cgroup_event(event))
+		atomic_dec(&per_cpu(perf_cgroup_events, cpu));
+}
+
+static void unaccount_event(struct perf_event *event)
+{
+	if (event->parent)
+		return;
+
+	if (event->attach_state & PERF_ATTACH_TASK)
+		static_key_slow_dec_deferred(&perf_sched_events);
+	if (event->attr.mmap || event->attr.mmap_data)
+		atomic_dec(&nr_mmap_events);
+	if (event->attr.comm)
+		atomic_dec(&nr_comm_events);
+	if (event->attr.task)
+		atomic_dec(&nr_task_events);
+	if (event->attr.freq)
+		atomic_dec(&nr_freq_events);
+	if (is_cgroup_event(event))
+		static_key_slow_dec_deferred(&perf_sched_events);
+	if (has_branch_stack(event))
+		static_key_slow_dec_deferred(&perf_sched_events);
+
+	unaccount_event_cpu(event, event->cpu);
+}
+
+static void __free_event(struct perf_event *event)
+{
+	if (!event->parent) {
+		if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN)
+			put_callchain_buffers();
+	}
+
+	if (event->destroy)
+		event->destroy(event);
+
+	if (event->ctx)
+		put_ctx(event->ctx);
+
+	if (event->pmu)
+		module_put(event->pmu->module);
+
+	call_rcu(&event->rcu_head, free_event_rcu);
+}
+
+static void _free_event(struct perf_event *event)
+{
+	irq_work_sync(&event->pending);
+
+	unaccount_event(event);
+
+	if (event->rb) {
+		/*
+		 * Can happen when we close an event with re-directed output.
+		 *
+		 * Since we have a 0 refcount, perf_mmap_close() will skip
+		 * over us; possibly making our ring_buffer_put() the last.
+		 */
+		mutex_lock(&event->mmap_mutex);
+		ring_buffer_attach(event, NULL);
+		mutex_unlock(&event->mmap_mutex);
+	}
+
+	if (is_cgroup_event(event))
+		perf_detach_cgroup(event);
+
+	__free_event(event);
+}
+
+/*
+ * Used to free events which have a known refcount of 1, such as in error paths
+ * where the event isn't exposed yet and inherited events.
+ */
+static void free_event(struct perf_event *event)
+{
+	if (WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1,
+				"unexpected event refcount: %ld; ptr=%p\n",
+				atomic_long_read(&event->refcount), event)) {
+		/* leak to avoid use-after-free */
+		return;
+	}
+
+	_free_event(event);
+}
+
+/*
+ * Remove user event from the owner task.
+ */
+static void perf_remove_from_owner(struct perf_event *event)
+{
+	struct task_struct *owner;
+
+	rcu_read_lock();
+	owner = ACCESS_ONCE(event->owner);
+	/*
+	 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
+	 * !owner it means the list deletion is complete and we can indeed
+	 * free this event, otherwise we need to serialize on
+	 * owner->perf_event_mutex.
+	 */
+	smp_read_barrier_depends();
+	if (owner) {
+		/*
+		 * Since delayed_put_task_struct() also drops the last
+		 * task reference we can safely take a new reference
+		 * while holding the rcu_read_lock().
+		 */
+		get_task_struct(owner);
+	}
+	rcu_read_unlock();
+
+	if (owner) {
+		mutex_lock(&owner->perf_event_mutex);
+		/*
+		 * We have to re-check the event->owner field, if it is cleared
+		 * we raced with perf_event_exit_task(), acquiring the mutex
+		 * ensured they're done, and we can proceed with freeing the
+		 * event.
+		 */
+		if (event->owner)
+			list_del_init(&event->owner_entry);
+		mutex_unlock(&owner->perf_event_mutex);
+		put_task_struct(owner);
+	}
+}
+
+/*
+ * Called when the last reference to the file is gone.
+ */
+static void put_event(struct perf_event *event)
+{
+	struct perf_event_context *ctx = event->ctx;
+
+	if (!atomic_long_dec_and_test(&event->refcount))
+		return;
+
+	if (!is_kernel_event(event))
+		perf_remove_from_owner(event);
+
+	WARN_ON_ONCE(ctx->parent_ctx);
+	/*
+	 * There are two ways this annotation is useful:
+	 *
+	 *  1) there is a lock recursion from perf_event_exit_task
+	 *     see the comment there.
+	 *
+	 *  2) there is a lock-inversion with mmap_sem through
+	 *     perf_event_read_group(), which takes faults while
+	 *     holding ctx->mutex, however this is called after
+	 *     the last filedesc died, so there is no possibility
+	 *     to trigger the AB-BA case.
+	 */
+	mutex_lock_nested(&ctx->mutex, SINGLE_DEPTH_NESTING);
+	perf_remove_from_context(event, true);
+	mutex_unlock(&ctx->mutex);
+
+	_free_event(event);
+}
+
+int perf_event_release_kernel(struct perf_event *event)
+{
+	put_event(event);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(perf_event_release_kernel);
+
+static int perf_release(struct inode *inode, struct file *file)
+{
+	put_event(file->private_data);
+	return 0;
+}
+
+/*
+ * Remove all orphanes events from the context.
+ */
+static void orphans_remove_work(struct work_struct *work)
+{
+	struct perf_event_context *ctx;
+	struct perf_event *event, *tmp;
+
+	ctx = container_of(work, struct perf_event_context,
+			   orphans_remove.work);
+
+	mutex_lock(&ctx->mutex);
+	list_for_each_entry_safe(event, tmp, &ctx->event_list, event_entry) {
+		struct perf_event *parent_event = event->parent;
+
+		if (!is_orphaned_child(event))
+			continue;
+
+		perf_remove_from_context(event, true);
+
+		mutex_lock(&parent_event->child_mutex);
+		list_del_init(&event->child_list);
+		mutex_unlock(&parent_event->child_mutex);
+
+		free_event(event);
+		put_event(parent_event);
+	}
+
+	raw_spin_lock_irq(&ctx->lock);
+	ctx->orphans_remove_sched = false;
+	raw_spin_unlock_irq(&ctx->lock);
+	mutex_unlock(&ctx->mutex);
+
+	put_ctx(ctx);
+}
+
+u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running)
+{
+	struct perf_event *child;
+	u64 total = 0;
+
+	*enabled = 0;
+	*running = 0;
+
+	mutex_lock(&event->child_mutex);
+	total += perf_event_read(event);
+	*enabled += event->total_time_enabled +
+			atomic64_read(&event->child_total_time_enabled);
+	*running += event->total_time_running +
+			atomic64_read(&event->child_total_time_running);
+
+	list_for_each_entry(child, &event->child_list, child_list) {
+		total += perf_event_read(child);
+		*enabled += child->total_time_enabled;
+		*running += child->total_time_running;
+	}
+	mutex_unlock(&event->child_mutex);
+
+	return total;
+}
+EXPORT_SYMBOL_GPL(perf_event_read_value);
+
+static int perf_event_read_group(struct perf_event *event,
+				   u64 read_format, char __user *buf)
+{
+	struct perf_event *leader = event->group_leader, *sub;
+	int n = 0, size = 0, ret = -EFAULT;
+	struct perf_event_context *ctx = leader->ctx;
+	u64 values[5];
+	u64 count, enabled, running;
+
+	mutex_lock(&ctx->mutex);
+	count = perf_event_read_value(leader, &enabled, &running);
+
+	values[n++] = 1 + leader->nr_siblings;
+	if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
+		values[n++] = enabled;
+	if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
+		values[n++] = running;
+	values[n++] = count;
+	if (read_format & PERF_FORMAT_ID)
+		values[n++] = primary_event_id(leader);
+
+	size = n * sizeof(u64);
+
+	if (copy_to_user(buf, values, size))
+		goto unlock;
+
+	ret = size;
+
+	list_for_each_entry(sub, &leader->sibling_list, group_entry) {
+		n = 0;
+
+		values[n++] = perf_event_read_value(sub, &enabled, &running);
+		if (read_format & PERF_FORMAT_ID)
+			values[n++] = primary_event_id(sub);
+
+		size = n * sizeof(u64);
+
+		if (copy_to_user(buf + ret, values, size)) {
+			ret = -EFAULT;
+			goto unlock;
+		}
+
+		ret += size;
+	}
+unlock:
+	mutex_unlock(&ctx->mutex);
+
+	return ret;
+}
+
+static int perf_event_read_one(struct perf_event *event,
+				 u64 read_format, char __user *buf)
+{
+	u64 enabled, running;
+	u64 values[4];
+	int n = 0;
+
+	values[n++] = perf_event_read_value(event, &enabled, &running);
+	if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
+		values[n++] = enabled;
+	if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
+		values[n++] = running;
+	if (read_format & PERF_FORMAT_ID)
+		values[n++] = primary_event_id(event);
+
+	if (copy_to_user(buf, values, n * sizeof(u64)))
+		return -EFAULT;
+
+	return n * sizeof(u64);
+}
+
+static bool is_event_hup(struct perf_event *event)
+{
+	bool no_children;
+
+	if (event->state != PERF_EVENT_STATE_EXIT)
+		return false;
+
+	mutex_lock(&event->child_mutex);
+	no_children = list_empty(&event->child_list);
+	mutex_unlock(&event->child_mutex);
+	return no_children;
+}
+
+/*
+ * Read the performance event - simple non blocking version for now
+ */
+static ssize_t
+perf_read_hw(struct perf_event *event, char __user *buf, size_t count)
+{
+	u64 read_format = event->attr.read_format;
+	int ret;
+
+	/*
+	 * Return end-of-file for a read on a event that is in
+	 * error state (i.e. because it was pinned but it couldn't be
+	 * scheduled on to the CPU at some point).
+	 */
+	if (event->state == PERF_EVENT_STATE_ERROR)
+		return 0;
+
+	if (count < event->read_size)
+		return -ENOSPC;
+
+	WARN_ON_ONCE(event->ctx->parent_ctx);
+	if (read_format & PERF_FORMAT_GROUP)
+		ret = perf_event_read_group(event, read_format, buf);
+	else
+		ret = perf_event_read_one(event, read_format, buf);
+
+	return ret;
+}
+
+static ssize_t
+perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
+{
+	struct perf_event *event = file->private_data;
+
+	return perf_read_hw(event, buf, count);
+}
+
+static unsigned int perf_poll(struct file *file, poll_table *wait)
+{
+	struct perf_event *event = file->private_data;
+	struct ring_buffer *rb;
+	unsigned int events = POLLHUP;
+
+	poll_wait(file, &event->waitq, wait);
+
+	if (is_event_hup(event))
+		return events;
+
+	/*
+	 * Pin the event->rb by taking event->mmap_mutex; otherwise
+	 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
+	 */
+	mutex_lock(&event->mmap_mutex);
+	rb = event->rb;
+	if (rb)
+		events = atomic_xchg(&rb->poll, 0);
+	mutex_unlock(&event->mmap_mutex);
+	return events;
+}
+
+static void perf_event_reset(struct perf_event *event)
+{
+	(void)perf_event_read(event);
+	local64_set(&event->count, 0);
+	perf_event_update_userpage(event);
+}
+
+/*
+ * Holding the top-level event's child_mutex means that any
+ * descendant process that has inherited this event will block
+ * in sync_child_event if it goes to exit, thus satisfying the
+ * task existence requirements of perf_event_enable/disable.
+ */
+static void perf_event_for_each_child(struct perf_event *event,
+					void (*func)(struct perf_event *))
+{
+	struct perf_event *child;
+
+	WARN_ON_ONCE(event->ctx->parent_ctx);
+	mutex_lock(&event->child_mutex);
+	func(event);
+	list_for_each_entry(child, &event->child_list, child_list)
+		func(child);
+	mutex_unlock(&event->child_mutex);
+}
+
+static void perf_event_for_each(struct perf_event *event,
+				  void (*func)(struct perf_event *))
+{
+	struct perf_event_context *ctx = event->ctx;
+	struct perf_event *sibling;
+
+	WARN_ON_ONCE(ctx->parent_ctx);
+	mutex_lock(&ctx->mutex);
+	event = event->group_leader;
+
+	perf_event_for_each_child(event, func);
+	list_for_each_entry(sibling, &event->sibling_list, group_entry)
+		perf_event_for_each_child(sibling, func);
+	mutex_unlock(&ctx->mutex);
+}
+
+static int perf_event_period(struct perf_event *event, u64 __user *arg)
+{
+	struct perf_event_context *ctx = event->ctx;
+	int ret = 0, active;
+	u64 value;
+
+	if (!is_sampling_event(event))
+		return -EINVAL;
+
+	if (copy_from_user(&value, arg, sizeof(value)))
+		return -EFAULT;
+
+	if (!value)
+		return -EINVAL;
+
+	raw_spin_lock_irq(&ctx->lock);
+	if (event->attr.freq) {
+		if (value > sysctl_perf_event_sample_rate) {
+			ret = -EINVAL;
+			goto unlock;
+		}
+
+		event->attr.sample_freq = value;
+	} else {
+		event->attr.sample_period = value;
+		event->hw.sample_period = value;
+	}
+
+	active = (event->state == PERF_EVENT_STATE_ACTIVE);
+	if (active) {
+		perf_pmu_disable(ctx->pmu);
+		event->pmu->stop(event, PERF_EF_UPDATE);
+	}
+
+	local64_set(&event->hw.period_left, 0);
+
+	if (active) {
+		event->pmu->start(event, PERF_EF_RELOAD);
+		perf_pmu_enable(ctx->pmu);
+	}
+
+unlock:
+	raw_spin_unlock_irq(&ctx->lock);
+
+	return ret;
+}
+
+static const struct file_operations perf_fops;
+
+static inline int perf_fget_light(int fd, struct fd *p)
+{
+	struct fd f = fdget(fd);
+	if (!f.file)
+		return -EBADF;
+
+	if (f.file->f_op != &perf_fops) {
+		fdput(f);
+		return -EBADF;
+	}
+	*p = f;
+	return 0;
+}
+
+static int perf_event_set_output(struct perf_event *event,
+				 struct perf_event *output_event);
+static int perf_event_set_filter(struct perf_event *event, void __user *arg);
+
+static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct perf_event *event = file->private_data;
+	void (*func)(struct perf_event *);
+	u32 flags = arg;
+
+	switch (cmd) {
+	case PERF_EVENT_IOC_ENABLE:
+		func = perf_event_enable;
+		break;
+	case PERF_EVENT_IOC_DISABLE:
+		func = perf_event_disable;
+		break;
+	case PERF_EVENT_IOC_RESET:
+		func = perf_event_reset;
+		break;
+
+	case PERF_EVENT_IOC_REFRESH:
+		return perf_event_refresh(event, arg);
+
+	case PERF_EVENT_IOC_PERIOD:
+		return perf_event_period(event, (u64 __user *)arg);
+
+	case PERF_EVENT_IOC_ID:
+	{
+		u64 id = primary_event_id(event);
+
+		if (copy_to_user((void __user *)arg, &id, sizeof(id)))
+			return -EFAULT;
+		return 0;
+	}
+
+	case PERF_EVENT_IOC_SET_OUTPUT:
+	{
+		int ret;
+		if (arg != -1) {
+			struct perf_event *output_event;
+			struct fd output;
+			ret = perf_fget_light(arg, &output);
+			if (ret)
+				return ret;
+			output_event = output.file->private_data;
+			ret = perf_event_set_output(event, output_event);
+			fdput(output);
+		} else {
+			ret = perf_event_set_output(event, NULL);
+		}
+		return ret;
+	}
+
+	case PERF_EVENT_IOC_SET_FILTER:
+		return perf_event_set_filter(event, (void __user *)arg);
+
+	default:
+		return -ENOTTY;
+	}
+
+	if (flags & PERF_IOC_FLAG_GROUP)
+		perf_event_for_each(event, func);
+	else
+		perf_event_for_each_child(event, func);
+
+	return 0;
+}
+
+#ifdef CONFIG_COMPAT
+static long perf_compat_ioctl(struct file *file, unsigned int cmd,
+				unsigned long arg)
+{
+	switch (_IOC_NR(cmd)) {
+	case _IOC_NR(PERF_EVENT_IOC_SET_FILTER):
+	case _IOC_NR(PERF_EVENT_IOC_ID):
+		/* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
+		if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) {
+			cmd &= ~IOCSIZE_MASK;
+			cmd |= sizeof(void *) << IOCSIZE_SHIFT;
+		}
+		break;
+	}
+	return perf_ioctl(file, cmd, arg);
+}
+#else
+# define perf_compat_ioctl NULL
+#endif
+
+int perf_event_task_enable(void)
+{
+	struct perf_event *event;
+
+	mutex_lock(&current->perf_event_mutex);
+	list_for_each_entry(event, &current->perf_event_list, owner_entry)
+		perf_event_for_each_child(event, perf_event_enable);
+	mutex_unlock(&current->perf_event_mutex);
+
+	return 0;
+}
+
+int perf_event_task_disable(void)
+{
+	struct perf_event *event;
+
+	mutex_lock(&current->perf_event_mutex);
+	list_for_each_entry(event, &current->perf_event_list, owner_entry)
+		perf_event_for_each_child(event, perf_event_disable);
+	mutex_unlock(&current->perf_event_mutex);
+
+	return 0;
+}
+
+static int perf_event_index(struct perf_event *event)
+{
+	if (event->hw.state & PERF_HES_STOPPED)
+		return 0;
+
+	if (event->state != PERF_EVENT_STATE_ACTIVE)
+		return 0;
+
+	return event->pmu->event_idx(event);
+}
+
+static void calc_timer_values(struct perf_event *event,
+				u64 *now,
+				u64 *enabled,
+				u64 *running)
+{
+	u64 ctx_time;
+
+	*now = perf_clock();
+	ctx_time = event->shadow_ctx_time + *now;
+	*enabled = ctx_time - event->tstamp_enabled;
+	*running = ctx_time - event->tstamp_running;
+}
+
+static void perf_event_init_userpage(struct perf_event *event)
+{
+	struct perf_event_mmap_page *userpg;
+	struct ring_buffer *rb;
+
+	rcu_read_lock();
+	rb = rcu_dereference(event->rb);
+	if (!rb)
+		goto unlock;
+
+	userpg = rb->user_page;
+
+	/* Allow new userspace to detect that bit 0 is deprecated */
+	userpg->cap_bit0_is_deprecated = 1;
+	userpg->size = offsetof(struct perf_event_mmap_page, __reserved);
+
+unlock:
+	rcu_read_unlock();
+}
+
+void __weak arch_perf_update_userpage(struct perf_event_mmap_page *userpg, u64 now)
+{
+}
+
+/*
+ * Callers need to ensure there can be no nesting of this function, otherwise
+ * the seqlock logic goes bad. We can not serialize this because the arch
+ * code calls this from NMI context.
+ */
+void perf_event_update_userpage(struct perf_event *event)
+{
+	struct perf_event_mmap_page *userpg;
+	struct ring_buffer *rb;
+	u64 enabled, running, now;
+
+	rcu_read_lock();
+	rb = rcu_dereference(event->rb);
+	if (!rb)
+		goto unlock;
+
+	/*
+	 * compute total_time_enabled, total_time_running
+	 * based on snapshot values taken when the event
+	 * was last scheduled in.
+	 *
+	 * we cannot simply called update_context_time()
+	 * because of locking issue as we can be called in
+	 * NMI context
+	 */
+	calc_timer_values(event, &now, &enabled, &running);
+
+	userpg = rb->user_page;
+	/*
+	 * Disable preemption so as to not let the corresponding user-space
+	 * spin too long if we get preempted.
+	 */
+	preempt_disable();
+	++userpg->lock;
+	barrier();
+	userpg->index = perf_event_index(event);
+	userpg->offset = perf_event_count(event);
+	if (userpg->index)
+		userpg->offset -= local64_read(&event->hw.prev_count);
+
+	userpg->time_enabled = enabled +
+			atomic64_read(&event->child_total_time_enabled);
+
+	userpg->time_running = running +
+			atomic64_read(&event->child_total_time_running);
+
+	arch_perf_update_userpage(userpg, now);
+
+	barrier();
+	++userpg->lock;
+	preempt_enable();
+unlock:
+	rcu_read_unlock();
+}
+
+static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+	struct perf_event *event = vma->vm_file->private_data;
+	struct ring_buffer *rb;
+	int ret = VM_FAULT_SIGBUS;
+
+	if (vmf->flags & FAULT_FLAG_MKWRITE) {
+		if (vmf->pgoff == 0)
+			ret = 0;
+		return ret;
+	}
+
+	rcu_read_lock();
+	rb = rcu_dereference(event->rb);
+	if (!rb)
+		goto unlock;
+
+	if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE))
+		goto unlock;
+
+	vmf->page = perf_mmap_to_page(rb, vmf->pgoff);
+	if (!vmf->page)
+		goto unlock;
+
+	get_page(vmf->page);
+	vmf->page->mapping = vma->vm_file->f_mapping;
+	vmf->page->index   = vmf->pgoff;
+
+	ret = 0;
+unlock:
+	rcu_read_unlock();
+
+	return ret;
+}
+
+static void ring_buffer_attach(struct perf_event *event,
+			       struct ring_buffer *rb)
+{
+	struct ring_buffer *old_rb = NULL;
+	unsigned long flags;
+
+	if (event->rb) {
+		/*
+		 * Should be impossible, we set this when removing
+		 * event->rb_entry and wait/clear when adding event->rb_entry.
+		 */
+		WARN_ON_ONCE(event->rcu_pending);
+
+		old_rb = event->rb;
+		event->rcu_batches = get_state_synchronize_rcu();
+		event->rcu_pending = 1;
+
+		spin_lock_irqsave(&old_rb->event_lock, flags);
+		list_del_rcu(&event->rb_entry);
+		spin_unlock_irqrestore(&old_rb->event_lock, flags);
+	}
+
+	if (event->rcu_pending && rb) {
+		cond_synchronize_rcu(event->rcu_batches);
+		event->rcu_pending = 0;
+	}
+
+	if (rb) {
+		spin_lock_irqsave(&rb->event_lock, flags);
+		list_add_rcu(&event->rb_entry, &rb->event_list);
+		spin_unlock_irqrestore(&rb->event_lock, flags);
+	}
+
+	rcu_assign_pointer(event->rb, rb);
+
+	if (old_rb) {
+		ring_buffer_put(old_rb);
+		/*
+		 * Since we detached before setting the new rb, so that we
+		 * could attach the new rb, we could have missed a wakeup.
+		 * Provide it now.
+		 */
+		wake_up_all(&event->waitq);
+	}
+}
+
+static void ring_buffer_wakeup(struct perf_event *event)
+{
+	struct ring_buffer *rb;
+
+	rcu_read_lock();
+	rb = rcu_dereference(event->rb);
+	if (rb) {
+		list_for_each_entry_rcu(event, &rb->event_list, rb_entry)
+			wake_up_all(&event->waitq);
+	}
+	rcu_read_unlock();
+}
+
+static void rb_free_rcu(struct rcu_head *rcu_head)
+{
+	struct ring_buffer *rb;
+
+	rb = container_of(rcu_head, struct ring_buffer, rcu_head);
+	rb_free(rb);
+}
+
+static struct ring_buffer *ring_buffer_get(struct perf_event *event)
+{
+	struct ring_buffer *rb;
+
+	rcu_read_lock();
+	rb = rcu_dereference(event->rb);
+	if (rb) {
+		if (!atomic_inc_not_zero(&rb->refcount))
+			rb = NULL;
+	}
+	rcu_read_unlock();
+
+	return rb;
+}
+
+static void ring_buffer_put(struct ring_buffer *rb)
+{
+	if (!atomic_dec_and_test(&rb->refcount))
+		return;
+
+	WARN_ON_ONCE(!list_empty(&rb->event_list));
+
+	call_rcu(&rb->rcu_head, rb_free_rcu);
+}
+
+static void perf_mmap_open(struct vm_area_struct *vma)
+{
+	struct perf_event *event = vma->vm_file->private_data;
+
+	atomic_inc(&event->mmap_count);
+	atomic_inc(&event->rb->mmap_count);
+}
+
+/*
+ * A buffer can be mmap()ed multiple times; either directly through the same
+ * event, or through other events by use of perf_event_set_output().
+ *
+ * In order to undo the VM accounting done by perf_mmap() we need to destroy
+ * the buffer here, where we still have a VM context. This means we need
+ * to detach all events redirecting to us.
+ */
+static void perf_mmap_close(struct vm_area_struct *vma)
+{
+	struct perf_event *event = vma->vm_file->private_data;
+
+	struct ring_buffer *rb = ring_buffer_get(event);
+	struct user_struct *mmap_user = rb->mmap_user;
+	int mmap_locked = rb->mmap_locked;
+	unsigned long size = perf_data_size(rb);
+
+	atomic_dec(&rb->mmap_count);
+
+	if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex))
+		goto out_put;
+
+	ring_buffer_attach(event, NULL);
+	mutex_unlock(&event->mmap_mutex);
+
+	/* If there's still other mmap()s of this buffer, we're done. */
+	if (atomic_read(&rb->mmap_count))
+		goto out_put;
+
+	/*
+	 * No other mmap()s, detach from all other events that might redirect
+	 * into the now unreachable buffer. Somewhat complicated by the
+	 * fact that rb::event_lock otherwise nests inside mmap_mutex.
+	 */
+again:
+	rcu_read_lock();
+	list_for_each_entry_rcu(event, &rb->event_list, rb_entry) {
+		if (!atomic_long_inc_not_zero(&event->refcount)) {
+			/*
+			 * This event is en-route to free_event() which will
+			 * detach it and remove it from the list.
+			 */
+			continue;
+		}
+		rcu_read_unlock();
+
+		mutex_lock(&event->mmap_mutex);
+		/*
+		 * Check we didn't race with perf_event_set_output() which can
+		 * swizzle the rb from under us while we were waiting to
+		 * acquire mmap_mutex.
+		 *
+		 * If we find a different rb; ignore this event, a next
+		 * iteration will no longer find it on the list. We have to
+		 * still restart the iteration to make sure we're not now
+		 * iterating the wrong list.
+		 */
+		if (event->rb == rb)
+			ring_buffer_attach(event, NULL);
+
+		mutex_unlock(&event->mmap_mutex);
+		put_event(event);
+
+		/*
+		 * Restart the iteration; either we're on the wrong list or
+		 * destroyed its integrity by doing a deletion.
+		 */
+		goto again;
+	}
+	rcu_read_unlock();
+
+	/*
+	 * It could be there's still a few 0-ref events on the list; they'll
+	 * get cleaned up by free_event() -- they'll also still have their
+	 * ref on the rb and will free it whenever they are done with it.
+	 *
+	 * Aside from that, this buffer is 'fully' detached and unmapped,
+	 * undo the VM accounting.
+	 */
+
+	atomic_long_sub((size >> PAGE_SHIFT) + 1, &mmap_user->locked_vm);
+	vma->vm_mm->pinned_vm -= mmap_locked;
+	free_uid(mmap_user);
+
+out_put:
+	ring_buffer_put(rb); /* could be last */
+}
+
+static const struct vm_operations_struct perf_mmap_vmops = {
+	.open		= perf_mmap_open,
+	.close		= perf_mmap_close,
+	.fault		= perf_mmap_fault,
+	.page_mkwrite	= perf_mmap_fault,
+};
+
+static int perf_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct perf_event *event = file->private_data;
+	unsigned long user_locked, user_lock_limit;
+	struct user_struct *user = current_user();
+	unsigned long locked, lock_limit;
+	struct ring_buffer *rb;
+	unsigned long vma_size;
+	unsigned long nr_pages;
+	long user_extra, extra;
+	int ret = 0, flags = 0;
+
+	/*
+	 * Don't allow mmap() of inherited per-task counters. This would
+	 * create a performance issue due to all children writing to the
+	 * same rb.
+	 */
+	if (event->cpu == -1 && event->attr.inherit)
+		return -EINVAL;
+
+	if (!(vma->vm_flags & VM_SHARED))
+		return -EINVAL;
+
+	vma_size = vma->vm_end - vma->vm_start;
+	nr_pages = (vma_size / PAGE_SIZE) - 1;
+
+	/*
+	 * If we have rb pages ensure they're a power-of-two number, so we
+	 * can do bitmasks instead of modulo.
+	 */
+	if (nr_pages != 0 && !is_power_of_2(nr_pages))
+		return -EINVAL;
+
+	if (vma_size != PAGE_SIZE * (1 + nr_pages))
+		return -EINVAL;
+
+	if (vma->vm_pgoff != 0)
+		return -EINVAL;
+
+	WARN_ON_ONCE(event->ctx->parent_ctx);
+again:
+	mutex_lock(&event->mmap_mutex);
+	if (event->rb) {
+		if (event->rb->nr_pages != nr_pages) {
+			ret = -EINVAL;
+			goto unlock;
+		}
+
+		if (!atomic_inc_not_zero(&event->rb->mmap_count)) {
+			/*
+			 * Raced against perf_mmap_close() through
+			 * perf_event_set_output(). Try again, hope for better
+			 * luck.
+			 */
+			mutex_unlock(&event->mmap_mutex);
+			goto again;
+		}
+
+		goto unlock;
+	}
+
+	user_extra = nr_pages + 1;
+	user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10);
+
+	/*
+	 * Increase the limit linearly with more CPUs:
+	 */
+	user_lock_limit *= num_online_cpus();
+
+	user_locked = atomic_long_read(&user->locked_vm) + user_extra;
+
+	extra = 0;
+	if (user_locked > user_lock_limit)
+		extra = user_locked - user_lock_limit;
+
+	lock_limit = rlimit(RLIMIT_MEMLOCK);
+	lock_limit >>= PAGE_SHIFT;
+	locked = vma->vm_mm->pinned_vm + extra;
+
+	if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() &&
+		!capable(CAP_IPC_LOCK)) {
+		ret = -EPERM;
+		goto unlock;
+	}
+
+	WARN_ON(event->rb);
+
+	if (vma->vm_flags & VM_WRITE)
+		flags |= RING_BUFFER_WRITABLE;
+
+	rb = rb_alloc(nr_pages, 
+		event->attr.watermark ? event->attr.wakeup_watermark : 0,
+		event->cpu, flags);
+
+	if (!rb) {
+		ret = -ENOMEM;
+		goto unlock;
+	}
+
+	atomic_set(&rb->mmap_count, 1);
+	rb->mmap_locked = extra;
+	rb->mmap_user = get_current_user();
+
+	atomic_long_add(user_extra, &user->locked_vm);
+	vma->vm_mm->pinned_vm += extra;
+
+	ring_buffer_attach(event, rb);
+
+	perf_event_init_userpage(event);
+	perf_event_update_userpage(event);
+
+unlock:
+	if (!ret)
+		atomic_inc(&event->mmap_count);
+	mutex_unlock(&event->mmap_mutex);
+
+	/*
+	 * Since pinned accounting is per vm we cannot allow fork() to copy our
+	 * vma.
+	 */
+	vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP;
+	vma->vm_ops = &perf_mmap_vmops;
+
+	return ret;
+}
+
+static int perf_fasync(int fd, struct file *filp, int on)
+{
+	struct inode *inode = file_inode(filp);
+	struct perf_event *event = filp->private_data;
+	int retval;
+
+	mutex_lock(&inode->i_mutex);
+	retval = fasync_helper(fd, filp, on, &event->fasync);
+	mutex_unlock(&inode->i_mutex);
+
+	if (retval < 0)
+		return retval;
+
+	return 0;
+}
+
+static const struct file_operations perf_fops = {
+	.llseek			= no_llseek,
+	.release		= perf_release,
+	.read			= perf_read,
+	.poll			= perf_poll,
+	.unlocked_ioctl		= perf_ioctl,
+	.compat_ioctl		= perf_compat_ioctl,
+	.mmap			= perf_mmap,
+	.fasync			= perf_fasync,
+};
+
+/*
+ * Perf event wakeup
+ *
+ * If there's data, ensure we set the poll() state and publish everything
+ * to user-space before waking everybody up.
+ */
+
+void perf_event_wakeup(struct perf_event *event)
+{
+	ring_buffer_wakeup(event);
+
+	if (event->pending_kill) {
+		kill_fasync(&event->fasync, SIGIO, event->pending_kill);
+		event->pending_kill = 0;
+	}
+}
+
+static void perf_pending_event(struct irq_work *entry)
+{
+	struct perf_event *event = container_of(entry,
+			struct perf_event, pending);
+	int rctx;
+
+	rctx = perf_swevent_get_recursion_context();
+	/*
+	 * If we 'fail' here, that's OK, it means recursion is already disabled
+	 * and we won't recurse 'further'.
+	 */
+
+	if (event->pending_disable) {
+		event->pending_disable = 0;
+		__perf_event_disable(event);
+	}
+
+	if (event->pending_wakeup) {
+		event->pending_wakeup = 0;
+		perf_event_wakeup(event);
+	}
+
+	if (rctx >= 0)
+		perf_swevent_put_recursion_context(rctx);
+}
+
+/*
+ * We assume there is only KVM supporting the callbacks.
+ * Later on, we might change it to a list if there is
+ * another virtualization implementation supporting the callbacks.
+ */
+struct perf_guest_info_callbacks *perf_guest_cbs;
+
+int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
+{
+	perf_guest_cbs = cbs;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks);
+
+int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
+{
+	perf_guest_cbs = NULL;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks);
+
+static void
+perf_output_sample_regs(struct perf_output_handle *handle,
+			struct pt_regs *regs, u64 mask)
+{
+	int bit;
+
+	for_each_set_bit(bit, (const unsigned long *) &mask,
+			 sizeof(mask) * BITS_PER_BYTE) {
+		u64 val;
+
+		val = perf_reg_value(regs, bit);
+		perf_output_put(handle, val);
+	}
+}
+
+static void perf_sample_regs_user(struct perf_regs_user *regs_user,
+				  struct pt_regs *regs)
+{
+	if (!user_mode(regs)) {
+		if (current->mm)
+			regs = task_pt_regs(current);
+		else
+			regs = NULL;
+	}
+
+	if (regs) {
+		regs_user->regs = regs;
+		regs_user->abi  = perf_reg_abi(current);
+	}
+}
+
+/*
+ * Get remaining task size from user stack pointer.
+ *
+ * It'd be better to take stack vma map and limit this more
+ * precisly, but there's no way to get it safely under interrupt,
+ * so using TASK_SIZE as limit.
+ */
+static u64 perf_ustack_task_size(struct pt_regs *regs)
+{
+	unsigned long addr = perf_user_stack_pointer(regs);
+
+	if (!addr || addr >= TASK_SIZE)
+		return 0;
+
+	return TASK_SIZE - addr;
+}
+
+static u16
+perf_sample_ustack_size(u16 stack_size, u16 header_size,
+			struct pt_regs *regs)
+{
+	u64 task_size;
+
+	/* No regs, no stack pointer, no dump. */
+	if (!regs)
+		return 0;
+
+	/*
+	 * Check if we fit in with the requested stack size into the:
+	 * - TASK_SIZE
+	 *   If we don't, we limit the size to the TASK_SIZE.
+	 *
+	 * - remaining sample size
+	 *   If we don't, we customize the stack size to
+	 *   fit in to the remaining sample size.
+	 */
+
+	task_size  = min((u64) USHRT_MAX, perf_ustack_task_size(regs));
+	stack_size = min(stack_size, (u16) task_size);
+
+	/* Current header size plus static size and dynamic size. */
+	header_size += 2 * sizeof(u64);
+
+	/* Do we fit in with the current stack dump size? */
+	if ((u16) (header_size + stack_size) < header_size) {
+		/*
+		 * If we overflow the maximum size for the sample,
+		 * we customize the stack dump size to fit in.
+		 */
+		stack_size = USHRT_MAX - header_size - sizeof(u64);
+		stack_size = round_up(stack_size, sizeof(u64));
+	}
+
+	return stack_size;
+}
+
+static void
+perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size,
+			  struct pt_regs *regs)
+{
+	/* Case of a kernel thread, nothing to dump */
+	if (!regs) {
+		u64 size = 0;
+		perf_output_put(handle, size);
+	} else {
+		unsigned long sp;
+		unsigned int rem;
+		u64 dyn_size;
+
+		/*
+		 * We dump:
+		 * static size
+		 *   - the size requested by user or the best one we can fit
+		 *     in to the sample max size
+		 * data
+		 *   - user stack dump data
+		 * dynamic size
+		 *   - the actual dumped size
+		 */
+
+		/* Static size. */
+		perf_output_put(handle, dump_size);
+
+		/* Data. */
+		sp = perf_user_stack_pointer(regs);
+		rem = __output_copy_user(handle, (void *) sp, dump_size);
+		dyn_size = dump_size - rem;
+
+		perf_output_skip(handle, rem);
+
+		/* Dynamic size. */
+		perf_output_put(handle, dyn_size);
+	}
+}
+
+static void __perf_event_header__init_id(struct perf_event_header *header,
+					 struct perf_sample_data *data,
+					 struct perf_event *event)
+{
+	u64 sample_type = event->attr.sample_type;
+
+	data->type = sample_type;
+	header->size += event->id_header_size;
+
+	if (sample_type & PERF_SAMPLE_TID) {
+		/* namespace issues */
+		data->tid_entry.pid = perf_event_pid(event, current);
+		data->tid_entry.tid = perf_event_tid(event, current);
+	}
+
+	if (sample_type & PERF_SAMPLE_TIME)
+		data->time = perf_clock();
+
+	if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER))
+		data->id = primary_event_id(event);
+
+	if (sample_type & PERF_SAMPLE_STREAM_ID)
+		data->stream_id = event->id;
+
+	if (sample_type & PERF_SAMPLE_CPU) {
+		data->cpu_entry.cpu	 = raw_smp_processor_id();
+		data->cpu_entry.reserved = 0;
+	}
+}
+
+void perf_event_header__init_id(struct perf_event_header *header,
+				struct perf_sample_data *data,
+				struct perf_event *event)
+{
+	if (event->attr.sample_id_all)
+		__perf_event_header__init_id(header, data, event);
+}
+
+static void __perf_event__output_id_sample(struct perf_output_handle *handle,
+					   struct perf_sample_data *data)
+{
+	u64 sample_type = data->type;
+
+	if (sample_type & PERF_SAMPLE_TID)
+		perf_output_put(handle, data->tid_entry);
+
+	if (sample_type & PERF_SAMPLE_TIME)
+		perf_output_put(handle, data->time);
+
+	if (sample_type & PERF_SAMPLE_ID)
+		perf_output_put(handle, data->id);
+
+	if (sample_type & PERF_SAMPLE_STREAM_ID)
+		perf_output_put(handle, data->stream_id);
+
+	if (sample_type & PERF_SAMPLE_CPU)
+		perf_output_put(handle, data->cpu_entry);
+
+	if (sample_type & PERF_SAMPLE_IDENTIFIER)
+		perf_output_put(handle, data->id);
+}
+
+void perf_event__output_id_sample(struct perf_event *event,
+				  struct perf_output_handle *handle,
+				  struct perf_sample_data *sample)
+{
+	if (event->attr.sample_id_all)
+		__perf_event__output_id_sample(handle, sample);
+}
+
+static void perf_output_read_one(struct perf_output_handle *handle,
+				 struct perf_event *event,
+				 u64 enabled, u64 running)
+{
+	u64 read_format = event->attr.read_format;
+	u64 values[4];
+	int n = 0;
+
+	values[n++] = perf_event_count(event);
+	if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
+		values[n++] = enabled +
+			atomic64_read(&event->child_total_time_enabled);
+	}
+	if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
+		values[n++] = running +
+			atomic64_read(&event->child_total_time_running);
+	}
+	if (read_format & PERF_FORMAT_ID)
+		values[n++] = primary_event_id(event);
+
+	__output_copy(handle, values, n * sizeof(u64));
+}
+
+/*
+ * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
+ */
+static void perf_output_read_group(struct perf_output_handle *handle,
+			    struct perf_event *event,
+			    u64 enabled, u64 running)
+{
+	struct perf_event *leader = event->group_leader, *sub;
+	u64 read_format = event->attr.read_format;
+	u64 values[5];
+	int n = 0;
+
+	values[n++] = 1 + leader->nr_siblings;
+
+	if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
+		values[n++] = enabled;
+
+	if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
+		values[n++] = running;
+
+	if (leader != event)
+		leader->pmu->read(leader);
+
+	values[n++] = perf_event_count(leader);
+	if (read_format & PERF_FORMAT_ID)
+		values[n++] = primary_event_id(leader);
+
+	__output_copy(handle, values, n * sizeof(u64));
+
+	list_for_each_entry(sub, &leader->sibling_list, group_entry) {
+		n = 0;
+
+		if ((sub != event) &&
+		    (sub->state == PERF_EVENT_STATE_ACTIVE))
+			sub->pmu->read(sub);
+
+		values[n++] = perf_event_count(sub);
+		if (read_format & PERF_FORMAT_ID)
+			values[n++] = primary_event_id(sub);
+
+		__output_copy(handle, values, n * sizeof(u64));
+	}
+}
+
+#define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
+				 PERF_FORMAT_TOTAL_TIME_RUNNING)
+
+static void perf_output_read(struct perf_output_handle *handle,
+			     struct perf_event *event)
+{
+	u64 enabled = 0, running = 0, now;
+	u64 read_format = event->attr.read_format;
+
+	/*
+	 * compute total_time_enabled, total_time_running
+	 * based on snapshot values taken when the event
+	 * was last scheduled in.
+	 *
+	 * we cannot simply called update_context_time()
+	 * because of locking issue as we are called in
+	 * NMI context
+	 */
+	if (read_format & PERF_FORMAT_TOTAL_TIMES)
+		calc_timer_values(event, &now, &enabled, &running);
+
+	if (event->attr.read_format & PERF_FORMAT_GROUP)
+		perf_output_read_group(handle, event, enabled, running);
+	else
+		perf_output_read_one(handle, event, enabled, running);
+}
+
+void perf_output_sample(struct perf_output_handle *handle,
+			struct perf_event_header *header,
+			struct perf_sample_data *data,
+			struct perf_event *event)
+{
+	u64 sample_type = data->type;
+
+	perf_output_put(handle, *header);
+
+	if (sample_type & PERF_SAMPLE_IDENTIFIER)
+		perf_output_put(handle, data->id);
+
+	if (sample_type & PERF_SAMPLE_IP)
+		perf_output_put(handle, data->ip);
+
+	if (sample_type & PERF_SAMPLE_TID)
+		perf_output_put(handle, data->tid_entry);
+
+	if (sample_type & PERF_SAMPLE_TIME)
+		perf_output_put(handle, data->time);
+
+	if (sample_type & PERF_SAMPLE_ADDR)
+		perf_output_put(handle, data->addr);
+
+	if (sample_type & PERF_SAMPLE_ID)
+		perf_output_put(handle, data->id);
+
+	if (sample_type & PERF_SAMPLE_STREAM_ID)
+		perf_output_put(handle, data->stream_id);
+
+	if (sample_type & PERF_SAMPLE_CPU)
+		perf_output_put(handle, data->cpu_entry);
+
+	if (sample_type & PERF_SAMPLE_PERIOD)
+		perf_output_put(handle, data->period);
+
+	if (sample_type & PERF_SAMPLE_READ)
+		perf_output_read(handle, event);
+
+	if (sample_type & PERF_SAMPLE_CALLCHAIN) {
+		if (data->callchain) {
+			int size = 1;
+
+			if (data->callchain)
+				size += data->callchain->nr;
+
+			size *= sizeof(u64);
+
+			__output_copy(handle, data->callchain, size);
+		} else {
+			u64 nr = 0;
+			perf_output_put(handle, nr);
+		}
+	}
+
+	if (sample_type & PERF_SAMPLE_RAW) {
+		if (data->raw) {
+			perf_output_put(handle, data->raw->size);
+			__output_copy(handle, data->raw->data,
+					   data->raw->size);
+		} else {
+			struct {
+				u32	size;
+				u32	data;
+			} raw = {
+				.size = sizeof(u32),
+				.data = 0,
+			};
+			perf_output_put(handle, raw);
+		}
+	}
+
+	if (sample_type & PERF_SAMPLE_BRANCH_STACK) {
+		if (data->br_stack) {
+			size_t size;
+
+			size = data->br_stack->nr
+			     * sizeof(struct perf_branch_entry);
+
+			perf_output_put(handle, data->br_stack->nr);
+			perf_output_copy(handle, data->br_stack->entries, size);
+		} else {
+			/*
+			 * we always store at least the value of nr
+			 */
+			u64 nr = 0;
+			perf_output_put(handle, nr);
+		}
+	}
+
+	if (sample_type & PERF_SAMPLE_REGS_USER) {
+		u64 abi = data->regs_user.abi;
+
+		/*
+		 * If there are no regs to dump, notice it through
+		 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
+		 */
+		perf_output_put(handle, abi);
+
+		if (abi) {
+			u64 mask = event->attr.sample_regs_user;
+			perf_output_sample_regs(handle,
+						data->regs_user.regs,
+						mask);
+		}
+	}
+
+	if (sample_type & PERF_SAMPLE_STACK_USER) {
+		perf_output_sample_ustack(handle,
+					  data->stack_user_size,
+					  data->regs_user.regs);
+	}
+
+	if (sample_type & PERF_SAMPLE_WEIGHT)
+		perf_output_put(handle, data->weight);
+
+	if (sample_type & PERF_SAMPLE_DATA_SRC)
+		perf_output_put(handle, data->data_src.val);
+
+	if (sample_type & PERF_SAMPLE_TRANSACTION)
+		perf_output_put(handle, data->txn);
+
+	if (!event->attr.watermark) {
+		int wakeup_events = event->attr.wakeup_events;
+
+		if (wakeup_events) {
+			struct ring_buffer *rb = handle->rb;
+			int events = local_inc_return(&rb->events);
+
+			if (events >= wakeup_events) {
+				local_sub(wakeup_events, &rb->events);
+				local_inc(&rb->wakeup);
+			}
+		}
+	}
+}
+
+void perf_prepare_sample(struct perf_event_header *header,
+			 struct perf_sample_data *data,
+			 struct perf_event *event,
+			 struct pt_regs *regs)
+{
+	u64 sample_type = event->attr.sample_type;
+
+	header->type = PERF_RECORD_SAMPLE;
+	header->size = sizeof(*header) + event->header_size;
+
+	header->misc = 0;
+	header->misc |= perf_misc_flags(regs);
+
+	__perf_event_header__init_id(header, data, event);
+
+	if (sample_type & PERF_SAMPLE_IP)
+		data->ip = perf_instruction_pointer(regs);
+
+	if (sample_type & PERF_SAMPLE_CALLCHAIN) {
+		int size = 1;
+
+		data->callchain = perf_callchain(event, regs);
+
+		if (data->callchain)
+			size += data->callchain->nr;
+
+		header->size += size * sizeof(u64);
+	}
+
+	if (sample_type & PERF_SAMPLE_RAW) {
+		int size = sizeof(u32);
+
+		if (data->raw)
+			size += data->raw->size;
+		else
+			size += sizeof(u32);
+
+		WARN_ON_ONCE(size & (sizeof(u64)-1));
+		header->size += size;
+	}
+
+	if (sample_type & PERF_SAMPLE_BRANCH_STACK) {
+		int size = sizeof(u64); /* nr */
+		if (data->br_stack) {
+			size += data->br_stack->nr
+			      * sizeof(struct perf_branch_entry);
+		}
+		header->size += size;
+	}
+
+	if (sample_type & PERF_SAMPLE_REGS_USER) {
+		/* regs dump ABI info */
+		int size = sizeof(u64);
+
+		perf_sample_regs_user(&data->regs_user, regs);
+
+		if (data->regs_user.regs) {
+			u64 mask = event->attr.sample_regs_user;
+			size += hweight64(mask) * sizeof(u64);
+		}
+
+		header->size += size;
+	}
+
+	if (sample_type & PERF_SAMPLE_STACK_USER) {
+		/*
+		 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
+		 * processed as the last one or have additional check added
+		 * in case new sample type is added, because we could eat
+		 * up the rest of the sample size.
+		 */
+		struct perf_regs_user *uregs = &data->regs_user;
+		u16 stack_size = event->attr.sample_stack_user;
+		u16 size = sizeof(u64);
+
+		if (!uregs->abi)
+			perf_sample_regs_user(uregs, regs);
+
+		stack_size = perf_sample_ustack_size(stack_size, header->size,
+						     uregs->regs);
+
+		/*
+		 * If there is something to dump, add space for the dump
+		 * itself and for the field that tells the dynamic size,
+		 * which is how many have been actually dumped.
+		 */
+		if (stack_size)
+			size += sizeof(u64) + stack_size;
+
+		data->stack_user_size = stack_size;
+		header->size += size;
+	}
+}
+
+static void perf_event_output(struct perf_event *event,
+				struct perf_sample_data *data,
+				struct pt_regs *regs)
+{
+	struct perf_output_handle handle;
+	struct perf_event_header header;
+
+	/* protect the callchain buffers */
+	rcu_read_lock();
+
+	perf_prepare_sample(&header, data, event, regs);
+
+	if (perf_output_begin(&handle, event, header.size))
+		goto exit;
+
+	perf_output_sample(&handle, &header, data, event);
+
+	perf_output_end(&handle);
+
+exit:
+	rcu_read_unlock();
+}
+
+/*
+ * read event_id
+ */
+
+struct perf_read_event {
+	struct perf_event_header	header;
+
+	u32				pid;
+	u32				tid;
+};
+
+static void
+perf_event_read_event(struct perf_event *event,
+			struct task_struct *task)
+{
+	struct perf_output_handle handle;
+	struct perf_sample_data sample;
+	struct perf_read_event read_event = {
+		.header = {
+			.type = PERF_RECORD_READ,
+			.misc = 0,
+			.size = sizeof(read_event) + event->read_size,
+		},
+		.pid = perf_event_pid(event, task),
+		.tid = perf_event_tid(event, task),
+	};
+	int ret;
+
+	perf_event_header__init_id(&read_event.header, &sample, event);
+	ret = perf_output_begin(&handle, event, read_event.header.size);
+	if (ret)
+		return;
+
+	perf_output_put(&handle, read_event);
+	perf_output_read(&handle, event);
+	perf_event__output_id_sample(event, &handle, &sample);
+
+	perf_output_end(&handle);
+}
+
+typedef void (perf_event_aux_output_cb)(struct perf_event *event, void *data);
+
+static void
+perf_event_aux_ctx(struct perf_event_context *ctx,
+		   perf_event_aux_output_cb output,
+		   void *data)
+{
+	struct perf_event *event;
+
+	list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
+		if (event->state < PERF_EVENT_STATE_INACTIVE)
+			continue;
+		if (!event_filter_match(event))
+			continue;
+		output(event, data);
+	}
+}
+
+static void
+perf_event_aux(perf_event_aux_output_cb output, void *data,
+	       struct perf_event_context *task_ctx)
+{
+	struct perf_cpu_context *cpuctx;
+	struct perf_event_context *ctx;
+	struct pmu *pmu;
+	int ctxn;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(pmu, &pmus, entry) {
+		cpuctx = get_cpu_ptr(pmu->pmu_cpu_context);
+		if (cpuctx->unique_pmu != pmu)
+			goto next;
+		perf_event_aux_ctx(&cpuctx->ctx, output, data);
+		if (task_ctx)
+			goto next;
+		ctxn = pmu->task_ctx_nr;
+		if (ctxn < 0)
+			goto next;
+		ctx = rcu_dereference(current->perf_event_ctxp[ctxn]);
+		if (ctx)
+			perf_event_aux_ctx(ctx, output, data);
+next:
+		put_cpu_ptr(pmu->pmu_cpu_context);
+	}
+
+	if (task_ctx) {
+		preempt_disable();
+		perf_event_aux_ctx(task_ctx, output, data);
+		preempt_enable();
+	}
+	rcu_read_unlock();
+}
+
+/*
+ * task tracking -- fork/exit
+ *
+ * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
+ */
+
+struct perf_task_event {
+	struct task_struct		*task;
+	struct perf_event_context	*task_ctx;
+
+	struct {
+		struct perf_event_header	header;
+
+		u32				pid;
+		u32				ppid;
+		u32				tid;
+		u32				ptid;
+		u64				time;
+	} event_id;
+};
+
+static int perf_event_task_match(struct perf_event *event)
+{
+	return event->attr.comm  || event->attr.mmap ||
+	       event->attr.mmap2 || event->attr.mmap_data ||
+	       event->attr.task;
+}
+
+static void perf_event_task_output(struct perf_event *event,
+				   void *data)
+{
+	struct perf_task_event *task_event = data;
+	struct perf_output_handle handle;
+	struct perf_sample_data	sample;
+	struct task_struct *task = task_event->task;
+	int ret, size = task_event->event_id.header.size;
+
+	if (!perf_event_task_match(event))
+		return;
+
+	perf_event_header__init_id(&task_event->event_id.header, &sample, event);
+
+	ret = perf_output_begin(&handle, event,
+				task_event->event_id.header.size);
+	if (ret)
+		goto out;
+
+	task_event->event_id.pid = perf_event_pid(event, task);
+	task_event->event_id.ppid = perf_event_pid(event, current);
+
+	task_event->event_id.tid = perf_event_tid(event, task);
+	task_event->event_id.ptid = perf_event_tid(event, current);
+
+	perf_output_put(&handle, task_event->event_id);
+
+	perf_event__output_id_sample(event, &handle, &sample);
+
+	perf_output_end(&handle);
+out:
+	task_event->event_id.header.size = size;
+}
+
+static void perf_event_task(struct task_struct *task,
+			      struct perf_event_context *task_ctx,
+			      int new)
+{
+	struct perf_task_event task_event;
+
+	if (!atomic_read(&nr_comm_events) &&
+	    !atomic_read(&nr_mmap_events) &&
+	    !atomic_read(&nr_task_events))
+		return;
+
+	task_event = (struct perf_task_event){
+		.task	  = task,
+		.task_ctx = task_ctx,
+		.event_id    = {
+			.header = {
+				.type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT,
+				.misc = 0,
+				.size = sizeof(task_event.event_id),
+			},
+			/* .pid  */
+			/* .ppid */
+			/* .tid  */
+			/* .ptid */
+			.time = perf_clock(),
+		},
+	};
+
+	perf_event_aux(perf_event_task_output,
+		       &task_event,
+		       task_ctx);
+}
+
+void perf_event_fork(struct task_struct *task)
+{
+	perf_event_task(task, NULL, 1);
+}
+
+/*
+ * comm tracking
+ */
+
+struct perf_comm_event {
+	struct task_struct	*task;
+	char			*comm;
+	int			comm_size;
+
+	struct {
+		struct perf_event_header	header;
+
+		u32				pid;
+		u32				tid;
+	} event_id;
+};
+
+static int perf_event_comm_match(struct perf_event *event)
+{
+	return event->attr.comm;
+}
+
+static void perf_event_comm_output(struct perf_event *event,
+				   void *data)
+{
+	struct perf_comm_event *comm_event = data;
+	struct perf_output_handle handle;
+	struct perf_sample_data sample;
+	int size = comm_event->event_id.header.size;
+	int ret;
+
+	if (!perf_event_comm_match(event))
+		return;
+
+	perf_event_header__init_id(&comm_event->event_id.header, &sample, event);
+	ret = perf_output_begin(&handle, event,
+				comm_event->event_id.header.size);
+
+	if (ret)
+		goto out;
+
+	comm_event->event_id.pid = perf_event_pid(event, comm_event->task);
+	comm_event->event_id.tid = perf_event_tid(event, comm_event->task);
+
+	perf_output_put(&handle, comm_event->event_id);
+	__output_copy(&handle, comm_event->comm,
+				   comm_event->comm_size);
+
+	perf_event__output_id_sample(event, &handle, &sample);
+
+	perf_output_end(&handle);
+out:
+	comm_event->event_id.header.size = size;
+}
+
+static void perf_event_comm_event(struct perf_comm_event *comm_event)
+{
+	char comm[TASK_COMM_LEN];
+	unsigned int size;
+
+	memset(comm, 0, sizeof(comm));
+	strlcpy(comm, comm_event->task->comm, sizeof(comm));
+	size = ALIGN(strlen(comm)+1, sizeof(u64));
+
+	comm_event->comm = comm;
+	comm_event->comm_size = size;
+
+	comm_event->event_id.header.size = sizeof(comm_event->event_id) + size;
+
+	perf_event_aux(perf_event_comm_output,
+		       comm_event,
+		       NULL);
+}
+
+void perf_event_comm(struct task_struct *task, bool exec)
+{
+	struct perf_comm_event comm_event;
+
+	if (!atomic_read(&nr_comm_events))
+		return;
+
+	comm_event = (struct perf_comm_event){
+		.task	= task,
+		/* .comm      */
+		/* .comm_size */
+		.event_id  = {
+			.header = {
+				.type = PERF_RECORD_COMM,
+				.misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0,
+				/* .size */
+			},
+			/* .pid */
+			/* .tid */
+		},
+	};
+
+	perf_event_comm_event(&comm_event);
+}
+
+/*
+ * mmap tracking
+ */
+
+struct perf_mmap_event {
+	struct vm_area_struct	*vma;
+
+	const char		*file_name;
+	int			file_size;
+	int			maj, min;
+	u64			ino;
+	u64			ino_generation;
+	u32			prot, flags;
+
+	struct {
+		struct perf_event_header	header;
+
+		u32				pid;
+		u32				tid;
+		u64				start;
+		u64				len;
+		u64				pgoff;
+	} event_id;
+};
+
+static int perf_event_mmap_match(struct perf_event *event,
+				 void *data)
+{
+	struct perf_mmap_event *mmap_event = data;
+	struct vm_area_struct *vma = mmap_event->vma;
+	int executable = vma->vm_flags & VM_EXEC;
+
+	return (!executable && event->attr.mmap_data) ||
+	       (executable && (event->attr.mmap || event->attr.mmap2));
+}
+
+static void perf_event_mmap_output(struct perf_event *event,
+				   void *data)
+{
+	struct perf_mmap_event *mmap_event = data;
+	struct perf_output_handle handle;
+	struct perf_sample_data sample;
+	int size = mmap_event->event_id.header.size;
+	int ret;
+
+	if (!perf_event_mmap_match(event, data))
+		return;
+
+	if (event->attr.mmap2) {
+		mmap_event->event_id.header.type = PERF_RECORD_MMAP2;
+		mmap_event->event_id.header.size += sizeof(mmap_event->maj);
+		mmap_event->event_id.header.size += sizeof(mmap_event->min);
+		mmap_event->event_id.header.size += sizeof(mmap_event->ino);
+		mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation);
+		mmap_event->event_id.header.size += sizeof(mmap_event->prot);
+		mmap_event->event_id.header.size += sizeof(mmap_event->flags);
+	}
+
+	perf_event_header__init_id(&mmap_event->event_id.header, &sample, event);
+	ret = perf_output_begin(&handle, event,
+				mmap_event->event_id.header.size);
+	if (ret)
+		goto out;
+
+	mmap_event->event_id.pid = perf_event_pid(event, current);
+	mmap_event->event_id.tid = perf_event_tid(event, current);
+
+	perf_output_put(&handle, mmap_event->event_id);
+
+	if (event->attr.mmap2) {
+		perf_output_put(&handle, mmap_event->maj);
+		perf_output_put(&handle, mmap_event->min);
+		perf_output_put(&handle, mmap_event->ino);
+		perf_output_put(&handle, mmap_event->ino_generation);
+		perf_output_put(&handle, mmap_event->prot);
+		perf_output_put(&handle, mmap_event->flags);
+	}
+
+	__output_copy(&handle, mmap_event->file_name,
+				   mmap_event->file_size);
+
+	perf_event__output_id_sample(event, &handle, &sample);
+
+	perf_output_end(&handle);
+out:
+	mmap_event->event_id.header.size = size;
+}
+
+static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
+{
+	struct vm_area_struct *vma = mmap_event->vma;
+	struct file *file = vma->vm_file;
+	int maj = 0, min = 0;
+	u64 ino = 0, gen = 0;
+	u32 prot = 0, flags = 0;
+	unsigned int size;
+	char tmp[16];
+	char *buf = NULL;
+	char *name;
+
+	if (file) {
+		struct inode *inode;
+		dev_t dev;
+
+		buf = kmalloc(PATH_MAX, GFP_KERNEL);
+		if (!buf) {
+			name = "//enomem";
+			goto cpy_name;
+		}
+		/*
+		 * d_path() works from the end of the rb backwards, so we
+		 * need to add enough zero bytes after the string to handle
+		 * the 64bit alignment we do later.
+		 */
+		name = d_path(&file->f_path, buf, PATH_MAX - sizeof(u64));
+		if (IS_ERR(name)) {
+			name = "//toolong";
+			goto cpy_name;
+		}
+		inode = file_inode(vma->vm_file);
+		dev = inode->i_sb->s_dev;
+		ino = inode->i_ino;
+		gen = inode->i_generation;
+		maj = MAJOR(dev);
+		min = MINOR(dev);
+
+		if (vma->vm_flags & VM_READ)
+			prot |= PROT_READ;
+		if (vma->vm_flags & VM_WRITE)
+			prot |= PROT_WRITE;
+		if (vma->vm_flags & VM_EXEC)
+			prot |= PROT_EXEC;
+
+		if (vma->vm_flags & VM_MAYSHARE)
+			flags = MAP_SHARED;
+		else
+			flags = MAP_PRIVATE;
+
+		if (vma->vm_flags & VM_DENYWRITE)
+			flags |= MAP_DENYWRITE;
+		if (vma->vm_flags & VM_MAYEXEC)
+			flags |= MAP_EXECUTABLE;
+		if (vma->vm_flags & VM_LOCKED)
+			flags |= MAP_LOCKED;
+		if (vma->vm_flags & VM_HUGETLB)
+			flags |= MAP_HUGETLB;
+
+		goto got_name;
+	} else {
+		if (vma->vm_ops && vma->vm_ops->name) {
+			name = (char *) vma->vm_ops->name(vma);
+			if (name)
+				goto cpy_name;
+		}
+
+		name = (char *)arch_vma_name(vma);
+		if (name)
+			goto cpy_name;
+
+		if (vma->vm_start <= vma->vm_mm->start_brk &&
+				vma->vm_end >= vma->vm_mm->brk) {
+			name = "[heap]";
+			goto cpy_name;
+		}
+		if (vma->vm_start <= vma->vm_mm->start_stack &&
+				vma->vm_end >= vma->vm_mm->start_stack) {
+			name = "[stack]";
+			goto cpy_name;
+		}
+
+		name = "//anon";
+		goto cpy_name;
+	}
+
+cpy_name:
+	strlcpy(tmp, name, sizeof(tmp));
+	name = tmp;
+got_name:
+	/*
+	 * Since our buffer works in 8 byte units we need to align our string
+	 * size to a multiple of 8. However, we must guarantee the tail end is
+	 * zero'd out to avoid leaking random bits to userspace.
+	 */
+	size = strlen(name)+1;
+	while (!IS_ALIGNED(size, sizeof(u64)))
+		name[size++] = '\0';
+
+	mmap_event->file_name = name;
+	mmap_event->file_size = size;
+	mmap_event->maj = maj;
+	mmap_event->min = min;
+	mmap_event->ino = ino;
+	mmap_event->ino_generation = gen;
+	mmap_event->prot = prot;
+	mmap_event->flags = flags;
+
+	if (!(vma->vm_flags & VM_EXEC))
+		mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA;
+
+	mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size;
+
+	perf_event_aux(perf_event_mmap_output,
+		       mmap_event,
+		       NULL);
+
+	kfree(buf);
+}
+
+void perf_event_mmap(struct vm_area_struct *vma)
+{
+	struct perf_mmap_event mmap_event;
+
+	if (!atomic_read(&nr_mmap_events))
+		return;
+
+	mmap_event = (struct perf_mmap_event){
+		.vma	= vma,
+		/* .file_name */
+		/* .file_size */
+		.event_id  = {
+			.header = {
+				.type = PERF_RECORD_MMAP,
+				.misc = PERF_RECORD_MISC_USER,
+				/* .size */
+			},
+			/* .pid */
+			/* .tid */
+			.start  = vma->vm_start,
+			.len    = vma->vm_end - vma->vm_start,
+			.pgoff  = (u64)vma->vm_pgoff << PAGE_SHIFT,
+		},
+		/* .maj (attr_mmap2 only) */
+		/* .min (attr_mmap2 only) */
+		/* .ino (attr_mmap2 only) */
+		/* .ino_generation (attr_mmap2 only) */
+		/* .prot (attr_mmap2 only) */
+		/* .flags (attr_mmap2 only) */
+	};
+
+	perf_event_mmap_event(&mmap_event);
+}
+
+/*
+ * IRQ throttle logging
+ */
+
+static void perf_log_throttle(struct perf_event *event, int enable)
+{
+	struct perf_output_handle handle;
+	struct perf_sample_data sample;
+	int ret;
+
+	struct {
+		struct perf_event_header	header;
+		u64				time;
+		u64				id;
+		u64				stream_id;
+	} throttle_event = {
+		.header = {
+			.type = PERF_RECORD_THROTTLE,
+			.misc = 0,
+			.size = sizeof(throttle_event),
+		},
+		.time		= perf_clock(),
+		.id		= primary_event_id(event),
+		.stream_id	= event->id,
+	};
+
+	if (enable)
+		throttle_event.header.type = PERF_RECORD_UNTHROTTLE;
+
+	perf_event_header__init_id(&throttle_event.header, &sample, event);
+
+	ret = perf_output_begin(&handle, event,
+				throttle_event.header.size);
+	if (ret)
+		return;
+
+	perf_output_put(&handle, throttle_event);
+	perf_event__output_id_sample(event, &handle, &sample);
+	perf_output_end(&handle);
+}
+
+/*
+ * Generic event overflow handling, sampling.
+ */
+
+static int __perf_event_overflow(struct perf_event *event,
+				   int throttle, struct perf_sample_data *data,
+				   struct pt_regs *regs)
+{
+	int events = atomic_read(&event->event_limit);
+	struct hw_perf_event *hwc = &event->hw;
+	u64 seq;
+	int ret = 0;
+
+	/*
+	 * Non-sampling counters might still use the PMI to fold short
+	 * hardware counters, ignore those.
+	 */
+	if (unlikely(!is_sampling_event(event)))
+		return 0;
+
+	seq = __this_cpu_read(perf_throttled_seq);
+	if (seq != hwc->interrupts_seq) {
+		hwc->interrupts_seq = seq;
+		hwc->interrupts = 1;
+	} else {
+		hwc->interrupts++;
+		if (unlikely(throttle
+			     && hwc->interrupts >= max_samples_per_tick)) {
+			__this_cpu_inc(perf_throttled_count);
+			hwc->interrupts = MAX_INTERRUPTS;
+			perf_log_throttle(event, 0);
+			tick_nohz_full_kick();
+			ret = 1;
+		}
+	}
+
+	if (event->attr.freq) {
+		u64 now = perf_clock();
+		s64 delta = now - hwc->freq_time_stamp;
+
+		hwc->freq_time_stamp = now;
+
+		if (delta > 0 && delta < 2*TICK_NSEC)
+			perf_adjust_period(event, delta, hwc->last_period, true);
+	}
+
+	/*
+	 * XXX event_limit might not quite work as expected on inherited
+	 * events
+	 */
+
+	event->pending_kill = POLL_IN;
+	if (events && atomic_dec_and_test(&event->event_limit)) {
+		ret = 1;
+		event->pending_kill = POLL_HUP;
+		event->pending_disable = 1;
+		irq_work_queue(&event->pending);
+	}
+
+	if (event->overflow_handler)
+		event->overflow_handler(event, data, regs);
+	else
+		perf_event_output(event, data, regs);
+
+	if (event->fasync && event->pending_kill) {
+		event->pending_wakeup = 1;
+		irq_work_queue(&event->pending);
+	}
+
+	return ret;
+}
+
+int perf_event_overflow(struct perf_event *event,
+			  struct perf_sample_data *data,
+			  struct pt_regs *regs)
+{
+	return __perf_event_overflow(event, 1, data, regs);
+}
+
+/*
+ * Generic software event infrastructure
+ */
+
+struct swevent_htable {
+	struct swevent_hlist		*swevent_hlist;
+	struct mutex			hlist_mutex;
+	int				hlist_refcount;
+
+	/* Recursion avoidance in each contexts */
+	int				recursion[PERF_NR_CONTEXTS];
+
+	/* Keeps track of cpu being initialized/exited */
+	bool				online;
+};
+
+static DEFINE_PER_CPU(struct swevent_htable, swevent_htable);
+
+/*
+ * We directly increment event->count and keep a second value in
+ * event->hw.period_left to count intervals. This period event
+ * is kept in the range [-sample_period, 0] so that we can use the
+ * sign as trigger.
+ */
+
+u64 perf_swevent_set_period(struct perf_event *event)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	u64 period = hwc->last_period;
+	u64 nr, offset;
+	s64 old, val;
+
+	hwc->last_period = hwc->sample_period;
+
+again:
+	old = val = local64_read(&hwc->period_left);
+	if (val < 0)
+		return 0;
+
+	nr = div64_u64(period + val, period);
+	offset = nr * period;
+	val -= offset;
+	if (local64_cmpxchg(&hwc->period_left, old, val) != old)
+		goto again;
+
+	return nr;
+}
+
+static void perf_swevent_overflow(struct perf_event *event, u64 overflow,
+				    struct perf_sample_data *data,
+				    struct pt_regs *regs)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	int throttle = 0;
+
+	if (!overflow)
+		overflow = perf_swevent_set_period(event);
+
+	if (hwc->interrupts == MAX_INTERRUPTS)
+		return;
+
+	for (; overflow; overflow--) {
+		if (__perf_event_overflow(event, throttle,
+					    data, regs)) {
+			/*
+			 * We inhibit the overflow from happening when
+			 * hwc->interrupts == MAX_INTERRUPTS.
+			 */
+			break;
+		}
+		throttle = 1;
+	}
+}
+
+static void perf_swevent_event(struct perf_event *event, u64 nr,
+			       struct perf_sample_data *data,
+			       struct pt_regs *regs)
+{
+	struct hw_perf_event *hwc = &event->hw;
+
+	local64_add(nr, &event->count);
+
+	if (!regs)
+		return;
+
+	if (!is_sampling_event(event))
+		return;
+
+	if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) {
+		data->period = nr;
+		return perf_swevent_overflow(event, 1, data, regs);
+	} else
+		data->period = event->hw.last_period;
+
+	if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq)
+		return perf_swevent_overflow(event, 1, data, regs);
+
+	if (local64_add_negative(nr, &hwc->period_left))
+		return;
+
+	perf_swevent_overflow(event, 0, data, regs);
+}
+
+static int perf_exclude_event(struct perf_event *event,
+			      struct pt_regs *regs)
+{
+	if (event->hw.state & PERF_HES_STOPPED)
+		return 1;
+
+	if (regs) {
+		if (event->attr.exclude_user && user_mode(regs))
+			return 1;
+
+		if (event->attr.exclude_kernel && !user_mode(regs))
+			return 1;
+	}
+
+	return 0;
+}
+
+static int perf_swevent_match(struct perf_event *event,
+				enum perf_type_id type,
+				u32 event_id,
+				struct perf_sample_data *data,
+				struct pt_regs *regs)
+{
+	if (event->attr.type != type)
+		return 0;
+
+	if (event->attr.config != event_id)
+		return 0;
+
+	if (perf_exclude_event(event, regs))
+		return 0;
+
+	return 1;
+}
+
+static inline u64 swevent_hash(u64 type, u32 event_id)
+{
+	u64 val = event_id | (type << 32);
+
+	return hash_64(val, SWEVENT_HLIST_BITS);
+}
+
+static inline struct hlist_head *
+__find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id)
+{
+	u64 hash = swevent_hash(type, event_id);
+
+	return &hlist->heads[hash];
+}
+
+/* For the read side: events when they trigger */
+static inline struct hlist_head *
+find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id)
+{
+	struct swevent_hlist *hlist;
+
+	hlist = rcu_dereference(swhash->swevent_hlist);
+	if (!hlist)
+		return NULL;
+
+	return __find_swevent_head(hlist, type, event_id);
+}
+
+/* For the event head insertion and removal in the hlist */
+static inline struct hlist_head *
+find_swevent_head(struct swevent_htable *swhash, struct perf_event *event)
+{
+	struct swevent_hlist *hlist;
+	u32 event_id = event->attr.config;
+	u64 type = event->attr.type;
+
+	/*
+	 * Event scheduling is always serialized against hlist allocation
+	 * and release. Which makes the protected version suitable here.
+	 * The context lock guarantees that.
+	 */
+	hlist = rcu_dereference_protected(swhash->swevent_hlist,
+					  lockdep_is_held(&event->ctx->lock));
+	if (!hlist)
+		return NULL;
+
+	return __find_swevent_head(hlist, type, event_id);
+}
+
+static void do_perf_sw_event(enum perf_type_id type, u32 event_id,
+				    u64 nr,
+				    struct perf_sample_data *data,
+				    struct pt_regs *regs)
+{
+	struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
+	struct perf_event *event;
+	struct hlist_head *head;
+
+	rcu_read_lock();
+	head = find_swevent_head_rcu(swhash, type, event_id);
+	if (!head)
+		goto end;
+
+	hlist_for_each_entry_rcu(event, head, hlist_entry) {
+		if (perf_swevent_match(event, type, event_id, data, regs))
+			perf_swevent_event(event, nr, data, regs);
+	}
+end:
+	rcu_read_unlock();
+}
+
+int perf_swevent_get_recursion_context(void)
+{
+	struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
+
+	return get_recursion_context(swhash->recursion);
+}
+EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context);
+
+inline void perf_swevent_put_recursion_context(int rctx)
+{
+	struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
+
+	put_recursion_context(swhash->recursion, rctx);
+}
+
+void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
+{
+	struct perf_sample_data data;
+	int rctx;
+
+	preempt_disable_notrace();
+	rctx = perf_swevent_get_recursion_context();
+	if (rctx < 0)
+		return;
+
+	perf_sample_data_init(&data, addr, 0);
+
+	do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs);
+
+	perf_swevent_put_recursion_context(rctx);
+	preempt_enable_notrace();
+}
+
+static void perf_swevent_read(struct perf_event *event)
+{
+}
+
+static int perf_swevent_add(struct perf_event *event, int flags)
+{
+	struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
+	struct hw_perf_event *hwc = &event->hw;
+	struct hlist_head *head;
+
+	if (is_sampling_event(event)) {
+		hwc->last_period = hwc->sample_period;
+		perf_swevent_set_period(event);
+	}
+
+	hwc->state = !(flags & PERF_EF_START);
+
+	head = find_swevent_head(swhash, event);
+	if (!head) {
+		/*
+		 * We can race with cpu hotplug code. Do not
+		 * WARN if the cpu just got unplugged.
+		 */
+		WARN_ON_ONCE(swhash->online);
+		return -EINVAL;
+	}
+
+	hlist_add_head_rcu(&event->hlist_entry, head);
+
+	return 0;
+}
+
+static void perf_swevent_del(struct perf_event *event, int flags)
+{
+	hlist_del_rcu(&event->hlist_entry);
+}
+
+static void perf_swevent_start(struct perf_event *event, int flags)
+{
+	event->hw.state = 0;
+}
+
+static void perf_swevent_stop(struct perf_event *event, int flags)
+{
+	event->hw.state = PERF_HES_STOPPED;
+}
+
+/* Deref the hlist from the update side */
+static inline struct swevent_hlist *
+swevent_hlist_deref(struct swevent_htable *swhash)
+{
+	return rcu_dereference_protected(swhash->swevent_hlist,
+					 lockdep_is_held(&swhash->hlist_mutex));
+}
+
+static void swevent_hlist_release(struct swevent_htable *swhash)
+{
+	struct swevent_hlist *hlist = swevent_hlist_deref(swhash);
+
+	if (!hlist)
+		return;
+
+	RCU_INIT_POINTER(swhash->swevent_hlist, NULL);
+	kfree_rcu(hlist, rcu_head);
+}
+
+static void swevent_hlist_put_cpu(struct perf_event *event, int cpu)
+{
+	struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
+
+	mutex_lock(&swhash->hlist_mutex);
+
+	if (!--swhash->hlist_refcount)
+		swevent_hlist_release(swhash);
+
+	mutex_unlock(&swhash->hlist_mutex);
+}
+
+static void swevent_hlist_put(struct perf_event *event)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu)
+		swevent_hlist_put_cpu(event, cpu);
+}
+
+static int swevent_hlist_get_cpu(struct perf_event *event, int cpu)
+{
+	struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
+	int err = 0;
+
+	mutex_lock(&swhash->hlist_mutex);
+
+	if (!swevent_hlist_deref(swhash) && cpu_online(cpu)) {
+		struct swevent_hlist *hlist;
+
+		hlist = kzalloc(sizeof(*hlist), GFP_KERNEL);
+		if (!hlist) {
+			err = -ENOMEM;
+			goto exit;
+		}
+		rcu_assign_pointer(swhash->swevent_hlist, hlist);
+	}
+	swhash->hlist_refcount++;
+exit:
+	mutex_unlock(&swhash->hlist_mutex);
+
+	return err;
+}
+
+static int swevent_hlist_get(struct perf_event *event)
+{
+	int err;
+	int cpu, failed_cpu;
+
+	get_online_cpus();
+	for_each_possible_cpu(cpu) {
+		err = swevent_hlist_get_cpu(event, cpu);
+		if (err) {
+			failed_cpu = cpu;
+			goto fail;
+		}
+	}
+	put_online_cpus();
+
+	return 0;
+fail:
+	for_each_possible_cpu(cpu) {
+		if (cpu == failed_cpu)
+			break;
+		swevent_hlist_put_cpu(event, cpu);
+	}
+
+	put_online_cpus();
+	return err;
+}
+
+struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX];
+
+static void sw_perf_event_destroy(struct perf_event *event)
+{
+	u64 event_id = event->attr.config;
+
+	WARN_ON(event->parent);
+
+	static_key_slow_dec(&perf_swevent_enabled[event_id]);
+	swevent_hlist_put(event);
+}
+
+static int perf_swevent_init(struct perf_event *event)
+{
+	u64 event_id = event->attr.config;
+
+	if (event->attr.type != PERF_TYPE_SOFTWARE)
+		return -ENOENT;
+
+	/*
+	 * no branch sampling for software events
+	 */
+	if (has_branch_stack(event))
+		return -EOPNOTSUPP;
+
+	switch (event_id) {
+	case PERF_COUNT_SW_CPU_CLOCK:
+	case PERF_COUNT_SW_TASK_CLOCK:
+		return -ENOENT;
+
+	default:
+		break;
+	}
+
+	if (event_id >= PERF_COUNT_SW_MAX)
+		return -ENOENT;
+
+	if (!event->parent) {
+		int err;
+
+		err = swevent_hlist_get(event);
+		if (err)
+			return err;
+
+		static_key_slow_inc(&perf_swevent_enabled[event_id]);
+		event->destroy = sw_perf_event_destroy;
+	}
+
+	return 0;
+}
+
+static struct pmu perf_swevent = {
+	.task_ctx_nr	= perf_sw_context,
+
+	.event_init	= perf_swevent_init,
+	.add		= perf_swevent_add,
+	.del		= perf_swevent_del,
+	.start		= perf_swevent_start,
+	.stop		= perf_swevent_stop,
+	.read		= perf_swevent_read,
+};
+
+#ifdef CONFIG_EVENT_TRACING
+
+static int perf_tp_filter_match(struct perf_event *event,
+				struct perf_sample_data *data)
+{
+	void *record = data->raw->data;
+
+	if (likely(!event->filter) || filter_match_preds(event->filter, record))
+		return 1;
+	return 0;
+}
+
+static int perf_tp_event_match(struct perf_event *event,
+				struct perf_sample_data *data,
+				struct pt_regs *regs)
+{
+	if (event->hw.state & PERF_HES_STOPPED)
+		return 0;
+	/*
+	 * All tracepoints are from kernel-space.
+	 */
+	if (event->attr.exclude_kernel)
+		return 0;
+
+	if (!perf_tp_filter_match(event, data))
+		return 0;
+
+	return 1;
+}
+
+void perf_tp_event(u64 addr, u64 count, void *record, int entry_size,
+		   struct pt_regs *regs, struct hlist_head *head, int rctx,
+		   struct task_struct *task)
+{
+	struct perf_sample_data data;
+	struct perf_event *event;
+
+	struct perf_raw_record raw = {
+		.size = entry_size,
+		.data = record,
+	};
+
+	perf_sample_data_init(&data, addr, 0);
+	data.raw = &raw;
+
+	hlist_for_each_entry_rcu(event, head, hlist_entry) {
+		if (perf_tp_event_match(event, &data, regs))
+			perf_swevent_event(event, count, &data, regs);
+	}
+
+	/*
+	 * If we got specified a target task, also iterate its context and
+	 * deliver this event there too.
+	 */
+	if (task && task != current) {
+		struct perf_event_context *ctx;
+		struct trace_entry *entry = record;
+
+		rcu_read_lock();
+		ctx = rcu_dereference(task->perf_event_ctxp[perf_sw_context]);
+		if (!ctx)
+			goto unlock;
+
+		list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
+			if (event->attr.type != PERF_TYPE_TRACEPOINT)
+				continue;
+			if (event->attr.config != entry->type)
+				continue;
+			if (perf_tp_event_match(event, &data, regs))
+				perf_swevent_event(event, count, &data, regs);
+		}
+unlock:
+		rcu_read_unlock();
+	}
+
+	perf_swevent_put_recursion_context(rctx);
+}
+EXPORT_SYMBOL_GPL(perf_tp_event);
+
+static void tp_perf_event_destroy(struct perf_event *event)
+{
+	perf_trace_destroy(event);
+}
+
+static int perf_tp_event_init(struct perf_event *event)
+{
+	int err;
+
+	if (event->attr.type != PERF_TYPE_TRACEPOINT)
+		return -ENOENT;
+
+	/*
+	 * no branch sampling for tracepoint events
+	 */
+	if (has_branch_stack(event))
+		return -EOPNOTSUPP;
+
+	err = perf_trace_init(event);
+	if (err)
+		return err;
+
+	event->destroy = tp_perf_event_destroy;
+
+	return 0;
+}
+
+static struct pmu perf_tracepoint = {
+	.task_ctx_nr	= perf_sw_context,
+
+	.event_init	= perf_tp_event_init,
+	.add		= perf_trace_add,
+	.del		= perf_trace_del,
+	.start		= perf_swevent_start,
+	.stop		= perf_swevent_stop,
+	.read		= perf_swevent_read,
+};
+
+static inline void perf_tp_register(void)
+{
+	perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT);
+}
+
+static int perf_event_set_filter(struct perf_event *event, void __user *arg)
+{
+	char *filter_str;
+	int ret;
+
+	if (event->attr.type != PERF_TYPE_TRACEPOINT)
+		return -EINVAL;
+
+	filter_str = strndup_user(arg, PAGE_SIZE);
+	if (IS_ERR(filter_str))
+		return PTR_ERR(filter_str);
+
+	ret = ftrace_profile_set_filter(event, event->attr.config, filter_str);
+
+	kfree(filter_str);
+	return ret;
+}
+
+static void perf_event_free_filter(struct perf_event *event)
+{
+	ftrace_profile_free_filter(event);
+}
+
+#else
+
+static inline void perf_tp_register(void)
+{
+}
+
+static int perf_event_set_filter(struct perf_event *event, void __user *arg)
+{
+	return -ENOENT;
+}
+
+static void perf_event_free_filter(struct perf_event *event)
+{
+}
+
+#endif /* CONFIG_EVENT_TRACING */
+
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+void perf_bp_event(struct perf_event *bp, void *data)
+{
+	struct perf_sample_data sample;
+	struct pt_regs *regs = data;
+
+	perf_sample_data_init(&sample, bp->attr.bp_addr, 0);
+
+	if (!bp->hw.state && !perf_exclude_event(bp, regs))
+		perf_swevent_event(bp, 1, &sample, regs);
+}
+#endif
+
+/*
+ * hrtimer based swevent callback
+ */
+
+static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer)
+{
+	enum hrtimer_restart ret = HRTIMER_RESTART;
+	struct perf_sample_data data;
+	struct pt_regs *regs;
+	struct perf_event *event;
+	u64 period;
+
+	event = container_of(hrtimer, struct perf_event, hw.hrtimer);
+
+	if (event->state != PERF_EVENT_STATE_ACTIVE)
+		return HRTIMER_NORESTART;
+
+	event->pmu->read(event);
+
+	perf_sample_data_init(&data, 0, event->hw.last_period);
+	regs = get_irq_regs();
+
+	if (regs && !perf_exclude_event(event, regs)) {
+		if (!(event->attr.exclude_idle && is_idle_task(current)))
+			if (__perf_event_overflow(event, 1, &data, regs))
+				ret = HRTIMER_NORESTART;
+	}
+
+	period = max_t(u64, 10000, event->hw.sample_period);
+	hrtimer_forward_now(hrtimer, ns_to_ktime(period));
+
+	return ret;
+}
+
+static void perf_swevent_start_hrtimer(struct perf_event *event)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	s64 period;
+
+	if (!is_sampling_event(event))
+		return;
+
+	period = local64_read(&hwc->period_left);
+	if (period) {
+		if (period < 0)
+			period = 10000;
+
+		local64_set(&hwc->period_left, 0);
+	} else {
+		period = max_t(u64, 10000, hwc->sample_period);
+	}
+	__hrtimer_start_range_ns(&hwc->hrtimer,
+				ns_to_ktime(period), 0,
+				HRTIMER_MODE_REL_PINNED, 0);
+}
+
+static void perf_swevent_cancel_hrtimer(struct perf_event *event)
+{
+	struct hw_perf_event *hwc = &event->hw;
+
+	if (is_sampling_event(event)) {
+		ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer);
+		local64_set(&hwc->period_left, ktime_to_ns(remaining));
+
+		hrtimer_cancel(&hwc->hrtimer);
+	}
+}
+
+static void perf_swevent_init_hrtimer(struct perf_event *event)
+{
+	struct hw_perf_event *hwc = &event->hw;
+
+	if (!is_sampling_event(event))
+		return;
+
+	hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	hwc->hrtimer.function = perf_swevent_hrtimer;
+
+	/*
+	 * Since hrtimers have a fixed rate, we can do a static freq->period
+	 * mapping and avoid the whole period adjust feedback stuff.
+	 */
+	if (event->attr.freq) {
+		long freq = event->attr.sample_freq;
+
+		event->attr.sample_period = NSEC_PER_SEC / freq;
+		hwc->sample_period = event->attr.sample_period;
+		local64_set(&hwc->period_left, hwc->sample_period);
+		hwc->last_period = hwc->sample_period;
+		event->attr.freq = 0;
+	}
+}
+
+/*
+ * Software event: cpu wall time clock
+ */
+
+static void cpu_clock_event_update(struct perf_event *event)
+{
+	s64 prev;
+	u64 now;
+
+	now = local_clock();
+	prev = local64_xchg(&event->hw.prev_count, now);
+	local64_add(now - prev, &event->count);
+}
+
+static void cpu_clock_event_start(struct perf_event *event, int flags)
+{
+	local64_set(&event->hw.prev_count, local_clock());
+	perf_swevent_start_hrtimer(event);
+}
+
+static void cpu_clock_event_stop(struct perf_event *event, int flags)
+{
+	perf_swevent_cancel_hrtimer(event);
+	cpu_clock_event_update(event);
+}
+
+static int cpu_clock_event_add(struct perf_event *event, int flags)
+{
+	if (flags & PERF_EF_START)
+		cpu_clock_event_start(event, flags);
+
+	return 0;
+}
+
+static void cpu_clock_event_del(struct perf_event *event, int flags)
+{
+	cpu_clock_event_stop(event, flags);
+}
+
+static void cpu_clock_event_read(struct perf_event *event)
+{
+	cpu_clock_event_update(event);
+}
+
+static int cpu_clock_event_init(struct perf_event *event)
+{
+	if (event->attr.type != PERF_TYPE_SOFTWARE)
+		return -ENOENT;
+
+	if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK)
+		return -ENOENT;
+
+	/*
+	 * no branch sampling for software events
+	 */
+	if (has_branch_stack(event))
+		return -EOPNOTSUPP;
+
+	perf_swevent_init_hrtimer(event);
+
+	return 0;
+}
+
+static struct pmu perf_cpu_clock = {
+	.task_ctx_nr	= perf_sw_context,
+
+	.event_init	= cpu_clock_event_init,
+	.add		= cpu_clock_event_add,
+	.del		= cpu_clock_event_del,
+	.start		= cpu_clock_event_start,
+	.stop		= cpu_clock_event_stop,
+	.read		= cpu_clock_event_read,
+};
+
+/*
+ * Software event: task time clock
+ */
+
+static void task_clock_event_update(struct perf_event *event, u64 now)
+{
+	u64 prev;
+	s64 delta;
+
+	prev = local64_xchg(&event->hw.prev_count, now);
+	delta = now - prev;
+	local64_add(delta, &event->count);
+}
+
+static void task_clock_event_start(struct perf_event *event, int flags)
+{
+	local64_set(&event->hw.prev_count, event->ctx->time);
+	perf_swevent_start_hrtimer(event);
+}
+
+static void task_clock_event_stop(struct perf_event *event, int flags)
+{
+	perf_swevent_cancel_hrtimer(event);
+	task_clock_event_update(event, event->ctx->time);
+}
+
+static int task_clock_event_add(struct perf_event *event, int flags)
+{
+	if (flags & PERF_EF_START)
+		task_clock_event_start(event, flags);
+
+	return 0;
+}
+
+static void task_clock_event_del(struct perf_event *event, int flags)
+{
+	task_clock_event_stop(event, PERF_EF_UPDATE);
+}
+
+static void task_clock_event_read(struct perf_event *event)
+{
+	u64 now = perf_clock();
+	u64 delta = now - event->ctx->timestamp;
+	u64 time = event->ctx->time + delta;
+
+	task_clock_event_update(event, time);
+}
+
+static int task_clock_event_init(struct perf_event *event)
+{
+	if (event->attr.type != PERF_TYPE_SOFTWARE)
+		return -ENOENT;
+
+	if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK)
+		return -ENOENT;
+
+	/*
+	 * no branch sampling for software events
+	 */
+	if (has_branch_stack(event))
+		return -EOPNOTSUPP;
+
+	perf_swevent_init_hrtimer(event);
+
+	return 0;
+}
+
+static struct pmu perf_task_clock = {
+	.task_ctx_nr	= perf_sw_context,
+
+	.event_init	= task_clock_event_init,
+	.add		= task_clock_event_add,
+	.del		= task_clock_event_del,
+	.start		= task_clock_event_start,
+	.stop		= task_clock_event_stop,
+	.read		= task_clock_event_read,
+};
+
+static void perf_pmu_nop_void(struct pmu *pmu)
+{
+}
+
+static int perf_pmu_nop_int(struct pmu *pmu)
+{
+	return 0;
+}
+
+static void perf_pmu_start_txn(struct pmu *pmu)
+{
+	perf_pmu_disable(pmu);
+}
+
+static int perf_pmu_commit_txn(struct pmu *pmu)
+{
+	perf_pmu_enable(pmu);
+	return 0;
+}
+
+static void perf_pmu_cancel_txn(struct pmu *pmu)
+{
+	perf_pmu_enable(pmu);
+}
+
+static int perf_event_idx_default(struct perf_event *event)
+{
+	return 0;
+}
+
+/*
+ * Ensures all contexts with the same task_ctx_nr have the same
+ * pmu_cpu_context too.
+ */
+static struct perf_cpu_context __percpu *find_pmu_context(int ctxn)
+{
+	struct pmu *pmu;
+
+	if (ctxn < 0)
+		return NULL;
+
+	list_for_each_entry(pmu, &pmus, entry) {
+		if (pmu->task_ctx_nr == ctxn)
+			return pmu->pmu_cpu_context;
+	}
+
+	return NULL;
+}
+
+static void update_pmu_context(struct pmu *pmu, struct pmu *old_pmu)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu) {
+		struct perf_cpu_context *cpuctx;
+
+		cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
+
+		if (cpuctx->unique_pmu == old_pmu)
+			cpuctx->unique_pmu = pmu;
+	}
+}
+
+static void free_pmu_context(struct pmu *pmu)
+{
+	struct pmu *i;
+
+	mutex_lock(&pmus_lock);
+	/*
+	 * Like a real lame refcount.
+	 */
+	list_for_each_entry(i, &pmus, entry) {
+		if (i->pmu_cpu_context == pmu->pmu_cpu_context) {
+			update_pmu_context(i, pmu);
+			goto out;
+		}
+	}
+
+	free_percpu(pmu->pmu_cpu_context);
+out:
+	mutex_unlock(&pmus_lock);
+}
+static struct idr pmu_idr;
+
+static ssize_t
+type_show(struct device *dev, struct device_attribute *attr, char *page)
+{
+	struct pmu *pmu = dev_get_drvdata(dev);
+
+	return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->type);
+}
+static DEVICE_ATTR_RO(type);
+
+static ssize_t
+perf_event_mux_interval_ms_show(struct device *dev,
+				struct device_attribute *attr,
+				char *page)
+{
+	struct pmu *pmu = dev_get_drvdata(dev);
+
+	return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->hrtimer_interval_ms);
+}
+
+static ssize_t
+perf_event_mux_interval_ms_store(struct device *dev,
+				 struct device_attribute *attr,
+				 const char *buf, size_t count)
+{
+	struct pmu *pmu = dev_get_drvdata(dev);
+	int timer, cpu, ret;
+
+	ret = kstrtoint(buf, 0, &timer);
+	if (ret)
+		return ret;
+
+	if (timer < 1)
+		return -EINVAL;
+
+	/* same value, noting to do */
+	if (timer == pmu->hrtimer_interval_ms)
+		return count;
+
+	pmu->hrtimer_interval_ms = timer;
+
+	/* update all cpuctx for this PMU */
+	for_each_possible_cpu(cpu) {
+		struct perf_cpu_context *cpuctx;
+		cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
+		cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer);
+
+		if (hrtimer_active(&cpuctx->hrtimer))
+			hrtimer_forward_now(&cpuctx->hrtimer, cpuctx->hrtimer_interval);
+	}
+
+	return count;
+}
+static DEVICE_ATTR_RW(perf_event_mux_interval_ms);
+
+static struct attribute *pmu_dev_attrs[] = {
+	&dev_attr_type.attr,
+	&dev_attr_perf_event_mux_interval_ms.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(pmu_dev);
+
+static int pmu_bus_running;
+static struct bus_type pmu_bus = {
+	.name		= "event_source",
+	.dev_groups	= pmu_dev_groups,
+};
+
+static void pmu_dev_release(struct device *dev)
+{
+	kfree(dev);
+}
+
+static int pmu_dev_alloc(struct pmu *pmu)
+{
+	int ret = -ENOMEM;
+
+	pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL);
+	if (!pmu->dev)
+		goto out;
+
+	pmu->dev->groups = pmu->attr_groups;
+	device_initialize(pmu->dev);
+	ret = dev_set_name(pmu->dev, "%s", pmu->name);
+	if (ret)
+		goto free_dev;
+
+	dev_set_drvdata(pmu->dev, pmu);
+	pmu->dev->bus = &pmu_bus;
+	pmu->dev->release = pmu_dev_release;
+	ret = device_add(pmu->dev);
+	if (ret)
+		goto free_dev;
+
+out:
+	return ret;
+
+free_dev:
+	put_device(pmu->dev);
+	goto out;
+}
+
+static struct lock_class_key cpuctx_mutex;
+static struct lock_class_key cpuctx_lock;
+
+int perf_pmu_register(struct pmu *pmu, const char *name, int type)
+{
+	int cpu, ret;
+
+	mutex_lock(&pmus_lock);
+	ret = -ENOMEM;
+	pmu->pmu_disable_count = alloc_percpu(int);
+	if (!pmu->pmu_disable_count)
+		goto unlock;
+
+	pmu->type = -1;
+	if (!name)
+		goto skip_type;
+	pmu->name = name;
+
+	if (type < 0) {
+		type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL);
+		if (type < 0) {
+			ret = type;
+			goto free_pdc;
+		}
+	}
+	pmu->type = type;
+
+	if (pmu_bus_running) {
+		ret = pmu_dev_alloc(pmu);
+		if (ret)
+			goto free_idr;
+	}
+
+skip_type:
+	pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr);
+	if (pmu->pmu_cpu_context)
+		goto got_cpu_context;
+
+	ret = -ENOMEM;
+	pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context);
+	if (!pmu->pmu_cpu_context)
+		goto free_dev;
+
+	for_each_possible_cpu(cpu) {
+		struct perf_cpu_context *cpuctx;
+
+		cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
+		__perf_event_init_context(&cpuctx->ctx);
+		lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex);
+		lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock);
+		cpuctx->ctx.type = cpu_context;
+		cpuctx->ctx.pmu = pmu;
+
+		__perf_cpu_hrtimer_init(cpuctx, cpu);
+
+		INIT_LIST_HEAD(&cpuctx->rotation_list);
+		cpuctx->unique_pmu = pmu;
+	}
+
+got_cpu_context:
+	if (!pmu->start_txn) {
+		if (pmu->pmu_enable) {
+			/*
+			 * If we have pmu_enable/pmu_disable calls, install
+			 * transaction stubs that use that to try and batch
+			 * hardware accesses.
+			 */
+			pmu->start_txn  = perf_pmu_start_txn;
+			pmu->commit_txn = perf_pmu_commit_txn;
+			pmu->cancel_txn = perf_pmu_cancel_txn;
+		} else {
+			pmu->start_txn  = perf_pmu_nop_void;
+			pmu->commit_txn = perf_pmu_nop_int;
+			pmu->cancel_txn = perf_pmu_nop_void;
+		}
+	}
+
+	if (!pmu->pmu_enable) {
+		pmu->pmu_enable  = perf_pmu_nop_void;
+		pmu->pmu_disable = perf_pmu_nop_void;
+	}
+
+	if (!pmu->event_idx)
+		pmu->event_idx = perf_event_idx_default;
+
+	list_add_rcu(&pmu->entry, &pmus);
+	ret = 0;
+unlock:
+	mutex_unlock(&pmus_lock);
+
+	return ret;
+
+free_dev:
+	device_del(pmu->dev);
+	put_device(pmu->dev);
+
+free_idr:
+	if (pmu->type >= PERF_TYPE_MAX)
+		idr_remove(&pmu_idr, pmu->type);
+
+free_pdc:
+	free_percpu(pmu->pmu_disable_count);
+	goto unlock;
+}
+EXPORT_SYMBOL_GPL(perf_pmu_register);
+
+void perf_pmu_unregister(struct pmu *pmu)
+{
+	mutex_lock(&pmus_lock);
+	list_del_rcu(&pmu->entry);
+	mutex_unlock(&pmus_lock);
+
+	/*
+	 * We dereference the pmu list under both SRCU and regular RCU, so
+	 * synchronize against both of those.
+	 */
+	synchronize_srcu(&pmus_srcu);
+	synchronize_rcu();
+
+	free_percpu(pmu->pmu_disable_count);
+	if (pmu->type >= PERF_TYPE_MAX)
+		idr_remove(&pmu_idr, pmu->type);
+	device_del(pmu->dev);
+	put_device(pmu->dev);
+	free_pmu_context(pmu);
+}
+EXPORT_SYMBOL_GPL(perf_pmu_unregister);
+
+struct pmu *perf_init_event(struct perf_event *event)
+{
+	struct pmu *pmu = NULL;
+	int idx;
+	int ret;
+
+	idx = srcu_read_lock(&pmus_srcu);
+
+	rcu_read_lock();
+	pmu = idr_find(&pmu_idr, event->attr.type);
+	rcu_read_unlock();
+	if (pmu) {
+		if (!try_module_get(pmu->module)) {
+			pmu = ERR_PTR(-ENODEV);
+			goto unlock;
+		}
+		event->pmu = pmu;
+		ret = pmu->event_init(event);
+		if (ret)
+			pmu = ERR_PTR(ret);
+		goto unlock;
+	}
+
+	list_for_each_entry_rcu(pmu, &pmus, entry) {
+		if (!try_module_get(pmu->module)) {
+			pmu = ERR_PTR(-ENODEV);
+			goto unlock;
+		}
+		event->pmu = pmu;
+		ret = pmu->event_init(event);
+		if (!ret)
+			goto unlock;
+
+		if (ret != -ENOENT) {
+			pmu = ERR_PTR(ret);
+			goto unlock;
+		}
+	}
+	pmu = ERR_PTR(-ENOENT);
+unlock:
+	srcu_read_unlock(&pmus_srcu, idx);
+
+	return pmu;
+}
+
+static void account_event_cpu(struct perf_event *event, int cpu)
+{
+	if (event->parent)
+		return;
+
+	if (has_branch_stack(event)) {
+		if (!(event->attach_state & PERF_ATTACH_TASK))
+			atomic_inc(&per_cpu(perf_branch_stack_events, cpu));
+	}
+	if (is_cgroup_event(event))
+		atomic_inc(&per_cpu(perf_cgroup_events, cpu));
+}
+
+static void account_event(struct perf_event *event)
+{
+	if (event->parent)
+		return;
+
+	if (event->attach_state & PERF_ATTACH_TASK)
+		static_key_slow_inc(&perf_sched_events.key);
+	if (event->attr.mmap || event->attr.mmap_data)
+		atomic_inc(&nr_mmap_events);
+	if (event->attr.comm)
+		atomic_inc(&nr_comm_events);
+	if (event->attr.task)
+		atomic_inc(&nr_task_events);
+	if (event->attr.freq) {
+		if (atomic_inc_return(&nr_freq_events) == 1)
+			tick_nohz_full_kick_all();
+	}
+	if (has_branch_stack(event))
+		static_key_slow_inc(&perf_sched_events.key);
+	if (is_cgroup_event(event))
+		static_key_slow_inc(&perf_sched_events.key);
+
+	account_event_cpu(event, event->cpu);
+}
+
+/*
+ * Allocate and initialize a event structure
+ */
+static struct perf_event *
+perf_event_alloc(struct perf_event_attr *attr, int cpu,
+		 struct task_struct *task,
+		 struct perf_event *group_leader,
+		 struct perf_event *parent_event,
+		 perf_overflow_handler_t overflow_handler,
+		 void *context)
+{
+	struct pmu *pmu;
+	struct perf_event *event;
+	struct hw_perf_event *hwc;
+	long err = -EINVAL;
+
+	if ((unsigned)cpu >= nr_cpu_ids) {
+		if (!task || cpu != -1)
+			return ERR_PTR(-EINVAL);
+	}
+
+	event = kzalloc(sizeof(*event), GFP_KERNEL);
+	if (!event)
+		return ERR_PTR(-ENOMEM);
+
+	/*
+	 * Single events are their own group leaders, with an
+	 * empty sibling list:
+	 */
+	if (!group_leader)
+		group_leader = event;
+
+	mutex_init(&event->child_mutex);
+	INIT_LIST_HEAD(&event->child_list);
+
+	INIT_LIST_HEAD(&event->group_entry);
+	INIT_LIST_HEAD(&event->event_entry);
+	INIT_LIST_HEAD(&event->sibling_list);
+	INIT_LIST_HEAD(&event->rb_entry);
+	INIT_LIST_HEAD(&event->active_entry);
+	INIT_HLIST_NODE(&event->hlist_entry);
+
+
+	init_waitqueue_head(&event->waitq);
+	init_irq_work(&event->pending, perf_pending_event);
+
+	mutex_init(&event->mmap_mutex);
+
+	atomic_long_set(&event->refcount, 1);
+	event->cpu		= cpu;
+	event->attr		= *attr;
+	event->group_leader	= group_leader;
+	event->pmu		= NULL;
+	event->oncpu		= -1;
+
+	event->parent		= parent_event;
+
+	event->ns		= get_pid_ns(task_active_pid_ns(current));
+	event->id		= atomic64_inc_return(&perf_event_id);
+
+	event->state		= PERF_EVENT_STATE_INACTIVE;
+
+	if (task) {
+		event->attach_state = PERF_ATTACH_TASK;
+
+		if (attr->type == PERF_TYPE_TRACEPOINT)
+			event->hw.tp_target = task;
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+		/*
+		 * hw_breakpoint is a bit difficult here..
+		 */
+		else if (attr->type == PERF_TYPE_BREAKPOINT)
+			event->hw.bp_target = task;
+#endif
+	}
+
+	if (!overflow_handler && parent_event) {
+		overflow_handler = parent_event->overflow_handler;
+		context = parent_event->overflow_handler_context;
+	}
+
+	event->overflow_handler	= overflow_handler;
+	event->overflow_handler_context = context;
+
+	perf_event__state_init(event);
+
+	pmu = NULL;
+
+	hwc = &event->hw;
+	hwc->sample_period = attr->sample_period;
+	if (attr->freq && attr->sample_freq)
+		hwc->sample_period = 1;
+	hwc->last_period = hwc->sample_period;
+
+	local64_set(&hwc->period_left, hwc->sample_period);
+
+	/*
+	 * we currently do not support PERF_FORMAT_GROUP on inherited events
+	 */
+	if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP))
+		goto err_ns;
+
+	pmu = perf_init_event(event);
+	if (!pmu)
+		goto err_ns;
+	else if (IS_ERR(pmu)) {
+		err = PTR_ERR(pmu);
+		goto err_ns;
+	}
+
+	if (!event->parent) {
+		if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) {
+			err = get_callchain_buffers();
+			if (err)
+				goto err_pmu;
+		}
+	}
+
+	return event;
+
+err_pmu:
+	if (event->destroy)
+		event->destroy(event);
+	module_put(pmu->module);
+err_ns:
+	if (event->ns)
+		put_pid_ns(event->ns);
+	kfree(event);
+
+	return ERR_PTR(err);
+}
+
+static int perf_copy_attr(struct perf_event_attr __user *uattr,
+			  struct perf_event_attr *attr)
+{
+	u32 size;
+	int ret;
+
+	if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0))
+		return -EFAULT;
+
+	/*
+	 * zero the full structure, so that a short copy will be nice.
+	 */
+	memset(attr, 0, sizeof(*attr));
+
+	ret = get_user(size, &uattr->size);
+	if (ret)
+		return ret;
+
+	if (size > PAGE_SIZE)	/* silly large */
+		goto err_size;
+
+	if (!size)		/* abi compat */
+		size = PERF_ATTR_SIZE_VER0;
+
+	if (size < PERF_ATTR_SIZE_VER0)
+		goto err_size;
+
+	/*
+	 * If we're handed a bigger struct than we know of,
+	 * ensure all the unknown bits are 0 - i.e. new
+	 * user-space does not rely on any kernel feature
+	 * extensions we dont know about yet.
+	 */
+	if (size > sizeof(*attr)) {
+		unsigned char __user *addr;
+		unsigned char __user *end;
+		unsigned char val;
+
+		addr = (void __user *)uattr + sizeof(*attr);
+		end  = (void __user *)uattr + size;
+
+		for (; addr < end; addr++) {
+			ret = get_user(val, addr);
+			if (ret)
+				return ret;
+			if (val)
+				goto err_size;
+		}
+		size = sizeof(*attr);
+	}
+
+	ret = copy_from_user(attr, uattr, size);
+	if (ret)
+		return -EFAULT;
+
+	if (attr->__reserved_1)
+		return -EINVAL;
+
+	if (attr->sample_type & ~(PERF_SAMPLE_MAX-1))
+		return -EINVAL;
+
+	if (attr->read_format & ~(PERF_FORMAT_MAX-1))
+		return -EINVAL;
+
+	if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) {
+		u64 mask = attr->branch_sample_type;
+
+		/* only using defined bits */
+		if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1))
+			return -EINVAL;
+
+		/* at least one branch bit must be set */
+		if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL))
+			return -EINVAL;
+
+		/* propagate priv level, when not set for branch */
+		if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) {
+
+			/* exclude_kernel checked on syscall entry */
+			if (!attr->exclude_kernel)
+				mask |= PERF_SAMPLE_BRANCH_KERNEL;
+
+			if (!attr->exclude_user)
+				mask |= PERF_SAMPLE_BRANCH_USER;
+
+			if (!attr->exclude_hv)
+				mask |= PERF_SAMPLE_BRANCH_HV;
+			/*
+			 * adjust user setting (for HW filter setup)
+			 */
+			attr->branch_sample_type = mask;
+		}
+		/* privileged levels capture (kernel, hv): check permissions */
+		if ((mask & PERF_SAMPLE_BRANCH_PERM_PLM)
+		    && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
+			return -EACCES;
+	}
+
+	if (attr->sample_type & PERF_SAMPLE_REGS_USER) {
+		ret = perf_reg_validate(attr->sample_regs_user);
+		if (ret)
+			return ret;
+	}
+
+	if (attr->sample_type & PERF_SAMPLE_STACK_USER) {
+		if (!arch_perf_have_user_stack_dump())
+			return -ENOSYS;
+
+		/*
+		 * We have __u32 type for the size, but so far
+		 * we can only use __u16 as maximum due to the
+		 * __u16 sample size limit.
+		 */
+		if (attr->sample_stack_user >= USHRT_MAX)
+			ret = -EINVAL;
+		else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64)))
+			ret = -EINVAL;
+	}
+
+out:
+	return ret;
+
+err_size:
+	put_user(sizeof(*attr), &uattr->size);
+	ret = -E2BIG;
+	goto out;
+}
+
+static int
+perf_event_set_output(struct perf_event *event, struct perf_event *output_event)
+{
+	struct ring_buffer *rb = NULL;
+	int ret = -EINVAL;
+
+	if (!output_event)
+		goto set;
+
+	/* don't allow circular references */
+	if (event == output_event)
+		goto out;
+
+	/*
+	 * Don't allow cross-cpu buffers
+	 */
+	if (output_event->cpu != event->cpu)
+		goto out;
+
+	/*
+	 * If its not a per-cpu rb, it must be the same task.
+	 */
+	if (output_event->cpu == -1 && output_event->ctx != event->ctx)
+		goto out;
+
+set:
+	mutex_lock(&event->mmap_mutex);
+	/* Can't redirect output if we've got an active mmap() */
+	if (atomic_read(&event->mmap_count))
+		goto unlock;
+
+	if (output_event) {
+		/* get the rb we want to redirect to */
+		rb = ring_buffer_get(output_event);
+		if (!rb)
+			goto unlock;
+	}
+
+	ring_buffer_attach(event, rb);
+
+	ret = 0;
+unlock:
+	mutex_unlock(&event->mmap_mutex);
+
+out:
+	return ret;
+}
+
+/**
+ * sys_perf_event_open - open a performance event, associate it to a task/cpu
+ *
+ * @attr_uptr:	event_id type attributes for monitoring/sampling
+ * @pid:		target pid
+ * @cpu:		target cpu
+ * @group_fd:		group leader event fd
+ */
+SYSCALL_DEFINE5(perf_event_open,
+		struct perf_event_attr __user *, attr_uptr,
+		pid_t, pid, int, cpu, int, group_fd, unsigned long, flags)
+{
+	struct perf_event *group_leader = NULL, *output_event = NULL;
+	struct perf_event *event, *sibling;
+	struct perf_event_attr attr;
+	struct perf_event_context *ctx;
+	struct file *event_file = NULL;
+	struct fd group = {NULL, 0};
+	struct task_struct *task = NULL;
+	struct pmu *pmu;
+	int event_fd;
+	int move_group = 0;
+	int err;
+	int f_flags = O_RDWR;
+
+	/* for future expandability... */
+	if (flags & ~PERF_FLAG_ALL)
+		return -EINVAL;
+
+	err = perf_copy_attr(attr_uptr, &attr);
+	if (err)
+		return err;
+
+	if (!attr.exclude_kernel) {
+		if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
+			return -EACCES;
+	}
+
+	if (attr.freq) {
+		if (attr.sample_freq > sysctl_perf_event_sample_rate)
+			return -EINVAL;
+	} else {
+		if (attr.sample_period & (1ULL << 63))
+			return -EINVAL;
+	}
+
+	/*
+	 * In cgroup mode, the pid argument is used to pass the fd
+	 * opened to the cgroup directory in cgroupfs. The cpu argument
+	 * designates the cpu on which to monitor threads from that
+	 * cgroup.
+	 */
+	if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1))
+		return -EINVAL;
+
+	if (flags & PERF_FLAG_FD_CLOEXEC)
+		f_flags |= O_CLOEXEC;
+
+	event_fd = get_unused_fd_flags(f_flags);
+	if (event_fd < 0)
+		return event_fd;
+
+	if (group_fd != -1) {
+		err = perf_fget_light(group_fd, &group);
+		if (err)
+			goto err_fd;
+		group_leader = group.file->private_data;
+		if (flags & PERF_FLAG_FD_OUTPUT)
+			output_event = group_leader;
+		if (flags & PERF_FLAG_FD_NO_GROUP)
+			group_leader = NULL;
+	}
+
+	if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) {
+		task = find_lively_task_by_vpid(pid);
+		if (IS_ERR(task)) {
+			err = PTR_ERR(task);
+			goto err_group_fd;
+		}
+	}
+
+	if (task && group_leader &&
+	    group_leader->attr.inherit != attr.inherit) {
+		err = -EINVAL;
+		goto err_task;
+	}
+
+	get_online_cpus();
+
+	event = perf_event_alloc(&attr, cpu, task, group_leader, NULL,
+				 NULL, NULL);
+	if (IS_ERR(event)) {
+		err = PTR_ERR(event);
+		goto err_cpus;
+	}
+
+	if (flags & PERF_FLAG_PID_CGROUP) {
+		err = perf_cgroup_connect(pid, event, &attr, group_leader);
+		if (err) {
+			__free_event(event);
+			goto err_cpus;
+		}
+	}
+
+	if (is_sampling_event(event)) {
+		if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) {
+			err = -ENOTSUPP;
+			goto err_alloc;
+		}
+	}
+
+	account_event(event);
+
+	/*
+	 * Special case software events and allow them to be part of
+	 * any hardware group.
+	 */
+	pmu = event->pmu;
+
+	if (group_leader &&
+	    (is_software_event(event) != is_software_event(group_leader))) {
+		if (is_software_event(event)) {
+			/*
+			 * If event and group_leader are not both a software
+			 * event, and event is, then group leader is not.
+			 *
+			 * Allow the addition of software events to !software
+			 * groups, this is safe because software events never
+			 * fail to schedule.
+			 */
+			pmu = group_leader->pmu;
+		} else if (is_software_event(group_leader) &&
+			   (group_leader->group_flags & PERF_GROUP_SOFTWARE)) {
+			/*
+			 * In case the group is a pure software group, and we
+			 * try to add a hardware event, move the whole group to
+			 * the hardware context.
+			 */
+			move_group = 1;
+		}
+	}
+
+	/*
+	 * Get the target context (task or percpu):
+	 */
+	ctx = find_get_context(pmu, task, event->cpu);
+	if (IS_ERR(ctx)) {
+		err = PTR_ERR(ctx);
+		goto err_alloc;
+	}
+
+	if (task) {
+		put_task_struct(task);
+		task = NULL;
+	}
+
+	/*
+	 * Look up the group leader (we will attach this event to it):
+	 */
+	if (group_leader) {
+		err = -EINVAL;
+
+		/*
+		 * Do not allow a recursive hierarchy (this new sibling
+		 * becoming part of another group-sibling):
+		 */
+		if (group_leader->group_leader != group_leader)
+			goto err_context;
+		/*
+		 * Do not allow to attach to a group in a different
+		 * task or CPU context:
+		 */
+		if (move_group) {
+			if (group_leader->ctx->type != ctx->type)
+				goto err_context;
+		} else {
+			if (group_leader->ctx != ctx)
+				goto err_context;
+		}
+
+		/*
+		 * Only a group leader can be exclusive or pinned
+		 */
+		if (attr.exclusive || attr.pinned)
+			goto err_context;
+	}
+
+	if (output_event) {
+		err = perf_event_set_output(event, output_event);
+		if (err)
+			goto err_context;
+	}
+
+	event_file = anon_inode_getfile("[perf_event]", &perf_fops, event,
+					f_flags);
+	if (IS_ERR(event_file)) {
+		err = PTR_ERR(event_file);
+		goto err_context;
+	}
+
+	if (move_group) {
+		struct perf_event_context *gctx = group_leader->ctx;
+
+		mutex_lock(&gctx->mutex);
+		perf_remove_from_context(group_leader, false);
+
+		/*
+		 * Removing from the context ends up with disabled
+		 * event. What we want here is event in the initial
+		 * startup state, ready to be add into new context.
+		 */
+		perf_event__state_init(group_leader);
+		list_for_each_entry(sibling, &group_leader->sibling_list,
+				    group_entry) {
+			perf_remove_from_context(sibling, false);
+			perf_event__state_init(sibling);
+			put_ctx(gctx);
+		}
+		mutex_unlock(&gctx->mutex);
+		put_ctx(gctx);
+	}
+
+	WARN_ON_ONCE(ctx->parent_ctx);
+	mutex_lock(&ctx->mutex);
+
+	if (move_group) {
+		synchronize_rcu();
+		perf_install_in_context(ctx, group_leader, group_leader->cpu);
+		get_ctx(ctx);
+		list_for_each_entry(sibling, &group_leader->sibling_list,
+				    group_entry) {
+			perf_install_in_context(ctx, sibling, sibling->cpu);
+			get_ctx(ctx);
+		}
+	}
+
+	perf_install_in_context(ctx, event, event->cpu);
+	perf_unpin_context(ctx);
+	mutex_unlock(&ctx->mutex);
+
+	put_online_cpus();
+
+	event->owner = current;
+
+	mutex_lock(&current->perf_event_mutex);
+	list_add_tail(&event->owner_entry, &current->perf_event_list);
+	mutex_unlock(&current->perf_event_mutex);
+
+	/*
+	 * Precalculate sample_data sizes
+	 */
+	perf_event__header_size(event);
+	perf_event__id_header_size(event);
+
+	/*
+	 * Drop the reference on the group_event after placing the
+	 * new event on the sibling_list. This ensures destruction
+	 * of the group leader will find the pointer to itself in
+	 * perf_group_detach().
+	 */
+	fdput(group);
+	fd_install(event_fd, event_file);
+	return event_fd;
+
+err_context:
+	perf_unpin_context(ctx);
+	put_ctx(ctx);
+err_alloc:
+	free_event(event);
+err_cpus:
+	put_online_cpus();
+err_task:
+	if (task)
+		put_task_struct(task);
+err_group_fd:
+	fdput(group);
+err_fd:
+	put_unused_fd(event_fd);
+	return err;
+}
+
+/**
+ * perf_event_create_kernel_counter
+ *
+ * @attr: attributes of the counter to create
+ * @cpu: cpu in which the counter is bound
+ * @task: task to profile (NULL for percpu)
+ */
+struct perf_event *
+perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
+				 struct task_struct *task,
+				 perf_overflow_handler_t overflow_handler,
+				 void *context)
+{
+	struct perf_event_context *ctx;
+	struct perf_event *event;
+	int err;
+
+	/*
+	 * Get the target context (task or percpu):
+	 */
+
+	event = perf_event_alloc(attr, cpu, task, NULL, NULL,
+				 overflow_handler, context);
+	if (IS_ERR(event)) {
+		err = PTR_ERR(event);
+		goto err;
+	}
+
+	/* Mark owner so we could distinguish it from user events. */
+	event->owner = EVENT_OWNER_KERNEL;
+
+	account_event(event);
+
+	ctx = find_get_context(event->pmu, task, cpu);
+	if (IS_ERR(ctx)) {
+		err = PTR_ERR(ctx);
+		goto err_free;
+	}
+
+	WARN_ON_ONCE(ctx->parent_ctx);
+	mutex_lock(&ctx->mutex);
+	perf_install_in_context(ctx, event, cpu);
+	perf_unpin_context(ctx);
+	mutex_unlock(&ctx->mutex);
+
+	return event;
+
+err_free:
+	free_event(event);
+err:
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter);
+
+void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu)
+{
+	struct perf_event_context *src_ctx;
+	struct perf_event_context *dst_ctx;
+	struct perf_event *event, *tmp;
+	LIST_HEAD(events);
+
+	src_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, src_cpu)->ctx;
+	dst_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, dst_cpu)->ctx;
+
+	mutex_lock(&src_ctx->mutex);
+	list_for_each_entry_safe(event, tmp, &src_ctx->event_list,
+				 event_entry) {
+		perf_remove_from_context(event, false);
+		unaccount_event_cpu(event, src_cpu);
+		put_ctx(src_ctx);
+		list_add(&event->migrate_entry, &events);
+	}
+	mutex_unlock(&src_ctx->mutex);
+
+	synchronize_rcu();
+
+	mutex_lock(&dst_ctx->mutex);
+	list_for_each_entry_safe(event, tmp, &events, migrate_entry) {
+		list_del(&event->migrate_entry);
+		if (event->state >= PERF_EVENT_STATE_OFF)
+			event->state = PERF_EVENT_STATE_INACTIVE;
+		account_event_cpu(event, dst_cpu);
+		perf_install_in_context(dst_ctx, event, dst_cpu);
+		get_ctx(dst_ctx);
+	}
+	mutex_unlock(&dst_ctx->mutex);
+}
+EXPORT_SYMBOL_GPL(perf_pmu_migrate_context);
+
+static void sync_child_event(struct perf_event *child_event,
+			       struct task_struct *child)
+{
+	struct perf_event *parent_event = child_event->parent;
+	u64 child_val;
+
+	if (child_event->attr.inherit_stat)
+		perf_event_read_event(child_event, child);
+
+	child_val = perf_event_count(child_event);
+
+	/*
+	 * Add back the child's count to the parent's count:
+	 */
+	atomic64_add(child_val, &parent_event->child_count);
+	atomic64_add(child_event->total_time_enabled,
+		     &parent_event->child_total_time_enabled);
+	atomic64_add(child_event->total_time_running,
+		     &parent_event->child_total_time_running);
+
+	/*
+	 * Remove this event from the parent's list
+	 */
+	WARN_ON_ONCE(parent_event->ctx->parent_ctx);
+	mutex_lock(&parent_event->child_mutex);
+	list_del_init(&child_event->child_list);
+	mutex_unlock(&parent_event->child_mutex);
+
+	/*
+	 * Make sure user/parent get notified, that we just
+	 * lost one event.
+	 */
+	perf_event_wakeup(parent_event);
+
+	/*
+	 * Release the parent event, if this was the last
+	 * reference to it.
+	 */
+	put_event(parent_event);
+}
+
+static void
+__perf_event_exit_task(struct perf_event *child_event,
+			 struct perf_event_context *child_ctx,
+			 struct task_struct *child)
+{
+	/*
+	 * Do not destroy the 'original' grouping; because of the context
+	 * switch optimization the original events could've ended up in a
+	 * random child task.
+	 *
+	 * If we were to destroy the original group, all group related
+	 * operations would cease to function properly after this random
+	 * child dies.
+	 *
+	 * Do destroy all inherited groups, we don't care about those
+	 * and being thorough is better.
+	 */
+	perf_remove_from_context(child_event, !!child_event->parent);
+
+	/*
+	 * It can happen that the parent exits first, and has events
+	 * that are still around due to the child reference. These
+	 * events need to be zapped.
+	 */
+	if (child_event->parent) {
+		sync_child_event(child_event, child);
+		free_event(child_event);
+	} else {
+		child_event->state = PERF_EVENT_STATE_EXIT;
+		perf_event_wakeup(child_event);
+	}
+}
+
+static void perf_event_exit_task_context(struct task_struct *child, int ctxn)
+{
+	struct perf_event *child_event, *next;
+	struct perf_event_context *child_ctx, *clone_ctx = NULL;
+	unsigned long flags;
+
+	if (likely(!child->perf_event_ctxp[ctxn])) {
+		perf_event_task(child, NULL, 0);
+		return;
+	}
+
+	local_irq_save(flags);
+	/*
+	 * We can't reschedule here because interrupts are disabled,
+	 * and either child is current or it is a task that can't be
+	 * scheduled, so we are now safe from rescheduling changing
+	 * our context.
+	 */
+	child_ctx = rcu_dereference_raw(child->perf_event_ctxp[ctxn]);
+
+	/*
+	 * Take the context lock here so that if find_get_context is
+	 * reading child->perf_event_ctxp, we wait until it has
+	 * incremented the context's refcount before we do put_ctx below.
+	 */
+	raw_spin_lock(&child_ctx->lock);
+	task_ctx_sched_out(child_ctx);
+	child->perf_event_ctxp[ctxn] = NULL;
+
+	/*
+	 * If this context is a clone; unclone it so it can't get
+	 * swapped to another process while we're removing all
+	 * the events from it.
+	 */
+	clone_ctx = unclone_ctx(child_ctx);
+	update_context_time(child_ctx);
+	raw_spin_unlock_irqrestore(&child_ctx->lock, flags);
+
+	if (clone_ctx)
+		put_ctx(clone_ctx);
+
+	/*
+	 * Report the task dead after unscheduling the events so that we
+	 * won't get any samples after PERF_RECORD_EXIT. We can however still
+	 * get a few PERF_RECORD_READ events.
+	 */
+	perf_event_task(child, child_ctx, 0);
+
+	/*
+	 * We can recurse on the same lock type through:
+	 *
+	 *   __perf_event_exit_task()
+	 *     sync_child_event()
+	 *       put_event()
+	 *         mutex_lock(&ctx->mutex)
+	 *
+	 * But since its the parent context it won't be the same instance.
+	 */
+	mutex_lock(&child_ctx->mutex);
+
+	list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry)
+		__perf_event_exit_task(child_event, child_ctx, child);
+
+	mutex_unlock(&child_ctx->mutex);
+
+	put_ctx(child_ctx);
+}
+
+/*
+ * When a child task exits, feed back event values to parent events.
+ */
+void perf_event_exit_task(struct task_struct *child)
+{
+	struct perf_event *event, *tmp;
+	int ctxn;
+
+	mutex_lock(&child->perf_event_mutex);
+	list_for_each_entry_safe(event, tmp, &child->perf_event_list,
+				 owner_entry) {
+		list_del_init(&event->owner_entry);
+
+		/*
+		 * Ensure the list deletion is visible before we clear
+		 * the owner, closes a race against perf_release() where
+		 * we need to serialize on the owner->perf_event_mutex.
+		 */
+		smp_wmb();
+		event->owner = NULL;
+	}
+	mutex_unlock(&child->perf_event_mutex);
+
+	for_each_task_context_nr(ctxn)
+		perf_event_exit_task_context(child, ctxn);
+}
+
+static void perf_free_event(struct perf_event *event,
+			    struct perf_event_context *ctx)
+{
+	struct perf_event *parent = event->parent;
+
+	if (WARN_ON_ONCE(!parent))
+		return;
+
+	mutex_lock(&parent->child_mutex);
+	list_del_init(&event->child_list);
+	mutex_unlock(&parent->child_mutex);
+
+	put_event(parent);
+
+	perf_group_detach(event);
+	list_del_event(event, ctx);
+	free_event(event);
+}
+
+/*
+ * free an unexposed, unused context as created by inheritance by
+ * perf_event_init_task below, used by fork() in case of fail.
+ */
+void perf_event_free_task(struct task_struct *task)
+{
+	struct perf_event_context *ctx;
+	struct perf_event *event, *tmp;
+	int ctxn;
+
+	for_each_task_context_nr(ctxn) {
+		ctx = task->perf_event_ctxp[ctxn];
+		if (!ctx)
+			continue;
+
+		mutex_lock(&ctx->mutex);
+again:
+		list_for_each_entry_safe(event, tmp, &ctx->pinned_groups,
+				group_entry)
+			perf_free_event(event, ctx);
+
+		list_for_each_entry_safe(event, tmp, &ctx->flexible_groups,
+				group_entry)
+			perf_free_event(event, ctx);
+
+		if (!list_empty(&ctx->pinned_groups) ||
+				!list_empty(&ctx->flexible_groups))
+			goto again;
+
+		mutex_unlock(&ctx->mutex);
+
+		put_ctx(ctx);
+	}
+}
+
+void perf_event_delayed_put(struct task_struct *task)
+{
+	int ctxn;
+
+	for_each_task_context_nr(ctxn)
+		WARN_ON_ONCE(task->perf_event_ctxp[ctxn]);
+}
+
+/*
+ * inherit a event from parent task to child task:
+ */
+static struct perf_event *
+inherit_event(struct perf_event *parent_event,
+	      struct task_struct *parent,
+	      struct perf_event_context *parent_ctx,
+	      struct task_struct *child,
+	      struct perf_event *group_leader,
+	      struct perf_event_context *child_ctx)
+{
+	enum perf_event_active_state parent_state = parent_event->state;
+	struct perf_event *child_event;
+	unsigned long flags;
+
+	/*
+	 * Instead of creating recursive hierarchies of events,
+	 * we link inherited events back to the original parent,
+	 * which has a filp for sure, which we use as the reference
+	 * count:
+	 */
+	if (parent_event->parent)
+		parent_event = parent_event->parent;
+
+	child_event = perf_event_alloc(&parent_event->attr,
+					   parent_event->cpu,
+					   child,
+					   group_leader, parent_event,
+				           NULL, NULL);
+	if (IS_ERR(child_event))
+		return child_event;
+
+	if (is_orphaned_event(parent_event) ||
+	    !atomic_long_inc_not_zero(&parent_event->refcount)) {
+		free_event(child_event);
+		return NULL;
+	}
+
+	get_ctx(child_ctx);
+
+	/*
+	 * Make the child state follow the state of the parent event,
+	 * not its attr.disabled bit.  We hold the parent's mutex,
+	 * so we won't race with perf_event_{en, dis}able_family.
+	 */
+	if (parent_state >= PERF_EVENT_STATE_INACTIVE)
+		child_event->state = PERF_EVENT_STATE_INACTIVE;
+	else
+		child_event->state = PERF_EVENT_STATE_OFF;
+
+	if (parent_event->attr.freq) {
+		u64 sample_period = parent_event->hw.sample_period;
+		struct hw_perf_event *hwc = &child_event->hw;
+
+		hwc->sample_period = sample_period;
+		hwc->last_period   = sample_period;
+
+		local64_set(&hwc->period_left, sample_period);
+	}
+
+	child_event->ctx = child_ctx;
+	child_event->overflow_handler = parent_event->overflow_handler;
+	child_event->overflow_handler_context
+		= parent_event->overflow_handler_context;
+
+	/*
+	 * Precalculate sample_data sizes
+	 */
+	perf_event__header_size(child_event);
+	perf_event__id_header_size(child_event);
+
+	/*
+	 * Link it up in the child's context:
+	 */
+	raw_spin_lock_irqsave(&child_ctx->lock, flags);
+	add_event_to_ctx(child_event, child_ctx);
+	raw_spin_unlock_irqrestore(&child_ctx->lock, flags);
+
+	/*
+	 * Link this into the parent event's child list
+	 */
+	WARN_ON_ONCE(parent_event->ctx->parent_ctx);
+	mutex_lock(&parent_event->child_mutex);
+	list_add_tail(&child_event->child_list, &parent_event->child_list);
+	mutex_unlock(&parent_event->child_mutex);
+
+	return child_event;
+}
+
+static int inherit_group(struct perf_event *parent_event,
+	      struct task_struct *parent,
+	      struct perf_event_context *parent_ctx,
+	      struct task_struct *child,
+	      struct perf_event_context *child_ctx)
+{
+	struct perf_event *leader;
+	struct perf_event *sub;
+	struct perf_event *child_ctr;
+
+	leader = inherit_event(parent_event, parent, parent_ctx,
+				 child, NULL, child_ctx);
+	if (IS_ERR(leader))
+		return PTR_ERR(leader);
+	list_for_each_entry(sub, &parent_event->sibling_list, group_entry) {
+		child_ctr = inherit_event(sub, parent, parent_ctx,
+					    child, leader, child_ctx);
+		if (IS_ERR(child_ctr))
+			return PTR_ERR(child_ctr);
+	}
+	return 0;
+}
+
+static int
+inherit_task_group(struct perf_event *event, struct task_struct *parent,
+		   struct perf_event_context *parent_ctx,
+		   struct task_struct *child, int ctxn,
+		   int *inherited_all)
+{
+	int ret;
+	struct perf_event_context *child_ctx;
+
+	if (!event->attr.inherit) {
+		*inherited_all = 0;
+		return 0;
+	}
+
+	child_ctx = child->perf_event_ctxp[ctxn];
+	if (!child_ctx) {
+		/*
+		 * This is executed from the parent task context, so
+		 * inherit events that have been marked for cloning.
+		 * First allocate and initialize a context for the
+		 * child.
+		 */
+
+		child_ctx = alloc_perf_context(parent_ctx->pmu, child);
+		if (!child_ctx)
+			return -ENOMEM;
+
+		child->perf_event_ctxp[ctxn] = child_ctx;
+	}
+
+	ret = inherit_group(event, parent, parent_ctx,
+			    child, child_ctx);
+
+	if (ret)
+		*inherited_all = 0;
+
+	return ret;
+}
+
+/*
+ * Initialize the perf_event context in task_struct
+ */
+static int perf_event_init_context(struct task_struct *child, int ctxn)
+{
+	struct perf_event_context *child_ctx, *parent_ctx;
+	struct perf_event_context *cloned_ctx;
+	struct perf_event *event;
+	struct task_struct *parent = current;
+	int inherited_all = 1;
+	unsigned long flags;
+	int ret = 0;
+
+	if (likely(!parent->perf_event_ctxp[ctxn]))
+		return 0;
+
+	/*
+	 * If the parent's context is a clone, pin it so it won't get
+	 * swapped under us.
+	 */
+	parent_ctx = perf_pin_task_context(parent, ctxn);
+	if (!parent_ctx)
+		return 0;
+
+	/*
+	 * No need to check if parent_ctx != NULL here; since we saw
+	 * it non-NULL earlier, the only reason for it to become NULL
+	 * is if we exit, and since we're currently in the middle of
+	 * a fork we can't be exiting at the same time.
+	 */
+
+	/*
+	 * Lock the parent list. No need to lock the child - not PID
+	 * hashed yet and not running, so nobody can access it.
+	 */
+	mutex_lock(&parent_ctx->mutex);
+
+	/*
+	 * We dont have to disable NMIs - we are only looking at
+	 * the list, not manipulating it:
+	 */
+	list_for_each_entry(event, &parent_ctx->pinned_groups, group_entry) {
+		ret = inherit_task_group(event, parent, parent_ctx,
+					 child, ctxn, &inherited_all);
+		if (ret)
+			break;
+	}
+
+	/*
+	 * We can't hold ctx->lock when iterating the ->flexible_group list due
+	 * to allocations, but we need to prevent rotation because
+	 * rotate_ctx() will change the list from interrupt context.
+	 */
+	raw_spin_lock_irqsave(&parent_ctx->lock, flags);
+	parent_ctx->rotate_disable = 1;
+	raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);
+
+	list_for_each_entry(event, &parent_ctx->flexible_groups, group_entry) {
+		ret = inherit_task_group(event, parent, parent_ctx,
+					 child, ctxn, &inherited_all);
+		if (ret)
+			break;
+	}
+
+	raw_spin_lock_irqsave(&parent_ctx->lock, flags);
+	parent_ctx->rotate_disable = 0;
+
+	child_ctx = child->perf_event_ctxp[ctxn];
+
+	if (child_ctx && inherited_all) {
+		/*
+		 * Mark the child context as a clone of the parent
+		 * context, or of whatever the parent is a clone of.
+		 *
+		 * Note that if the parent is a clone, the holding of
+		 * parent_ctx->lock avoids it from being uncloned.
+		 */
+		cloned_ctx = parent_ctx->parent_ctx;
+		if (cloned_ctx) {
+			child_ctx->parent_ctx = cloned_ctx;
+			child_ctx->parent_gen = parent_ctx->parent_gen;
+		} else {
+			child_ctx->parent_ctx = parent_ctx;
+			child_ctx->parent_gen = parent_ctx->generation;
+		}
+		get_ctx(child_ctx->parent_ctx);
+	}
+
+	raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);
+	mutex_unlock(&parent_ctx->mutex);
+
+	perf_unpin_context(parent_ctx);
+	put_ctx(parent_ctx);
+
+	return ret;
+}
+
+/*
+ * Initialize the perf_event context in task_struct
+ */
+int perf_event_init_task(struct task_struct *child)
+{
+	int ctxn, ret;
+
+	memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp));
+	mutex_init(&child->perf_event_mutex);
+	INIT_LIST_HEAD(&child->perf_event_list);
+
+	for_each_task_context_nr(ctxn) {
+		ret = perf_event_init_context(child, ctxn);
+		if (ret) {
+			perf_event_free_task(child);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static void __init perf_event_init_all_cpus(void)
+{
+	struct swevent_htable *swhash;
+	int cpu;
+
+	for_each_possible_cpu(cpu) {
+		swhash = &per_cpu(swevent_htable, cpu);
+		mutex_init(&swhash->hlist_mutex);
+		INIT_LIST_HEAD(&per_cpu(rotation_list, cpu));
+	}
+}
+
+static void perf_event_init_cpu(int cpu)
+{
+	struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
+
+	mutex_lock(&swhash->hlist_mutex);
+	swhash->online = true;
+	if (swhash->hlist_refcount > 0) {
+		struct swevent_hlist *hlist;
+
+		hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu));
+		WARN_ON(!hlist);
+		rcu_assign_pointer(swhash->swevent_hlist, hlist);
+	}
+	mutex_unlock(&swhash->hlist_mutex);
+}
+
+#if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC
+static void perf_pmu_rotate_stop(struct pmu *pmu)
+{
+	struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
+
+	WARN_ON(!irqs_disabled());
+
+	list_del_init(&cpuctx->rotation_list);
+}
+
+static void __perf_event_exit_context(void *__info)
+{
+	struct remove_event re = { .detach_group = true };
+	struct perf_event_context *ctx = __info;
+
+	perf_pmu_rotate_stop(ctx->pmu);
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(re.event, &ctx->event_list, event_entry)
+		__perf_remove_from_context(&re);
+	rcu_read_unlock();
+}
+
+static void perf_event_exit_cpu_context(int cpu)
+{
+	struct perf_event_context *ctx;
+	struct pmu *pmu;
+	int idx;
+
+	idx = srcu_read_lock(&pmus_srcu);
+	list_for_each_entry_rcu(pmu, &pmus, entry) {
+		ctx = &per_cpu_ptr(pmu->pmu_cpu_context, cpu)->ctx;
+
+		mutex_lock(&ctx->mutex);
+		smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1);
+		mutex_unlock(&ctx->mutex);
+	}
+	srcu_read_unlock(&pmus_srcu, idx);
+}
+
+static void perf_event_exit_cpu(int cpu)
+{
+	struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
+
+	perf_event_exit_cpu_context(cpu);
+
+	mutex_lock(&swhash->hlist_mutex);
+	swhash->online = false;
+	swevent_hlist_release(swhash);
+	mutex_unlock(&swhash->hlist_mutex);
+}
+#else
+static inline void perf_event_exit_cpu(int cpu) { }
+#endif
+
+static int
+perf_reboot(struct notifier_block *notifier, unsigned long val, void *v)
+{
+	int cpu;
+
+	for_each_online_cpu(cpu)
+		perf_event_exit_cpu(cpu);
+
+	return NOTIFY_OK;
+}
+
+/*
+ * Run the perf reboot notifier at the very last possible moment so that
+ * the generic watchdog code runs as long as possible.
+ */
+static struct notifier_block perf_reboot_notifier = {
+	.notifier_call = perf_reboot,
+	.priority = INT_MIN,
+};
+
+static int
+perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu)
+{
+	unsigned int cpu = (long)hcpu;
+
+	switch (action & ~CPU_TASKS_FROZEN) {
+
+	case CPU_UP_PREPARE:
+	case CPU_DOWN_FAILED:
+		perf_event_init_cpu(cpu);
+		break;
+
+	case CPU_UP_CANCELED:
+	case CPU_DOWN_PREPARE:
+		perf_event_exit_cpu(cpu);
+		break;
+	default:
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
+void __init perf_event_init(void)
+{
+	int ret;
+
+	idr_init(&pmu_idr);
+
+	perf_event_init_all_cpus();
+	init_srcu_struct(&pmus_srcu);
+	perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE);
+	perf_pmu_register(&perf_cpu_clock, NULL, -1);
+	perf_pmu_register(&perf_task_clock, NULL, -1);
+	perf_tp_register();
+	perf_cpu_notifier(perf_cpu_notify);
+	register_reboot_notifier(&perf_reboot_notifier);
+
+	ret = init_hw_breakpoint();
+	WARN(ret, "hw_breakpoint initialization failed with: %d", ret);
+
+	/* do not patch jump label more than once per second */
+	jump_label_rate_limit(&perf_sched_events, HZ);
+
+	/*
+	 * Build time assertion that we keep the data_head at the intended
+	 * location.  IOW, validation we got the __reserved[] size right.
+	 */
+	BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head))
+		     != 1024);
+}
+
+static int __init perf_event_sysfs_init(void)
+{
+	struct pmu *pmu;
+	int ret;
+
+	mutex_lock(&pmus_lock);
+
+	ret = bus_register(&pmu_bus);
+	if (ret)
+		goto unlock;
+
+	list_for_each_entry(pmu, &pmus, entry) {
+		if (!pmu->name || pmu->type < 0)
+			continue;
+
+		ret = pmu_dev_alloc(pmu);
+		WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret);
+	}
+	pmu_bus_running = 1;
+	ret = 0;
+
+unlock:
+	mutex_unlock(&pmus_lock);
+
+	return ret;
+}
+device_initcall(perf_event_sysfs_init);
+
+#ifdef CONFIG_CGROUP_PERF
+static struct cgroup_subsys_state *
+perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
+{
+	struct perf_cgroup *jc;
+
+	jc = kzalloc(sizeof(*jc), GFP_KERNEL);
+	if (!jc)
+		return ERR_PTR(-ENOMEM);
+
+	jc->info = alloc_percpu(struct perf_cgroup_info);
+	if (!jc->info) {
+		kfree(jc);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	return &jc->css;
+}
+
+static void perf_cgroup_css_free(struct cgroup_subsys_state *css)
+{
+	struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css);
+
+	free_percpu(jc->info);
+	kfree(jc);
+}
+
+static int __perf_cgroup_move(void *info)
+{
+	struct task_struct *task = info;
+	perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN);
+	return 0;
+}
+
+static void perf_cgroup_attach(struct cgroup_subsys_state *css,
+			       struct cgroup_taskset *tset)
+{
+	struct task_struct *task;
+
+	cgroup_taskset_for_each(task, tset)
+		task_function_call(task, __perf_cgroup_move, task);
+}
+
+static void perf_cgroup_exit(struct cgroup_subsys_state *css,
+			     struct cgroup_subsys_state *old_css,
+			     struct task_struct *task)
+{
+	/*
+	 * cgroup_exit() is called in the copy_process() failure path.
+	 * Ignore this case since the task hasn't ran yet, this avoids
+	 * trying to poke a half freed task state from generic code.
+	 */
+	if (!(task->flags & PF_EXITING))
+		return;
+
+	task_function_call(task, __perf_cgroup_move, task);
+}
+
+struct cgroup_subsys perf_event_cgrp_subsys = {
+	.css_alloc	= perf_cgroup_css_alloc,
+	.css_free	= perf_cgroup_css_free,
+	.exit		= perf_cgroup_exit,
+	.attach		= perf_cgroup_attach,
+};
+#endif /* CONFIG_CGROUP_PERF */
diff -Nur linux-3.18.12.orig/kernel/exit.c linux-3.18.12/kernel/exit.c
--- linux-3.18.12.orig/kernel/exit.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/exit.c	2015-04-26 13:32:22.431684003 -0500
@@ -147,7 +147,7 @@
 	 * Do this under ->siglock, we can race with another thread
 	 * doing sigqueue_free() if we have SIGQUEUE_PREALLOC signals.
 	 */
-	flush_sigqueue(&tsk->pending);
+	flush_task_sigqueue(tsk);
 	tsk->sighand = NULL;
 	spin_unlock(&sighand->siglock);
 
diff -Nur linux-3.18.12.orig/kernel/fork.c linux-3.18.12/kernel/fork.c
--- linux-3.18.12.orig/kernel/fork.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/fork.c	2015-04-26 13:32:22.435684003 -0500
@@ -97,7 +97,7 @@
 
 DEFINE_PER_CPU(unsigned long, process_counts) = 0;
 
-__cacheline_aligned DEFINE_RWLOCK(tasklist_lock);  /* outer */
+DEFINE_RWLOCK(tasklist_lock);  /* outer */
 
 #ifdef CONFIG_PROVE_RCU
 int lockdep_tasklist_lock_is_held(void)
@@ -233,7 +233,9 @@
 	if (atomic_dec_and_test(&sig->sigcnt))
 		free_signal_struct(sig);
 }
-
+#ifdef CONFIG_PREEMPT_RT_BASE
+static
+#endif
 void __put_task_struct(struct task_struct *tsk)
 {
 	WARN_ON(!tsk->exit_state);
@@ -249,7 +251,18 @@
 	if (!profile_handoff_task(tsk))
 		free_task(tsk);
 }
+#ifndef CONFIG_PREEMPT_RT_BASE
 EXPORT_SYMBOL_GPL(__put_task_struct);
+#else
+void __put_task_struct_cb(struct rcu_head *rhp)
+{
+	struct task_struct *tsk = container_of(rhp, struct task_struct, put_rcu);
+
+	__put_task_struct(tsk);
+
+}
+EXPORT_SYMBOL_GPL(__put_task_struct_cb);
+#endif
 
 void __init __weak arch_task_cache_init(void) { }
 
@@ -643,6 +656,19 @@
 }
 EXPORT_SYMBOL_GPL(__mmdrop);
 
+#ifdef CONFIG_PREEMPT_RT_BASE
+/*
+ * RCU callback for delayed mm drop. Not strictly rcu, but we don't
+ * want another facility to make this work.
+ */
+void __mmdrop_delayed(struct rcu_head *rhp)
+{
+	struct mm_struct *mm = container_of(rhp, struct mm_struct, delayed_drop);
+
+	__mmdrop(mm);
+}
+#endif
+
 /*
  * Decrement the use count and release all resources for an mm.
  */
@@ -1157,6 +1183,9 @@
  */
 static void posix_cpu_timers_init(struct task_struct *tsk)
 {
+#ifdef CONFIG_PREEMPT_RT_BASE
+	tsk->posix_timer_list = NULL;
+#endif
 	tsk->cputime_expires.prof_exp = 0;
 	tsk->cputime_expires.virt_exp = 0;
 	tsk->cputime_expires.sched_exp = 0;
@@ -1284,6 +1313,7 @@
 	spin_lock_init(&p->alloc_lock);
 
 	init_sigpending(&p->pending);
+	p->sigqueue_cache = NULL;
 
 	p->utime = p->stime = p->gtime = 0;
 	p->utimescaled = p->stimescaled = 0;
@@ -1291,7 +1321,8 @@
 	p->prev_cputime.utime = p->prev_cputime.stime = 0;
 #endif
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
-	seqlock_init(&p->vtime_seqlock);
+	raw_spin_lock_init(&p->vtime_lock);
+	seqcount_init(&p->vtime_seq);
 	p->vtime_snap = 0;
 	p->vtime_snap_whence = VTIME_SLEEPING;
 #endif
@@ -1342,6 +1373,9 @@
 	p->hardirq_context = 0;
 	p->softirq_context = 0;
 #endif
+#ifdef CONFIG_PREEMPT_RT_FULL
+	p->pagefault_disabled = 0;
+#endif
 #ifdef CONFIG_LOCKDEP
 	p->lockdep_depth = 0; /* no locks held yet */
 	p->curr_chain_key = 0;
diff -Nur linux-3.18.12.orig/kernel/futex.c linux-3.18.12/kernel/futex.c
--- linux-3.18.12.orig/kernel/futex.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/futex.c	2015-04-26 13:32:22.435684003 -0500
@@ -738,7 +738,9 @@
 		 * task still owns the PI-state:
 		 */
 		if (head->next != next) {
+			raw_spin_unlock_irq(&curr->pi_lock);
 			spin_unlock(&hb->lock);
+			raw_spin_lock_irq(&curr->pi_lock);
 			continue;
 		}
 
@@ -1705,6 +1707,16 @@
 				requeue_pi_wake_futex(this, &key2, hb2);
 				drop_count++;
 				continue;
+			} else if (ret == -EAGAIN) {
+				/*
+				 * Waiter was woken by timeout or
+				 * signal and has set pi_blocked_on to
+				 * PI_WAKEUP_INPROGRESS before we
+				 * tried to enqueue it on the rtmutex.
+				 */
+				this->pi_state = NULL;
+				free_pi_state(pi_state);
+				continue;
 			} else if (ret) {
 				/* -EDEADLK */
 				this->pi_state = NULL;
@@ -2549,7 +2561,7 @@
 	struct hrtimer_sleeper timeout, *to = NULL;
 	struct rt_mutex_waiter rt_waiter;
 	struct rt_mutex *pi_mutex = NULL;
-	struct futex_hash_bucket *hb;
+	struct futex_hash_bucket *hb, *hb2;
 	union futex_key key2 = FUTEX_KEY_INIT;
 	struct futex_q q = futex_q_init;
 	int res, ret;
@@ -2574,10 +2586,7 @@
 	 * The waiter is allocated on our stack, manipulated by the requeue
 	 * code while we sleep on uaddr.
 	 */
-	debug_rt_mutex_init_waiter(&rt_waiter);
-	RB_CLEAR_NODE(&rt_waiter.pi_tree_entry);
-	RB_CLEAR_NODE(&rt_waiter.tree_entry);
-	rt_waiter.task = NULL;
+	rt_mutex_init_waiter(&rt_waiter, false);
 
 	ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2, VERIFY_WRITE);
 	if (unlikely(ret != 0))
@@ -2608,20 +2617,55 @@
 	/* Queue the futex_q, drop the hb lock, wait for wakeup. */
 	futex_wait_queue_me(hb, &q, to);
 
-	spin_lock(&hb->lock);
-	ret = handle_early_requeue_pi_wakeup(hb, &q, &key2, to);
-	spin_unlock(&hb->lock);
-	if (ret)
-		goto out_put_keys;
+	/*
+	 * On RT we must avoid races with requeue and trying to block
+	 * on two mutexes (hb->lock and uaddr2's rtmutex) by
+	 * serializing access to pi_blocked_on with pi_lock.
+	 */
+	raw_spin_lock_irq(&current->pi_lock);
+	if (current->pi_blocked_on) {
+		/*
+		 * We have been requeued or are in the process of
+		 * being requeued.
+		 */
+		raw_spin_unlock_irq(&current->pi_lock);
+	} else {
+		/*
+		 * Setting pi_blocked_on to PI_WAKEUP_INPROGRESS
+		 * prevents a concurrent requeue from moving us to the
+		 * uaddr2 rtmutex. After that we can safely acquire
+		 * (and possibly block on) hb->lock.
+		 */
+		current->pi_blocked_on = PI_WAKEUP_INPROGRESS;
+		raw_spin_unlock_irq(&current->pi_lock);
+
+		spin_lock(&hb->lock);
+
+		/*
+		 * Clean up pi_blocked_on. We might leak it otherwise
+		 * when we succeeded with the hb->lock in the fast
+		 * path.
+		 */
+		raw_spin_lock_irq(&current->pi_lock);
+		current->pi_blocked_on = NULL;
+		raw_spin_unlock_irq(&current->pi_lock);
+
+		ret = handle_early_requeue_pi_wakeup(hb, &q, &key2, to);
+		spin_unlock(&hb->lock);
+		if (ret)
+			goto out_put_keys;
+	}
 
 	/*
-	 * In order for us to be here, we know our q.key == key2, and since
-	 * we took the hb->lock above, we also know that futex_requeue() has
-	 * completed and we no longer have to concern ourselves with a wakeup
-	 * race with the atomic proxy lock acquisition by the requeue code. The
-	 * futex_requeue dropped our key1 reference and incremented our key2
-	 * reference count.
+	 * In order to be here, we have either been requeued, are in
+	 * the process of being requeued, or requeue successfully
+	 * acquired uaddr2 on our behalf.  If pi_blocked_on was
+	 * non-null above, we may be racing with a requeue.  Do not
+	 * rely on q->lock_ptr to be hb2->lock until after blocking on
+	 * hb->lock or hb2->lock. The futex_requeue dropped our key1
+	 * reference and incremented our key2 reference count.
 	 */
+	hb2 = hash_futex(&key2);
 
 	/* Check if the requeue code acquired the second futex for us. */
 	if (!q.rt_waiter) {
@@ -2630,9 +2674,10 @@
 		 * did a lock-steal - fix up the PI-state in that case.
 		 */
 		if (q.pi_state && (q.pi_state->owner != current)) {
-			spin_lock(q.lock_ptr);
+			spin_lock(&hb2->lock);
+			BUG_ON(&hb2->lock != q.lock_ptr);
 			ret = fixup_pi_state_owner(uaddr2, &q, current);
-			spin_unlock(q.lock_ptr);
+			spin_unlock(&hb2->lock);
 		}
 	} else {
 		/*
@@ -2645,7 +2690,8 @@
 		ret = rt_mutex_finish_proxy_lock(pi_mutex, to, &rt_waiter);
 		debug_rt_mutex_free_waiter(&rt_waiter);
 
-		spin_lock(q.lock_ptr);
+		spin_lock(&hb2->lock);
+		BUG_ON(&hb2->lock != q.lock_ptr);
 		/*
 		 * Fixup the pi_state owner and possibly acquire the lock if we
 		 * haven't already.
diff -Nur linux-3.18.12.orig/kernel/irq/handle.c linux-3.18.12/kernel/irq/handle.c
--- linux-3.18.12.orig/kernel/irq/handle.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/irq/handle.c	2015-04-26 13:32:22.435684003 -0500
@@ -133,6 +133,8 @@
 irqreturn_t
 handle_irq_event_percpu(struct irq_desc *desc, struct irqaction *action)
 {
+	struct pt_regs *regs = get_irq_regs();
+	u64 ip = regs ? instruction_pointer(regs) : 0;
 	irqreturn_t retval = IRQ_NONE;
 	unsigned int flags = 0, irq = desc->irq_data.irq;
 
@@ -173,7 +175,11 @@
 		action = action->next;
 	} while (action);
 
-	add_interrupt_randomness(irq, flags);
+#ifndef CONFIG_PREEMPT_RT_FULL
+	add_interrupt_randomness(irq, flags, ip);
+#else
+	desc->random_ip = ip;
+#endif
 
 	if (!noirqdebug)
 		note_interrupt(irq, desc, retval);
diff -Nur linux-3.18.12.orig/kernel/irq/manage.c linux-3.18.12/kernel/irq/manage.c
--- linux-3.18.12.orig/kernel/irq/manage.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/irq/manage.c	2015-04-26 13:32:22.435684003 -0500
@@ -22,6 +22,7 @@
 #include "internals.h"
 
 #ifdef CONFIG_IRQ_FORCED_THREADING
+# ifndef CONFIG_PREEMPT_RT_BASE
 __read_mostly bool force_irqthreads;
 
 static int __init setup_forced_irqthreads(char *arg)
@@ -30,6 +31,7 @@
 	return 0;
 }
 early_param("threadirqs", setup_forced_irqthreads);
+# endif
 #endif
 
 static void __synchronize_hardirq(struct irq_desc *desc)
@@ -173,6 +175,62 @@
 irq_get_pending(struct cpumask *mask, struct irq_desc *desc) { }
 #endif
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+static void _irq_affinity_notify(struct irq_affinity_notify *notify);
+static struct task_struct *set_affinity_helper;
+static LIST_HEAD(affinity_list);
+static DEFINE_RAW_SPINLOCK(affinity_list_lock);
+
+static int set_affinity_thread(void *unused)
+{
+	while (1) {
+		struct irq_affinity_notify *notify;
+		int empty;
+
+		set_current_state(TASK_INTERRUPTIBLE);
+
+		raw_spin_lock_irq(&affinity_list_lock);
+		empty = list_empty(&affinity_list);
+		raw_spin_unlock_irq(&affinity_list_lock);
+
+		if (empty)
+			schedule();
+		if (kthread_should_stop())
+			break;
+		set_current_state(TASK_RUNNING);
+try_next:
+		notify = NULL;
+
+		raw_spin_lock_irq(&affinity_list_lock);
+		if (!list_empty(&affinity_list)) {
+			notify = list_first_entry(&affinity_list,
+					struct irq_affinity_notify, list);
+			list_del_init(&notify->list);
+		}
+		raw_spin_unlock_irq(&affinity_list_lock);
+
+		if (!notify)
+			continue;
+		_irq_affinity_notify(notify);
+		goto try_next;
+	}
+	return 0;
+}
+
+static void init_helper_thread(void)
+{
+	if (set_affinity_helper)
+		return;
+	set_affinity_helper = kthread_run(set_affinity_thread, NULL,
+			"affinity-cb");
+	WARN_ON(IS_ERR(set_affinity_helper));
+}
+#else
+
+static inline void init_helper_thread(void) { }
+
+#endif
+
 int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
 			bool force)
 {
@@ -211,7 +269,17 @@
 
 	if (desc->affinity_notify) {
 		kref_get(&desc->affinity_notify->kref);
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+		raw_spin_lock(&affinity_list_lock);
+		if (list_empty(&desc->affinity_notify->list))
+			list_add_tail(&affinity_list,
+					&desc->affinity_notify->list);
+		raw_spin_unlock(&affinity_list_lock);
+		wake_up_process(set_affinity_helper);
+#else
 		schedule_work(&desc->affinity_notify->work);
+#endif
 	}
 	irqd_set(data, IRQD_AFFINITY_SET);
 
@@ -246,10 +314,8 @@
 }
 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
 
-static void irq_affinity_notify(struct work_struct *work)
+static void _irq_affinity_notify(struct irq_affinity_notify *notify)
 {
-	struct irq_affinity_notify *notify =
-		container_of(work, struct irq_affinity_notify, work);
 	struct irq_desc *desc = irq_to_desc(notify->irq);
 	cpumask_var_t cpumask;
 	unsigned long flags;
@@ -271,6 +337,13 @@
 	kref_put(&notify->kref, notify->release);
 }
 
+static void irq_affinity_notify(struct work_struct *work)
+{
+	struct irq_affinity_notify *notify =
+		container_of(work, struct irq_affinity_notify, work);
+	_irq_affinity_notify(notify);
+}
+
 /**
  *	irq_set_affinity_notifier - control notification of IRQ affinity changes
  *	@irq:		Interrupt for which to enable/disable notification
@@ -300,6 +373,8 @@
 		notify->irq = irq;
 		kref_init(&notify->kref);
 		INIT_WORK(&notify->work, irq_affinity_notify);
+		INIT_LIST_HEAD(&notify->list);
+		init_helper_thread();
 	}
 
 	raw_spin_lock_irqsave(&desc->lock, flags);
@@ -788,7 +863,15 @@
 	local_bh_disable();
 	ret = action->thread_fn(action->irq, action->dev_id);
 	irq_finalize_oneshot(desc, action);
-	local_bh_enable();
+	/*
+	 * Interrupts which have real time requirements can be set up
+	 * to avoid softirq processing in the thread handler. This is
+	 * safe as these interrupts do not raise soft interrupts.
+	 */
+	if (irq_settings_no_softirq_call(desc))
+		_local_bh_enable();
+	else
+		local_bh_enable();
 	return ret;
 }
 
@@ -871,6 +954,12 @@
 		if (action_ret == IRQ_HANDLED)
 			atomic_inc(&desc->threads_handled);
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+		migrate_disable();
+		add_interrupt_randomness(action->irq, 0,
+				 desc->random_ip ^ (unsigned long) action);
+		migrate_enable();
+#endif
 		wake_threads_waitq(desc);
 	}
 
@@ -1184,6 +1273,9 @@
 			irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
 		}
 
+		if (new->flags & IRQF_NO_SOFTIRQ_CALL)
+			irq_settings_set_no_softirq_call(desc);
+
 		/* Set default affinity mask once everything is setup */
 		setup_affinity(irq, desc, mask);
 
diff -Nur linux-3.18.12.orig/kernel/irq/settings.h linux-3.18.12/kernel/irq/settings.h
--- linux-3.18.12.orig/kernel/irq/settings.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/irq/settings.h	2015-04-26 13:32:22.435684003 -0500
@@ -15,6 +15,7 @@
 	_IRQ_NESTED_THREAD	= IRQ_NESTED_THREAD,
 	_IRQ_PER_CPU_DEVID	= IRQ_PER_CPU_DEVID,
 	_IRQ_IS_POLLED		= IRQ_IS_POLLED,
+	_IRQ_NO_SOFTIRQ_CALL	= IRQ_NO_SOFTIRQ_CALL,
 	_IRQF_MODIFY_MASK	= IRQF_MODIFY_MASK,
 };
 
@@ -28,6 +29,7 @@
 #define IRQ_NESTED_THREAD	GOT_YOU_MORON
 #define IRQ_PER_CPU_DEVID	GOT_YOU_MORON
 #define IRQ_IS_POLLED		GOT_YOU_MORON
+#define IRQ_NO_SOFTIRQ_CALL	GOT_YOU_MORON
 #undef IRQF_MODIFY_MASK
 #define IRQF_MODIFY_MASK	GOT_YOU_MORON
 
@@ -38,6 +40,16 @@
 	desc->status_use_accessors |= (set & _IRQF_MODIFY_MASK);
 }
 
+static inline bool irq_settings_no_softirq_call(struct irq_desc *desc)
+{
+	return desc->status_use_accessors & _IRQ_NO_SOFTIRQ_CALL;
+}
+
+static inline void irq_settings_set_no_softirq_call(struct irq_desc *desc)
+{
+	desc->status_use_accessors |= _IRQ_NO_SOFTIRQ_CALL;
+}
+
 static inline bool irq_settings_is_per_cpu(struct irq_desc *desc)
 {
 	return desc->status_use_accessors & _IRQ_PER_CPU;
diff -Nur linux-3.18.12.orig/kernel/irq/spurious.c linux-3.18.12/kernel/irq/spurious.c
--- linux-3.18.12.orig/kernel/irq/spurious.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/irq/spurious.c	2015-04-26 13:32:22.435684003 -0500
@@ -444,6 +444,10 @@
 
 static int __init irqfixup_setup(char *str)
 {
+#ifdef CONFIG_PREEMPT_RT_BASE
+	pr_warn("irqfixup boot option not supported w/ CONFIG_PREEMPT_RT_BASE\n");
+	return 1;
+#endif
 	irqfixup = 1;
 	printk(KERN_WARNING "Misrouted IRQ fixup support enabled.\n");
 	printk(KERN_WARNING "This may impact system performance.\n");
@@ -456,6 +460,10 @@
 
 static int __init irqpoll_setup(char *str)
 {
+#ifdef CONFIG_PREEMPT_RT_BASE
+	pr_warn("irqpoll boot option not supported w/ CONFIG_PREEMPT_RT_BASE\n");
+	return 1;
+#endif
 	irqfixup = 2;
 	printk(KERN_WARNING "Misrouted IRQ fixup and polling support "
 				"enabled\n");
diff -Nur linux-3.18.12.orig/kernel/irq_work.c linux-3.18.12/kernel/irq_work.c
--- linux-3.18.12.orig/kernel/irq_work.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/irq_work.c	2015-04-26 13:32:22.435684003 -0500
@@ -17,12 +17,15 @@
 #include <linux/cpu.h>
 #include <linux/notifier.h>
 #include <linux/smp.h>
+#include <linux/interrupt.h>
 #include <asm/processor.h>
 
 
 static DEFINE_PER_CPU(struct llist_head, raised_list);
 static DEFINE_PER_CPU(struct llist_head, lazy_list);
-
+#ifdef CONFIG_PREEMPT_RT_FULL
+static DEFINE_PER_CPU(struct llist_head, hirq_work_list);
+#endif
 /*
  * Claim the entry so that no one else will poke at it.
  */
@@ -65,6 +68,8 @@
  */
 bool irq_work_queue_on(struct irq_work *work, int cpu)
 {
+	bool raise_irqwork;
+
 	/* All work should have been flushed before going offline */
 	WARN_ON_ONCE(cpu_is_offline(cpu));
 
@@ -75,7 +80,19 @@
 	if (!irq_work_claim(work))
 		return false;
 
-	if (llist_add(&work->llnode, &per_cpu(raised_list, cpu)))
+#ifdef CONFIG_PREEMPT_RT_FULL
+	if (work->flags & IRQ_WORK_HARD_IRQ)
+		raise_irqwork = llist_add(&work->llnode,
+					  &per_cpu(hirq_work_list, cpu));
+	else
+		raise_irqwork = llist_add(&work->llnode,
+					  &per_cpu(lazy_list, cpu));
+#else
+		raise_irqwork = llist_add(&work->llnode,
+					  &per_cpu(raised_list, cpu));
+#endif
+
+	if (raise_irqwork)
 		arch_send_call_function_single_ipi(cpu);
 
 	return true;
@@ -93,7 +110,16 @@
 	/* Queue the entry and raise the IPI if needed. */
 	preempt_disable();
 
-	/* If the work is "lazy", handle it from next tick if any */
+#ifdef CONFIG_PREEMPT_RT_FULL
+	if (work->flags & IRQ_WORK_HARD_IRQ) {
+		if (llist_add(&work->llnode, this_cpu_ptr(&hirq_work_list)))
+			arch_irq_work_raise();
+	} else {
+		if (llist_add(&work->llnode, this_cpu_ptr(&lazy_list)) &&
+		    tick_nohz_tick_stopped())
+			raise_softirq(TIMER_SOFTIRQ);
+	}
+#else
 	if (work->flags & IRQ_WORK_LAZY) {
 		if (llist_add(&work->llnode, this_cpu_ptr(&lazy_list)) &&
 		    tick_nohz_tick_stopped())
@@ -102,6 +128,7 @@
 		if (llist_add(&work->llnode, this_cpu_ptr(&raised_list)))
 			arch_irq_work_raise();
 	}
+#endif
 
 	preempt_enable();
 
@@ -116,9 +143,12 @@
 	raised = this_cpu_ptr(&raised_list);
 	lazy = this_cpu_ptr(&lazy_list);
 
-	if (llist_empty(raised) || arch_irq_work_has_interrupt())
+	if (llist_empty(raised))
 		if (llist_empty(lazy))
-			return false;
+#ifdef CONFIG_PREEMPT_RT_FULL
+			if (llist_empty(this_cpu_ptr(&hirq_work_list)))
+#endif
+				return false;
 
 	/* All work should have been flushed before going offline */
 	WARN_ON_ONCE(cpu_is_offline(smp_processor_id()));
@@ -132,7 +162,9 @@
 	struct irq_work *work;
 	struct llist_node *llnode;
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 	BUG_ON(!irqs_disabled());
+#endif
 
 	if (llist_empty(list))
 		return;
@@ -168,18 +200,26 @@
  */
 void irq_work_run(void)
 {
+#ifdef CONFIG_PREEMPT_RT_FULL
+	irq_work_run_list(this_cpu_ptr(&hirq_work_list));
+#else
 	irq_work_run_list(this_cpu_ptr(&raised_list));
 	irq_work_run_list(this_cpu_ptr(&lazy_list));
+#endif
 }
 EXPORT_SYMBOL_GPL(irq_work_run);
 
 void irq_work_tick(void)
 {
+#ifdef CONFIG_PREEMPT_RT_FULL
+	irq_work_run_list(this_cpu_ptr(&lazy_list));
+#else
 	struct llist_head *raised = &__get_cpu_var(raised_list);
 
 	if (!llist_empty(raised) && !arch_irq_work_has_interrupt())
 		irq_work_run_list(raised);
 	irq_work_run_list(&__get_cpu_var(lazy_list));
+#endif
 }
 
 /*
diff -Nur linux-3.18.12.orig/kernel/Kconfig.locks linux-3.18.12/kernel/Kconfig.locks
--- linux-3.18.12.orig/kernel/Kconfig.locks	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/Kconfig.locks	2015-04-26 13:32:22.431684003 -0500
@@ -225,11 +225,11 @@
 
 config MUTEX_SPIN_ON_OWNER
 	def_bool y
-	depends on SMP && !DEBUG_MUTEXES && ARCH_SUPPORTS_ATOMIC_RMW
+	depends on SMP && !DEBUG_MUTEXES && ARCH_SUPPORTS_ATOMIC_RMW && !PREEMPT_RT_FULL
 
 config RWSEM_SPIN_ON_OWNER
        def_bool y
-       depends on SMP && RWSEM_XCHGADD_ALGORITHM && ARCH_SUPPORTS_ATOMIC_RMW
+       depends on SMP && RWSEM_XCHGADD_ALGORITHM && ARCH_SUPPORTS_ATOMIC_RMW && !PREEMPT_RT_FULL
 
 config ARCH_USE_QUEUE_RWLOCK
 	bool
diff -Nur linux-3.18.12.orig/kernel/Kconfig.preempt linux-3.18.12/kernel/Kconfig.preempt
--- linux-3.18.12.orig/kernel/Kconfig.preempt	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/Kconfig.preempt	2015-04-26 13:32:22.431684003 -0500
@@ -1,3 +1,16 @@
+config PREEMPT
+	bool
+	select PREEMPT_COUNT
+
+config PREEMPT_RT_BASE
+	bool
+	select PREEMPT
+
+config HAVE_PREEMPT_LAZY
+	bool
+
+config PREEMPT_LAZY
+	def_bool y if HAVE_PREEMPT_LAZY && PREEMPT_RT_FULL
 
 choice
 	prompt "Preemption Model"
@@ -33,9 +46,9 @@
 
 	  Select this if you are building a kernel for a desktop system.
 
-config PREEMPT
+config PREEMPT__LL
 	bool "Preemptible Kernel (Low-Latency Desktop)"
-	select PREEMPT_COUNT
+	select PREEMPT
 	select UNINLINE_SPIN_UNLOCK if !ARCH_INLINE_SPIN_UNLOCK
 	help
 	  This option reduces the latency of the kernel by making
@@ -52,6 +65,22 @@
 	  embedded system with latency requirements in the milliseconds
 	  range.
 
+config PREEMPT_RTB
+	bool "Preemptible Kernel (Basic RT)"
+	select PREEMPT_RT_BASE
+	help
+	  This option is basically the same as (Low-Latency Desktop) but
+	  enables changes which are preliminary for the full preemptible
+	  RT kernel.
+
+config PREEMPT_RT_FULL
+	bool "Fully Preemptible Kernel (RT)"
+	depends on IRQ_FORCED_THREADING
+	select PREEMPT_RT_BASE
+	select PREEMPT_RCU
+	help
+	  All and everything
+
 endchoice
 
 config PREEMPT_COUNT
diff -Nur linux-3.18.12.orig/kernel/ksysfs.c linux-3.18.12/kernel/ksysfs.c
--- linux-3.18.12.orig/kernel/ksysfs.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/ksysfs.c	2015-04-26 13:32:22.435684003 -0500
@@ -136,6 +136,15 @@
 
 #endif /* CONFIG_KEXEC */
 
+#if defined(CONFIG_PREEMPT_RT_FULL)
+static ssize_t  realtime_show(struct kobject *kobj,
+			      struct kobj_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%d\n", 1);
+}
+KERNEL_ATTR_RO(realtime);
+#endif
+
 /* whether file capabilities are enabled */
 static ssize_t fscaps_show(struct kobject *kobj,
 				  struct kobj_attribute *attr, char *buf)
@@ -203,6 +212,9 @@
 	&vmcoreinfo_attr.attr,
 #endif
 	&rcu_expedited_attr.attr,
+#ifdef CONFIG_PREEMPT_RT_FULL
+	&realtime_attr.attr,
+#endif
 	NULL
 };
 
diff -Nur linux-3.18.12.orig/kernel/locking/lglock.c linux-3.18.12/kernel/locking/lglock.c
--- linux-3.18.12.orig/kernel/locking/lglock.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/locking/lglock.c	2015-04-26 13:32:22.435684003 -0500
@@ -4,6 +4,15 @@
 #include <linux/cpu.h>
 #include <linux/string.h>
 
+#ifndef CONFIG_PREEMPT_RT_FULL
+# define lg_lock_ptr		arch_spinlock_t
+# define lg_do_lock(l)		arch_spin_lock(l)
+# define lg_do_unlock(l)	arch_spin_unlock(l)
+#else
+# define lg_lock_ptr		struct rt_mutex
+# define lg_do_lock(l)		__rt_spin_lock(l)
+# define lg_do_unlock(l)	__rt_spin_unlock(l)
+#endif
 /*
  * Note there is no uninit, so lglocks cannot be defined in
  * modules (but it's fine to use them from there)
@@ -12,51 +21,60 @@
 
 void lg_lock_init(struct lglock *lg, char *name)
 {
+#ifdef CONFIG_PREEMPT_RT_FULL
+	int i;
+
+	for_each_possible_cpu(i) {
+		struct rt_mutex *lock = per_cpu_ptr(lg->lock, i);
+
+		rt_mutex_init(lock);
+	}
+#endif
 	LOCKDEP_INIT_MAP(&lg->lock_dep_map, name, &lg->lock_key, 0);
 }
 EXPORT_SYMBOL(lg_lock_init);
 
 void lg_local_lock(struct lglock *lg)
 {
-	arch_spinlock_t *lock;
+	lg_lock_ptr *lock;
 
-	preempt_disable();
+	migrate_disable();
 	lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
 	lock = this_cpu_ptr(lg->lock);
-	arch_spin_lock(lock);
+	lg_do_lock(lock);
 }
 EXPORT_SYMBOL(lg_local_lock);
 
 void lg_local_unlock(struct lglock *lg)
 {
-	arch_spinlock_t *lock;
+	lg_lock_ptr *lock;
 
 	lock_release(&lg->lock_dep_map, 1, _RET_IP_);
 	lock = this_cpu_ptr(lg->lock);
-	arch_spin_unlock(lock);
-	preempt_enable();
+	lg_do_unlock(lock);
+	migrate_enable();
 }
 EXPORT_SYMBOL(lg_local_unlock);
 
 void lg_local_lock_cpu(struct lglock *lg, int cpu)
 {
-	arch_spinlock_t *lock;
+	lg_lock_ptr *lock;
 
-	preempt_disable();
+	preempt_disable_nort();
 	lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
 	lock = per_cpu_ptr(lg->lock, cpu);
-	arch_spin_lock(lock);
+	lg_do_lock(lock);
 }
 EXPORT_SYMBOL(lg_local_lock_cpu);
 
 void lg_local_unlock_cpu(struct lglock *lg, int cpu)
 {
-	arch_spinlock_t *lock;
+	lg_lock_ptr *lock;
 
 	lock_release(&lg->lock_dep_map, 1, _RET_IP_);
 	lock = per_cpu_ptr(lg->lock, cpu);
-	arch_spin_unlock(lock);
-	preempt_enable();
+	lg_do_unlock(lock);
+	preempt_enable_nort();
 }
 EXPORT_SYMBOL(lg_local_unlock_cpu);
 
@@ -64,12 +82,12 @@
 {
 	int i;
 
-	preempt_disable();
+	preempt_disable_nort();
 	lock_acquire_exclusive(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
 	for_each_possible_cpu(i) {
-		arch_spinlock_t *lock;
+		lg_lock_ptr *lock;
 		lock = per_cpu_ptr(lg->lock, i);
-		arch_spin_lock(lock);
+		lg_do_lock(lock);
 	}
 }
 EXPORT_SYMBOL(lg_global_lock);
@@ -80,10 +98,35 @@
 
 	lock_release(&lg->lock_dep_map, 1, _RET_IP_);
 	for_each_possible_cpu(i) {
-		arch_spinlock_t *lock;
+		lg_lock_ptr *lock;
 		lock = per_cpu_ptr(lg->lock, i);
-		arch_spin_unlock(lock);
+		lg_do_unlock(lock);
 	}
-	preempt_enable();
+	preempt_enable_nort();
 }
 EXPORT_SYMBOL(lg_global_unlock);
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * HACK: If you use this, you get to keep the pieces.
+ * Used in queue_stop_cpus_work() when stop machinery
+ * is called from inactive CPU, so we can't schedule.
+ */
+# define lg_do_trylock_relax(l)			\
+	do {					\
+		while (!__rt_spin_trylock(l))	\
+			cpu_relax();		\
+	} while (0)
+
+void lg_global_trylock_relax(struct lglock *lg)
+{
+	int i;
+
+	lock_acquire_exclusive(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
+	for_each_possible_cpu(i) {
+		lg_lock_ptr *lock;
+		lock = per_cpu_ptr(lg->lock, i);
+		lg_do_trylock_relax(lock);
+	}
+}
+#endif
diff -Nur linux-3.18.12.orig/kernel/locking/lockdep.c linux-3.18.12/kernel/locking/lockdep.c
--- linux-3.18.12.orig/kernel/locking/lockdep.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/locking/lockdep.c	2015-04-26 13:32:22.435684003 -0500
@@ -3542,6 +3542,7 @@
 		}
 	}
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 	/*
 	 * We dont accurately track softirq state in e.g.
 	 * hardirq contexts (such as on 4KSTACKS), so only
@@ -3556,6 +3557,7 @@
 			DEBUG_LOCKS_WARN_ON(!current->softirqs_enabled);
 		}
 	}
+#endif
 
 	if (!debug_locks)
 		print_irqtrace_events(current);
diff -Nur linux-3.18.12.orig/kernel/locking/Makefile linux-3.18.12/kernel/locking/Makefile
--- linux-3.18.12.orig/kernel/locking/Makefile	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/locking/Makefile	2015-04-26 13:32:22.435684003 -0500
@@ -1,5 +1,5 @@
 
-obj-y += mutex.o semaphore.o rwsem.o mcs_spinlock.o
+obj-y += semaphore.o mcs_spinlock.o
 
 ifdef CONFIG_FUNCTION_TRACER
 CFLAGS_REMOVE_lockdep.o = -pg
@@ -8,7 +8,11 @@
 CFLAGS_REMOVE_rtmutex-debug.o = -pg
 endif
 
+ifneq ($(CONFIG_PREEMPT_RT_FULL),y)
+obj-y += mutex.o
 obj-$(CONFIG_DEBUG_MUTEXES) += mutex-debug.o
+obj-y += rwsem.o
+endif
 obj-$(CONFIG_LOCKDEP) += lockdep.o
 ifeq ($(CONFIG_PROC_FS),y)
 obj-$(CONFIG_LOCKDEP) += lockdep_proc.o
@@ -21,8 +25,11 @@
 obj-$(CONFIG_RT_MUTEX_TESTER) += rtmutex-tester.o
 obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o
 obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock_debug.o
+ifneq ($(CONFIG_PREEMPT_RT_FULL),y)
 obj-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o
 obj-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem-xadd.o
+endif
 obj-$(CONFIG_PERCPU_RWSEM) += percpu-rwsem.o
+obj-$(CONFIG_PREEMPT_RT_FULL) += rt.o
 obj-$(CONFIG_QUEUE_RWLOCK) += qrwlock.o
 obj-$(CONFIG_LOCK_TORTURE_TEST) += locktorture.o
diff -Nur linux-3.18.12.orig/kernel/locking/percpu-rwsem.c linux-3.18.12/kernel/locking/percpu-rwsem.c
--- linux-3.18.12.orig/kernel/locking/percpu-rwsem.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/locking/percpu-rwsem.c	2015-04-26 13:32:22.435684003 -0500
@@ -84,8 +84,12 @@
 
 	down_read(&brw->rw_sem);
 	atomic_inc(&brw->slow_read_ctr);
+#ifdef CONFIG_PREEMPT_RT_FULL
+	up_read(&brw->rw_sem);
+#else
 	/* avoid up_read()->rwsem_release() */
 	__up_read(&brw->rw_sem);
+#endif
 }
 
 void percpu_up_read(struct percpu_rw_semaphore *brw)
diff -Nur linux-3.18.12.orig/kernel/locking/rt.c linux-3.18.12/kernel/locking/rt.c
--- linux-3.18.12.orig/kernel/locking/rt.c	1969-12-31 18:00:00.000000000 -0600
+++ linux-3.18.12/kernel/locking/rt.c	2015-04-26 13:32:22.435684003 -0500
@@ -0,0 +1,456 @@
+/*
+ * kernel/rt.c
+ *
+ * Real-Time Preemption Support
+ *
+ * started by Ingo Molnar:
+ *
+ *  Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ *  Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
+ *
+ * historic credit for proving that Linux spinlocks can be implemented via
+ * RT-aware mutexes goes to many people: The Pmutex project (Dirk Grambow
+ * and others) who prototyped it on 2.4 and did lots of comparative
+ * research and analysis; TimeSys, for proving that you can implement a
+ * fully preemptible kernel via the use of IRQ threading and mutexes;
+ * Bill Huey for persuasively arguing on lkml that the mutex model is the
+ * right one; and to MontaVista, who ported pmutexes to 2.6.
+ *
+ * This code is a from-scratch implementation and is not based on pmutexes,
+ * but the idea of converting spinlocks to mutexes is used here too.
+ *
+ * lock debugging, locking tree, deadlock detection:
+ *
+ *  Copyright (C) 2004, LynuxWorks, Inc., Igor Manyilov, Bill Huey
+ *  Released under the General Public License (GPL).
+ *
+ * Includes portions of the generic R/W semaphore implementation from:
+ *
+ *  Copyright (c) 2001   David Howells (dhowells@redhat.com).
+ *  - Derived partially from idea by Andrea Arcangeli <andrea@suse.de>
+ *  - Derived also from comments by Linus
+ *
+ * Pending ownership of locks and ownership stealing:
+ *
+ *  Copyright (C) 2005, Kihon Technologies Inc., Steven Rostedt
+ *
+ *   (also by Steven Rostedt)
+ *    - Converted single pi_lock to individual task locks.
+ *
+ * By Esben Nielsen:
+ *    Doing priority inheritance with help of the scheduler.
+ *
+ *  Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
+ *  - major rework based on Esben Nielsens initial patch
+ *  - replaced thread_info references by task_struct refs
+ *  - removed task->pending_owner dependency
+ *  - BKL drop/reacquire for semaphore style locks to avoid deadlocks
+ *    in the scheduler return path as discussed with Steven Rostedt
+ *
+ *  Copyright (C) 2006, Kihon Technologies Inc.
+ *    Steven Rostedt <rostedt@goodmis.org>
+ *  - debugged and patched Thomas Gleixner's rework.
+ *  - added back the cmpxchg to the rework.
+ *  - turned atomic require back on for SMP.
+ */
+
+#include <linux/spinlock.h>
+#include <linux/rtmutex.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <linux/syscalls.h>
+#include <linux/interrupt.h>
+#include <linux/plist.h>
+#include <linux/fs.h>
+#include <linux/futex.h>
+#include <linux/hrtimer.h>
+
+#include "rtmutex_common.h"
+
+/*
+ * struct mutex functions
+ */
+void __mutex_do_init(struct mutex *mutex, const char *name,
+		     struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	/*
+	 * Make sure we are not reinitializing a held lock:
+	 */
+	debug_check_no_locks_freed((void *)mutex, sizeof(*mutex));
+	lockdep_init_map(&mutex->dep_map, name, key, 0);
+#endif
+	mutex->lock.save_state = 0;
+}
+EXPORT_SYMBOL(__mutex_do_init);
+
+void __lockfunc _mutex_lock(struct mutex *lock)
+{
+	mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+	rt_mutex_lock(&lock->lock);
+}
+EXPORT_SYMBOL(_mutex_lock);
+
+int __lockfunc _mutex_lock_interruptible(struct mutex *lock)
+{
+	int ret;
+
+	mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+	ret = rt_mutex_lock_interruptible(&lock->lock);
+	if (ret)
+		mutex_release(&lock->dep_map, 1, _RET_IP_);
+	return ret;
+}
+EXPORT_SYMBOL(_mutex_lock_interruptible);
+
+int __lockfunc _mutex_lock_killable(struct mutex *lock)
+{
+	int ret;
+
+	mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+	ret = rt_mutex_lock_killable(&lock->lock);
+	if (ret)
+		mutex_release(&lock->dep_map, 1, _RET_IP_);
+	return ret;
+}
+EXPORT_SYMBOL(_mutex_lock_killable);
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+void __lockfunc _mutex_lock_nested(struct mutex *lock, int subclass)
+{
+	mutex_acquire_nest(&lock->dep_map, subclass, 0, NULL, _RET_IP_);
+	rt_mutex_lock(&lock->lock);
+}
+EXPORT_SYMBOL(_mutex_lock_nested);
+
+void __lockfunc _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest)
+{
+	mutex_acquire_nest(&lock->dep_map, 0, 0, nest, _RET_IP_);
+	rt_mutex_lock(&lock->lock);
+}
+EXPORT_SYMBOL(_mutex_lock_nest_lock);
+
+int __lockfunc _mutex_lock_interruptible_nested(struct mutex *lock, int subclass)
+{
+	int ret;
+
+	mutex_acquire_nest(&lock->dep_map, subclass, 0, NULL, _RET_IP_);
+	ret = rt_mutex_lock_interruptible(&lock->lock);
+	if (ret)
+		mutex_release(&lock->dep_map, 1, _RET_IP_);
+	return ret;
+}
+EXPORT_SYMBOL(_mutex_lock_interruptible_nested);
+
+int __lockfunc _mutex_lock_killable_nested(struct mutex *lock, int subclass)
+{
+	int ret;
+
+	mutex_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
+	ret = rt_mutex_lock_killable(&lock->lock);
+	if (ret)
+		mutex_release(&lock->dep_map, 1, _RET_IP_);
+	return ret;
+}
+EXPORT_SYMBOL(_mutex_lock_killable_nested);
+#endif
+
+int __lockfunc _mutex_trylock(struct mutex *lock)
+{
+	int ret = rt_mutex_trylock(&lock->lock);
+
+	if (ret)
+		mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+
+	return ret;
+}
+EXPORT_SYMBOL(_mutex_trylock);
+
+void __lockfunc _mutex_unlock(struct mutex *lock)
+{
+	mutex_release(&lock->dep_map, 1, _RET_IP_);
+	rt_mutex_unlock(&lock->lock);
+}
+EXPORT_SYMBOL(_mutex_unlock);
+
+/*
+ * rwlock_t functions
+ */
+int __lockfunc rt_write_trylock(rwlock_t *rwlock)
+{
+	int ret;
+
+	migrate_disable();
+	ret = rt_mutex_trylock(&rwlock->lock);
+	if (ret)
+		rwlock_acquire(&rwlock->dep_map, 0, 1, _RET_IP_);
+	else
+		migrate_enable();
+
+	return ret;
+}
+EXPORT_SYMBOL(rt_write_trylock);
+
+int __lockfunc rt_write_trylock_irqsave(rwlock_t *rwlock, unsigned long *flags)
+{
+	int ret;
+
+	*flags = 0;
+	ret = rt_write_trylock(rwlock);
+	return ret;
+}
+EXPORT_SYMBOL(rt_write_trylock_irqsave);
+
+int __lockfunc rt_read_trylock(rwlock_t *rwlock)
+{
+	struct rt_mutex *lock = &rwlock->lock;
+	int ret = 1;
+
+	/*
+	 * recursive read locks succeed when current owns the lock,
+	 * but not when read_depth == 0 which means that the lock is
+	 * write locked.
+	 */
+	if (rt_mutex_owner(lock) != current) {
+		migrate_disable();
+		ret = rt_mutex_trylock(lock);
+		if (ret)
+			rwlock_acquire(&rwlock->dep_map, 0, 1, _RET_IP_);
+		else
+			migrate_enable();
+
+	} else if (!rwlock->read_depth) {
+		ret = 0;
+	}
+
+	if (ret)
+		rwlock->read_depth++;
+
+	return ret;
+}
+EXPORT_SYMBOL(rt_read_trylock);
+
+void __lockfunc rt_write_lock(rwlock_t *rwlock)
+{
+	rwlock_acquire(&rwlock->dep_map, 0, 0, _RET_IP_);
+	migrate_disable();
+	__rt_spin_lock(&rwlock->lock);
+}
+EXPORT_SYMBOL(rt_write_lock);
+
+void __lockfunc rt_read_lock(rwlock_t *rwlock)
+{
+	struct rt_mutex *lock = &rwlock->lock;
+
+
+	/*
+	 * recursive read locks succeed when current owns the lock
+	 */
+	if (rt_mutex_owner(lock) != current) {
+		migrate_disable();
+		rwlock_acquire(&rwlock->dep_map, 0, 0, _RET_IP_);
+		__rt_spin_lock(lock);
+	}
+	rwlock->read_depth++;
+}
+
+EXPORT_SYMBOL(rt_read_lock);
+
+void __lockfunc rt_write_unlock(rwlock_t *rwlock)
+{
+	/* NOTE: we always pass in '1' for nested, for simplicity */
+	rwlock_release(&rwlock->dep_map, 1, _RET_IP_);
+	__rt_spin_unlock(&rwlock->lock);
+	migrate_enable();
+}
+EXPORT_SYMBOL(rt_write_unlock);
+
+void __lockfunc rt_read_unlock(rwlock_t *rwlock)
+{
+	/* Release the lock only when read_depth is down to 0 */
+	if (--rwlock->read_depth == 0) {
+		rwlock_release(&rwlock->dep_map, 1, _RET_IP_);
+		__rt_spin_unlock(&rwlock->lock);
+		migrate_enable();
+	}
+}
+EXPORT_SYMBOL(rt_read_unlock);
+
+unsigned long __lockfunc rt_write_lock_irqsave(rwlock_t *rwlock)
+{
+	rt_write_lock(rwlock);
+
+	return 0;
+}
+EXPORT_SYMBOL(rt_write_lock_irqsave);
+
+unsigned long __lockfunc rt_read_lock_irqsave(rwlock_t *rwlock)
+{
+	rt_read_lock(rwlock);
+
+	return 0;
+}
+EXPORT_SYMBOL(rt_read_lock_irqsave);
+
+void __rt_rwlock_init(rwlock_t *rwlock, char *name, struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	/*
+	 * Make sure we are not reinitializing a held lock:
+	 */
+	debug_check_no_locks_freed((void *)rwlock, sizeof(*rwlock));
+	lockdep_init_map(&rwlock->dep_map, name, key, 0);
+#endif
+	rwlock->lock.save_state = 1;
+	rwlock->read_depth = 0;
+}
+EXPORT_SYMBOL(__rt_rwlock_init);
+
+/*
+ * rw_semaphores
+ */
+
+void  rt_up_write(struct rw_semaphore *rwsem)
+{
+	rwsem_release(&rwsem->dep_map, 1, _RET_IP_);
+	rt_mutex_unlock(&rwsem->lock);
+}
+EXPORT_SYMBOL(rt_up_write);
+
+void  rt_up_read(struct rw_semaphore *rwsem)
+{
+	rwsem_release(&rwsem->dep_map, 1, _RET_IP_);
+	if (--rwsem->read_depth == 0)
+		rt_mutex_unlock(&rwsem->lock);
+}
+EXPORT_SYMBOL(rt_up_read);
+
+/*
+ * downgrade a write lock into a read lock
+ * - just wake up any readers at the front of the queue
+ */
+void  rt_downgrade_write(struct rw_semaphore *rwsem)
+{
+	BUG_ON(rt_mutex_owner(&rwsem->lock) != current);
+	rwsem->read_depth = 1;
+}
+EXPORT_SYMBOL(rt_downgrade_write);
+
+int  rt_down_write_trylock(struct rw_semaphore *rwsem)
+{
+	int ret = rt_mutex_trylock(&rwsem->lock);
+
+	if (ret)
+		rwsem_acquire(&rwsem->dep_map, 0, 1, _RET_IP_);
+	return ret;
+}
+EXPORT_SYMBOL(rt_down_write_trylock);
+
+void  rt_down_write(struct rw_semaphore *rwsem)
+{
+	rwsem_acquire(&rwsem->dep_map, 0, 0, _RET_IP_);
+	rt_mutex_lock(&rwsem->lock);
+}
+EXPORT_SYMBOL(rt_down_write);
+
+void  rt_down_write_nested(struct rw_semaphore *rwsem, int subclass)
+{
+	rwsem_acquire(&rwsem->dep_map, subclass, 0, _RET_IP_);
+	rt_mutex_lock(&rwsem->lock);
+}
+EXPORT_SYMBOL(rt_down_write_nested);
+
+void rt_down_write_nested_lock(struct rw_semaphore *rwsem,
+			       struct lockdep_map *nest)
+{
+	rwsem_acquire_nest(&rwsem->dep_map, 0, 0, nest, _RET_IP_);
+	rt_mutex_lock(&rwsem->lock);
+}
+EXPORT_SYMBOL(rt_down_write_nested_lock);
+
+int  rt_down_read_trylock(struct rw_semaphore *rwsem)
+{
+	struct rt_mutex *lock = &rwsem->lock;
+	int ret = 1;
+
+	/*
+	 * recursive read locks succeed when current owns the rwsem,
+	 * but not when read_depth == 0 which means that the rwsem is
+	 * write locked.
+	 */
+	if (rt_mutex_owner(lock) != current)
+		ret = rt_mutex_trylock(&rwsem->lock);
+	else if (!rwsem->read_depth)
+		ret = 0;
+
+	if (ret) {
+		rwsem->read_depth++;
+		rwsem_acquire(&rwsem->dep_map, 0, 1, _RET_IP_);
+	}
+	return ret;
+}
+EXPORT_SYMBOL(rt_down_read_trylock);
+
+static void __rt_down_read(struct rw_semaphore *rwsem, int subclass)
+{
+	struct rt_mutex *lock = &rwsem->lock;
+
+	rwsem_acquire_read(&rwsem->dep_map, subclass, 0, _RET_IP_);
+
+	if (rt_mutex_owner(lock) != current)
+		rt_mutex_lock(&rwsem->lock);
+	rwsem->read_depth++;
+}
+
+void  rt_down_read(struct rw_semaphore *rwsem)
+{
+	__rt_down_read(rwsem, 0);
+}
+EXPORT_SYMBOL(rt_down_read);
+
+void  rt_down_read_nested(struct rw_semaphore *rwsem, int subclass)
+{
+	__rt_down_read(rwsem, subclass);
+}
+EXPORT_SYMBOL(rt_down_read_nested);
+
+void  __rt_rwsem_init(struct rw_semaphore *rwsem, const char *name,
+			      struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	/*
+	 * Make sure we are not reinitializing a held lock:
+	 */
+	debug_check_no_locks_freed((void *)rwsem, sizeof(*rwsem));
+	lockdep_init_map(&rwsem->dep_map, name, key, 0);
+#endif
+	rwsem->read_depth = 0;
+	rwsem->lock.save_state = 0;
+}
+EXPORT_SYMBOL(__rt_rwsem_init);
+
+/**
+ * atomic_dec_and_mutex_lock - return holding mutex if we dec to 0
+ * @cnt: the atomic which we are to dec
+ * @lock: the mutex to return holding if we dec to 0
+ *
+ * return true and hold lock if we dec to 0, return false otherwise
+ */
+int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock)
+{
+	/* dec if we can't possibly hit 0 */
+	if (atomic_add_unless(cnt, -1, 1))
+		return 0;
+	/* we might hit 0, so take the lock */
+	mutex_lock(lock);
+	if (!atomic_dec_and_test(cnt)) {
+		/* when we actually did the dec, we didn't hit 0 */
+		mutex_unlock(lock);
+		return 0;
+	}
+	/* we hit 0, and we hold the lock */
+	return 1;
+}
+EXPORT_SYMBOL(atomic_dec_and_mutex_lock);
diff -Nur linux-3.18.12.orig/kernel/locking/rtmutex.c linux-3.18.12/kernel/locking/rtmutex.c
--- linux-3.18.12.orig/kernel/locking/rtmutex.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/locking/rtmutex.c	2015-04-26 13:32:22.439684003 -0500
@@ -7,6 +7,11 @@
  *  Copyright (C) 2005-2006 Timesys Corp., Thomas Gleixner <tglx@timesys.com>
  *  Copyright (C) 2005 Kihon Technologies Inc., Steven Rostedt
  *  Copyright (C) 2006 Esben Nielsen
+ *  Adaptive Spinlocks:
+ *  Copyright (C) 2008 Novell, Inc., Gregory Haskins, Sven Dietrich,
+ *				     and Peter Morreale,
+ * Adaptive Spinlocks simplification:
+ *  Copyright (C) 2008 Red Hat, Inc., Steven Rostedt <srostedt@redhat.com>
  *
  *  See Documentation/locking/rt-mutex-design.txt for details.
  */
@@ -16,6 +21,7 @@
 #include <linux/sched/rt.h>
 #include <linux/sched/deadline.h>
 #include <linux/timer.h>
+#include <linux/ww_mutex.h>
 
 #include "rtmutex_common.h"
 
@@ -69,6 +75,12 @@
 		clear_rt_mutex_waiters(lock);
 }
 
+static int rt_mutex_real_waiter(struct rt_mutex_waiter *waiter)
+{
+	return waiter && waiter != PI_WAKEUP_INPROGRESS &&
+		waiter != PI_REQUEUE_INPROGRESS;
+}
+
 /*
  * We can speed up the acquire/release, if the architecture
  * supports cmpxchg and if there's no debugging state to be set up
@@ -333,6 +345,14 @@
 	return debug_rt_mutex_detect_deadlock(waiter, chwalk);
 }
 
+static void rt_mutex_wake_waiter(struct rt_mutex_waiter *waiter)
+{
+	if (waiter->savestate)
+		wake_up_lock_sleeper(waiter->task);
+	else
+		wake_up_process(waiter->task);
+}
+
 /*
  * Max number of times we'll walk the boosting chain:
  */
@@ -340,7 +360,8 @@
 
 static inline struct rt_mutex *task_blocked_on_lock(struct task_struct *p)
 {
-	return p->pi_blocked_on ? p->pi_blocked_on->lock : NULL;
+	return rt_mutex_real_waiter(p->pi_blocked_on) ?
+		p->pi_blocked_on->lock : NULL;
 }
 
 /*
@@ -477,7 +498,7 @@
 	 * reached or the state of the chain has changed while we
 	 * dropped the locks.
 	 */
-	if (!waiter)
+	if (!rt_mutex_real_waiter(waiter))
 		goto out_unlock_pi;
 
 	/*
@@ -639,13 +660,16 @@
 	 * follow here. This is the end of the chain we are walking.
 	 */
 	if (!rt_mutex_owner(lock)) {
+		struct rt_mutex_waiter *lock_top_waiter;
+
 		/*
 		 * If the requeue [7] above changed the top waiter,
 		 * then we need to wake the new top waiter up to try
 		 * to get the lock.
 		 */
-		if (prerequeue_top_waiter != rt_mutex_top_waiter(lock))
-			wake_up_process(rt_mutex_top_waiter(lock)->task);
+		lock_top_waiter = rt_mutex_top_waiter(lock);
+		if (prerequeue_top_waiter != lock_top_waiter)
+			rt_mutex_wake_waiter(lock_top_waiter);
 		raw_spin_unlock(&lock->wait_lock);
 		return 0;
 	}
@@ -738,6 +762,25 @@
 	return ret;
 }
 
+
+#define STEAL_NORMAL  0
+#define STEAL_LATERAL 1
+
+/*
+ * Note that RT tasks are excluded from lateral-steals to prevent the
+ * introduction of an unbounded latency
+ */
+static inline int lock_is_stealable(struct task_struct *task,
+				    struct task_struct *pendowner, int mode)
+{
+    if (mode == STEAL_NORMAL || rt_task(task)) {
+	    if (task->prio >= pendowner->prio)
+		    return 0;
+    } else if (task->prio > pendowner->prio)
+	    return 0;
+    return 1;
+}
+
 /*
  * Try to take an rt-mutex
  *
@@ -748,8 +791,9 @@
  * @waiter: The waiter that is queued to the lock's wait list if the
  *	    callsite called task_blocked_on_lock(), otherwise NULL
  */
-static int try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
-				struct rt_mutex_waiter *waiter)
+static int __try_to_take_rt_mutex(struct rt_mutex *lock,
+				  struct task_struct *task,
+				  struct rt_mutex_waiter *waiter, int mode)
 {
 	unsigned long flags;
 
@@ -788,8 +832,10 @@
 		 * If waiter is not the highest priority waiter of
 		 * @lock, give up.
 		 */
-		if (waiter != rt_mutex_top_waiter(lock))
+		if (waiter != rt_mutex_top_waiter(lock)) {
+			/* XXX lock_is_stealable() ? */
 			return 0;
+		}
 
 		/*
 		 * We can acquire the lock. Remove the waiter from the
@@ -807,14 +853,10 @@
 		 * not need to be dequeued.
 		 */
 		if (rt_mutex_has_waiters(lock)) {
-			/*
-			 * If @task->prio is greater than or equal to
-			 * the top waiter priority (kernel view),
-			 * @task lost.
-			 */
-			if (task->prio >= rt_mutex_top_waiter(lock)->prio)
-				return 0;
+			struct task_struct *pown = rt_mutex_top_waiter(lock)->task;
 
+			if (task != pown && !lock_is_stealable(task, pown, mode))
+				return 0;
 			/*
 			 * The current top waiter stays enqueued. We
 			 * don't have to change anything in the lock
@@ -863,6 +905,369 @@
 	return 1;
 }
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * preemptible spin_lock functions:
+ */
+static inline void rt_spin_lock_fastlock(struct rt_mutex *lock,
+					 void  (*slowfn)(struct rt_mutex *lock))
+{
+	might_sleep();
+
+	if (likely(rt_mutex_cmpxchg(lock, NULL, current)))
+		rt_mutex_deadlock_account_lock(lock, current);
+	else
+		slowfn(lock);
+}
+
+static inline void rt_spin_lock_fastunlock(struct rt_mutex *lock,
+					   void  (*slowfn)(struct rt_mutex *lock))
+{
+	if (likely(rt_mutex_cmpxchg(lock, current, NULL)))
+		rt_mutex_deadlock_account_unlock(current);
+	else
+		slowfn(lock);
+}
+#ifdef CONFIG_SMP
+/*
+ * Note that owner is a speculative pointer and dereferencing relies
+ * on rcu_read_lock() and the check against the lock owner.
+ */
+static int adaptive_wait(struct rt_mutex *lock,
+			 struct task_struct *owner)
+{
+	int res = 0;
+
+	rcu_read_lock();
+	for (;;) {
+		if (owner != rt_mutex_owner(lock))
+			break;
+		/*
+		 * Ensure that owner->on_cpu is dereferenced _after_
+		 * checking the above to be valid.
+		 */
+		barrier();
+		if (!owner->on_cpu) {
+			res = 1;
+			break;
+		}
+		cpu_relax();
+	}
+	rcu_read_unlock();
+	return res;
+}
+#else
+static int adaptive_wait(struct rt_mutex *lock,
+			 struct task_struct *orig_owner)
+{
+	return 1;
+}
+#endif
+
+# define pi_lock(lock)		raw_spin_lock_irq(lock)
+# define pi_unlock(lock)	raw_spin_unlock_irq(lock)
+
+static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
+				   struct rt_mutex_waiter *waiter,
+				   struct task_struct *task,
+				   enum rtmutex_chainwalk chwalk);
+/*
+ * Slow path lock function spin_lock style: this variant is very
+ * careful not to miss any non-lock wakeups.
+ *
+ * We store the current state under p->pi_lock in p->saved_state and
+ * the try_to_wake_up() code handles this accordingly.
+ */
+static void  noinline __sched rt_spin_lock_slowlock(struct rt_mutex *lock)
+{
+	struct task_struct *lock_owner, *self = current;
+	struct rt_mutex_waiter waiter, *top_waiter;
+	int ret;
+
+	rt_mutex_init_waiter(&waiter, true);
+
+	raw_spin_lock(&lock->wait_lock);
+
+	if (__try_to_take_rt_mutex(lock, self, NULL, STEAL_LATERAL)) {
+		raw_spin_unlock(&lock->wait_lock);
+		return;
+	}
+
+	BUG_ON(rt_mutex_owner(lock) == self);
+
+	/*
+	 * We save whatever state the task is in and we'll restore it
+	 * after acquiring the lock taking real wakeups into account
+	 * as well. We are serialized via pi_lock against wakeups. See
+	 * try_to_wake_up().
+	 */
+	pi_lock(&self->pi_lock);
+	self->saved_state = self->state;
+	__set_current_state(TASK_UNINTERRUPTIBLE);
+	pi_unlock(&self->pi_lock);
+
+	ret = task_blocks_on_rt_mutex(lock, &waiter, self, 0);
+	BUG_ON(ret);
+
+	for (;;) {
+		/* Try to acquire the lock again. */
+		if (__try_to_take_rt_mutex(lock, self, &waiter, STEAL_LATERAL))
+			break;
+
+		top_waiter = rt_mutex_top_waiter(lock);
+		lock_owner = rt_mutex_owner(lock);
+
+		raw_spin_unlock(&lock->wait_lock);
+
+		debug_rt_mutex_print_deadlock(&waiter);
+
+		if (top_waiter != &waiter || adaptive_wait(lock, lock_owner))
+			schedule_rt_mutex(lock);
+
+		raw_spin_lock(&lock->wait_lock);
+
+		pi_lock(&self->pi_lock);
+		__set_current_state(TASK_UNINTERRUPTIBLE);
+		pi_unlock(&self->pi_lock);
+	}
+
+	/*
+	 * Restore the task state to current->saved_state. We set it
+	 * to the original state above and the try_to_wake_up() code
+	 * has possibly updated it when a real (non-rtmutex) wakeup
+	 * happened while we were blocked. Clear saved_state so
+	 * try_to_wakeup() does not get confused.
+	 */
+	pi_lock(&self->pi_lock);
+	__set_current_state(self->saved_state);
+	self->saved_state = TASK_RUNNING;
+	pi_unlock(&self->pi_lock);
+
+	/*
+	 * try_to_take_rt_mutex() sets the waiter bit
+	 * unconditionally. We might have to fix that up:
+	 */
+	fixup_rt_mutex_waiters(lock);
+
+	BUG_ON(rt_mutex_has_waiters(lock) && &waiter == rt_mutex_top_waiter(lock));
+	BUG_ON(!RB_EMPTY_NODE(&waiter.tree_entry));
+
+	raw_spin_unlock(&lock->wait_lock);
+
+	debug_rt_mutex_free_waiter(&waiter);
+}
+
+static void wakeup_next_waiter(struct rt_mutex *lock);
+/*
+ * Slow path to release a rt_mutex spin_lock style
+ */
+static void __sched __rt_spin_lock_slowunlock(struct rt_mutex *lock)
+{
+	debug_rt_mutex_unlock(lock);
+
+	rt_mutex_deadlock_account_unlock(current);
+
+	if (!rt_mutex_has_waiters(lock)) {
+		lock->owner = NULL;
+		raw_spin_unlock(&lock->wait_lock);
+		return;
+	}
+
+	wakeup_next_waiter(lock);
+
+	raw_spin_unlock(&lock->wait_lock);
+
+	/* Undo pi boosting.when necessary */
+	rt_mutex_adjust_prio(current);
+}
+
+static void  noinline __sched rt_spin_lock_slowunlock(struct rt_mutex *lock)
+{
+	raw_spin_lock(&lock->wait_lock);
+	__rt_spin_lock_slowunlock(lock);
+}
+
+static void  noinline __sched rt_spin_lock_slowunlock_hirq(struct rt_mutex *lock)
+{
+	int ret;
+
+	do {
+		ret = raw_spin_trylock(&lock->wait_lock);
+	} while (!ret);
+
+	__rt_spin_lock_slowunlock(lock);
+}
+
+void __lockfunc rt_spin_lock(spinlock_t *lock)
+{
+	rt_spin_lock_fastlock(&lock->lock, rt_spin_lock_slowlock);
+	spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+}
+EXPORT_SYMBOL(rt_spin_lock);
+
+void __lockfunc __rt_spin_lock(struct rt_mutex *lock)
+{
+	rt_spin_lock_fastlock(lock, rt_spin_lock_slowlock);
+}
+EXPORT_SYMBOL(__rt_spin_lock);
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+void __lockfunc rt_spin_lock_nested(spinlock_t *lock, int subclass)
+{
+	rt_spin_lock_fastlock(&lock->lock, rt_spin_lock_slowlock);
+	spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
+}
+EXPORT_SYMBOL(rt_spin_lock_nested);
+#endif
+
+void __lockfunc rt_spin_unlock(spinlock_t *lock)
+{
+	/* NOTE: we always pass in '1' for nested, for simplicity */
+	spin_release(&lock->dep_map, 1, _RET_IP_);
+	rt_spin_lock_fastunlock(&lock->lock, rt_spin_lock_slowunlock);
+}
+EXPORT_SYMBOL(rt_spin_unlock);
+
+void __lockfunc rt_spin_unlock_after_trylock_in_irq(spinlock_t *lock)
+{
+	/* NOTE: we always pass in '1' for nested, for simplicity */
+	spin_release(&lock->dep_map, 1, _RET_IP_);
+	rt_spin_lock_fastunlock(&lock->lock, rt_spin_lock_slowunlock_hirq);
+}
+
+void __lockfunc __rt_spin_unlock(struct rt_mutex *lock)
+{
+	rt_spin_lock_fastunlock(lock, rt_spin_lock_slowunlock);
+}
+EXPORT_SYMBOL(__rt_spin_unlock);
+
+/*
+ * Wait for the lock to get unlocked: instead of polling for an unlock
+ * (like raw spinlocks do), we lock and unlock, to force the kernel to
+ * schedule if there's contention:
+ */
+void __lockfunc rt_spin_unlock_wait(spinlock_t *lock)
+{
+	spin_lock(lock);
+	spin_unlock(lock);
+}
+EXPORT_SYMBOL(rt_spin_unlock_wait);
+
+int __lockfunc __rt_spin_trylock(struct rt_mutex *lock)
+{
+	return rt_mutex_trylock(lock);
+}
+
+int __lockfunc rt_spin_trylock(spinlock_t *lock)
+{
+	int ret = rt_mutex_trylock(&lock->lock);
+
+	if (ret)
+		spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+	return ret;
+}
+EXPORT_SYMBOL(rt_spin_trylock);
+
+int __lockfunc rt_spin_trylock_bh(spinlock_t *lock)
+{
+	int ret;
+
+	local_bh_disable();
+	ret = rt_mutex_trylock(&lock->lock);
+	if (ret) {
+		migrate_disable();
+		spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+	} else
+		local_bh_enable();
+	return ret;
+}
+EXPORT_SYMBOL(rt_spin_trylock_bh);
+
+int __lockfunc rt_spin_trylock_irqsave(spinlock_t *lock, unsigned long *flags)
+{
+	int ret;
+
+	*flags = 0;
+	ret = rt_mutex_trylock(&lock->lock);
+	if (ret) {
+		migrate_disable();
+		spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+	}
+	return ret;
+}
+EXPORT_SYMBOL(rt_spin_trylock_irqsave);
+
+int atomic_dec_and_spin_lock(atomic_t *atomic, spinlock_t *lock)
+{
+	/* Subtract 1 from counter unless that drops it to 0 (ie. it was 1) */
+	if (atomic_add_unless(atomic, -1, 1))
+		return 0;
+	migrate_disable();
+	rt_spin_lock(lock);
+	if (atomic_dec_and_test(atomic))
+		return 1;
+	rt_spin_unlock(lock);
+	migrate_enable();
+	return 0;
+}
+EXPORT_SYMBOL(atomic_dec_and_spin_lock);
+
+	void
+__rt_spin_lock_init(spinlock_t *lock, char *name, struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	/*
+	 * Make sure we are not reinitializing a held lock:
+	 */
+	debug_check_no_locks_freed((void *)lock, sizeof(*lock));
+	lockdep_init_map(&lock->dep_map, name, key, 0);
+#endif
+}
+EXPORT_SYMBOL(__rt_spin_lock_init);
+
+#endif /* PREEMPT_RT_FULL */
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+	static inline int __sched
+__mutex_lock_check_stamp(struct rt_mutex *lock, struct ww_acquire_ctx *ctx)
+{
+	struct ww_mutex *ww = container_of(lock, struct ww_mutex, base.lock);
+	struct ww_acquire_ctx *hold_ctx = ACCESS_ONCE(ww->ctx);
+
+	if (!hold_ctx)
+		return 0;
+
+	if (unlikely(ctx == hold_ctx))
+		return -EALREADY;
+
+	if (ctx->stamp - hold_ctx->stamp <= LONG_MAX &&
+	    (ctx->stamp != hold_ctx->stamp || ctx > hold_ctx)) {
+#ifdef CONFIG_DEBUG_MUTEXES
+		DEBUG_LOCKS_WARN_ON(ctx->contending_lock);
+		ctx->contending_lock = ww;
+#endif
+		return -EDEADLK;
+	}
+
+	return 0;
+}
+#else
+	static inline int __sched
+__mutex_lock_check_stamp(struct rt_mutex *lock, struct ww_acquire_ctx *ctx)
+{
+	BUG();
+	return 0;
+}
+
+#endif
+
+static inline int
+try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
+		     struct rt_mutex_waiter *waiter)
+{
+	return __try_to_take_rt_mutex(lock, task, waiter, STEAL_NORMAL);
+}
+
 /*
  * Task blocks on lock.
  *
@@ -894,6 +1299,23 @@
 		return -EDEADLK;
 
 	raw_spin_lock_irqsave(&task->pi_lock, flags);
+
+	/*
+	 * In the case of futex requeue PI, this will be a proxy
+	 * lock. The task will wake unaware that it is enqueueed on
+	 * this lock. Avoid blocking on two locks and corrupting
+	 * pi_blocked_on via the PI_WAKEUP_INPROGRESS
+	 * flag. futex_wait_requeue_pi() sets this when it wakes up
+	 * before requeue (due to a signal or timeout). Do not enqueue
+	 * the task if PI_WAKEUP_INPROGRESS is set.
+	 */
+	if (task != current && task->pi_blocked_on == PI_WAKEUP_INPROGRESS) {
+		raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+		return -EAGAIN;
+	}
+
+	BUG_ON(rt_mutex_real_waiter(task->pi_blocked_on));
+
 	__rt_mutex_adjust_prio(task);
 	waiter->task = task;
 	waiter->lock = lock;
@@ -917,7 +1339,7 @@
 		rt_mutex_enqueue_pi(owner, waiter);
 
 		__rt_mutex_adjust_prio(owner);
-		if (owner->pi_blocked_on)
+		if (rt_mutex_real_waiter(owner->pi_blocked_on))
 			chain_walk = 1;
 	} else if (rt_mutex_cond_detect_deadlock(waiter, chwalk)) {
 		chain_walk = 1;
@@ -994,7 +1416,7 @@
 	 * long as we hold lock->wait_lock. The waiter task needs to
 	 * acquire it in order to dequeue the waiter.
 	 */
-	wake_up_process(waiter->task);
+	rt_mutex_wake_waiter(waiter);
 }
 
 /*
@@ -1008,7 +1430,7 @@
 {
 	bool is_top_waiter = (waiter == rt_mutex_top_waiter(lock));
 	struct task_struct *owner = rt_mutex_owner(lock);
-	struct rt_mutex *next_lock;
+	struct rt_mutex *next_lock = NULL;
 	unsigned long flags;
 
 	raw_spin_lock_irqsave(&current->pi_lock, flags);
@@ -1033,7 +1455,8 @@
 	__rt_mutex_adjust_prio(owner);
 
 	/* Store the lock on which owner is blocked or NULL */
-	next_lock = task_blocked_on_lock(owner);
+	if (rt_mutex_real_waiter(owner->pi_blocked_on))
+		next_lock = task_blocked_on_lock(owner);
 
 	raw_spin_unlock_irqrestore(&owner->pi_lock, flags);
 
@@ -1069,17 +1492,17 @@
 	raw_spin_lock_irqsave(&task->pi_lock, flags);
 
 	waiter = task->pi_blocked_on;
-	if (!waiter || (waiter->prio == task->prio &&
+	if (!rt_mutex_real_waiter(waiter) || (waiter->prio == task->prio &&
 			!dl_prio(task->prio))) {
 		raw_spin_unlock_irqrestore(&task->pi_lock, flags);
 		return;
 	}
 	next_lock = waiter->lock;
-	raw_spin_unlock_irqrestore(&task->pi_lock, flags);
 
 	/* gets dropped in rt_mutex_adjust_prio_chain()! */
 	get_task_struct(task);
 
+	raw_spin_unlock_irqrestore(&task->pi_lock, flags);
 	rt_mutex_adjust_prio_chain(task, RT_MUTEX_MIN_CHAINWALK, NULL,
 				   next_lock, NULL, task);
 }
@@ -1097,7 +1520,8 @@
 static int __sched
 __rt_mutex_slowlock(struct rt_mutex *lock, int state,
 		    struct hrtimer_sleeper *timeout,
-		    struct rt_mutex_waiter *waiter)
+		    struct rt_mutex_waiter *waiter,
+		    struct ww_acquire_ctx *ww_ctx)
 {
 	int ret = 0;
 
@@ -1120,6 +1544,12 @@
 				break;
 		}
 
+		if (ww_ctx && ww_ctx->acquired > 0) {
+			ret = __mutex_lock_check_stamp(lock, ww_ctx);
+			if (ret)
+				break;
+		}
+
 		raw_spin_unlock(&lock->wait_lock);
 
 		debug_rt_mutex_print_deadlock(waiter);
@@ -1153,25 +1583,102 @@
 	}
 }
 
+static __always_inline void ww_mutex_lock_acquired(struct ww_mutex *ww,
+						   struct ww_acquire_ctx *ww_ctx)
+{
+#ifdef CONFIG_DEBUG_MUTEXES
+	/*
+	 * If this WARN_ON triggers, you used ww_mutex_lock to acquire,
+	 * but released with a normal mutex_unlock in this call.
+	 *
+	 * This should never happen, always use ww_mutex_unlock.
+	 */
+	DEBUG_LOCKS_WARN_ON(ww->ctx);
+
+	/*
+	 * Not quite done after calling ww_acquire_done() ?
+	 */
+	DEBUG_LOCKS_WARN_ON(ww_ctx->done_acquire);
+
+	if (ww_ctx->contending_lock) {
+		/*
+		 * After -EDEADLK you tried to
+		 * acquire a different ww_mutex? Bad!
+		 */
+		DEBUG_LOCKS_WARN_ON(ww_ctx->contending_lock != ww);
+
+		/*
+		 * You called ww_mutex_lock after receiving -EDEADLK,
+		 * but 'forgot' to unlock everything else first?
+		 */
+		DEBUG_LOCKS_WARN_ON(ww_ctx->acquired > 0);
+		ww_ctx->contending_lock = NULL;
+	}
+
+	/*
+	 * Naughty, using a different class will lead to undefined behavior!
+	 */
+	DEBUG_LOCKS_WARN_ON(ww_ctx->ww_class != ww->ww_class);
+#endif
+	ww_ctx->acquired++;
+}
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+static void ww_mutex_account_lock(struct rt_mutex *lock,
+				  struct ww_acquire_ctx *ww_ctx)
+{
+	struct ww_mutex *ww = container_of(lock, struct ww_mutex, base.lock);
+	struct rt_mutex_waiter *waiter, *n;
+
+	/*
+	 * This branch gets optimized out for the common case,
+	 * and is only important for ww_mutex_lock.
+	 */
+	ww_mutex_lock_acquired(ww, ww_ctx);
+	ww->ctx = ww_ctx;
+
+	/*
+	 * Give any possible sleeping processes the chance to wake up,
+	 * so they can recheck if they have to back off.
+	 */
+	rbtree_postorder_for_each_entry_safe(waiter, n, &lock->waiters,
+					     tree_entry) {
+		/* XXX debug rt mutex waiter wakeup */
+
+		BUG_ON(waiter->lock != lock);
+		rt_mutex_wake_waiter(waiter);
+	}
+}
+
+#else
+
+static void ww_mutex_account_lock(struct rt_mutex *lock,
+				  struct ww_acquire_ctx *ww_ctx)
+{
+	BUG();
+}
+#endif
+
 /*
  * Slow path lock function:
  */
 static int __sched
 rt_mutex_slowlock(struct rt_mutex *lock, int state,
 		  struct hrtimer_sleeper *timeout,
-		  enum rtmutex_chainwalk chwalk)
+		  enum rtmutex_chainwalk chwalk,
+		  struct ww_acquire_ctx *ww_ctx)
 {
 	struct rt_mutex_waiter waiter;
 	int ret = 0;
 
-	debug_rt_mutex_init_waiter(&waiter);
-	RB_CLEAR_NODE(&waiter.pi_tree_entry);
-	RB_CLEAR_NODE(&waiter.tree_entry);
+	rt_mutex_init_waiter(&waiter, false);
 
 	raw_spin_lock(&lock->wait_lock);
 
 	/* Try to acquire the lock again: */
 	if (try_to_take_rt_mutex(lock, current, NULL)) {
+		if (ww_ctx)
+			ww_mutex_account_lock(lock, ww_ctx);
 		raw_spin_unlock(&lock->wait_lock);
 		return 0;
 	}
@@ -1188,14 +1695,23 @@
 	ret = task_blocks_on_rt_mutex(lock, &waiter, current, chwalk);
 
 	if (likely(!ret))
-		ret = __rt_mutex_slowlock(lock, state, timeout, &waiter);
+		ret = __rt_mutex_slowlock(lock, state, timeout, &waiter, ww_ctx);
+	else if (ww_ctx) {
+		/* ww_mutex received EDEADLK, let it become EALREADY */
+		ret = __mutex_lock_check_stamp(lock, ww_ctx);
+		BUG_ON(!ret);
+	}
 
 	set_current_state(TASK_RUNNING);
 
 	if (unlikely(ret)) {
 		if (rt_mutex_has_waiters(lock))
 			remove_waiter(lock, &waiter);
-		rt_mutex_handle_deadlock(ret, chwalk, &waiter);
+		/* ww_mutex want to report EDEADLK/EALREADY, let them */
+		if (!ww_ctx)
+			rt_mutex_handle_deadlock(ret, chwalk, &waiter);
+	} else if (ww_ctx) {
+		ww_mutex_account_lock(lock, ww_ctx);
 	}
 
 	/*
@@ -1234,7 +1750,8 @@
 	 * The mutex has currently no owner. Lock the wait lock and
 	 * try to acquire the lock.
 	 */
-	raw_spin_lock(&lock->wait_lock);
+	if (!raw_spin_trylock(&lock->wait_lock))
+		return 0;
 
 	ret = try_to_take_rt_mutex(lock, current, NULL);
 
@@ -1320,31 +1837,36 @@
  */
 static inline int
 rt_mutex_fastlock(struct rt_mutex *lock, int state,
+		  struct ww_acquire_ctx *ww_ctx,
 		  int (*slowfn)(struct rt_mutex *lock, int state,
 				struct hrtimer_sleeper *timeout,
-				enum rtmutex_chainwalk chwalk))
+				enum rtmutex_chainwalk chwalk,
+				struct ww_acquire_ctx *ww_ctx))
 {
 	if (likely(rt_mutex_cmpxchg(lock, NULL, current))) {
 		rt_mutex_deadlock_account_lock(lock, current);
 		return 0;
 	} else
-		return slowfn(lock, state, NULL, RT_MUTEX_MIN_CHAINWALK);
+		return slowfn(lock, state, NULL, RT_MUTEX_MIN_CHAINWALK,
+			      ww_ctx);
 }
 
 static inline int
 rt_mutex_timed_fastlock(struct rt_mutex *lock, int state,
 			struct hrtimer_sleeper *timeout,
 			enum rtmutex_chainwalk chwalk,
+			struct ww_acquire_ctx *ww_ctx,
 			int (*slowfn)(struct rt_mutex *lock, int state,
 				      struct hrtimer_sleeper *timeout,
-				      enum rtmutex_chainwalk chwalk))
+				      enum rtmutex_chainwalk chwalk,
+				      struct ww_acquire_ctx *ww_ctx))
 {
 	if (chwalk == RT_MUTEX_MIN_CHAINWALK &&
 	    likely(rt_mutex_cmpxchg(lock, NULL, current))) {
 		rt_mutex_deadlock_account_lock(lock, current);
 		return 0;
 	} else
-		return slowfn(lock, state, timeout, chwalk);
+		return slowfn(lock, state, timeout, chwalk, ww_ctx);
 }
 
 static inline int
@@ -1377,7 +1899,7 @@
 {
 	might_sleep();
 
-	rt_mutex_fastlock(lock, TASK_UNINTERRUPTIBLE, rt_mutex_slowlock);
+	rt_mutex_fastlock(lock, TASK_UNINTERRUPTIBLE, NULL, rt_mutex_slowlock);
 }
 EXPORT_SYMBOL_GPL(rt_mutex_lock);
 
@@ -1394,7 +1916,7 @@
 {
 	might_sleep();
 
-	return rt_mutex_fastlock(lock, TASK_INTERRUPTIBLE, rt_mutex_slowlock);
+	return rt_mutex_fastlock(lock, TASK_INTERRUPTIBLE, NULL, rt_mutex_slowlock);
 }
 EXPORT_SYMBOL_GPL(rt_mutex_lock_interruptible);
 
@@ -1407,11 +1929,30 @@
 	might_sleep();
 
 	return rt_mutex_timed_fastlock(lock, TASK_INTERRUPTIBLE, timeout,
-				       RT_MUTEX_FULL_CHAINWALK,
+				       RT_MUTEX_FULL_CHAINWALK, NULL,
 				       rt_mutex_slowlock);
 }
 
 /**
+ * rt_mutex_lock_killable - lock a rt_mutex killable
+ *
+ * @lock:              the rt_mutex to be locked
+ * @detect_deadlock:   deadlock detection on/off
+ *
+ * Returns:
+ *  0          on success
+ * -EINTR      when interrupted by a signal
+ * -EDEADLK    when the lock would deadlock (when deadlock detection is on)
+ */
+int __sched rt_mutex_lock_killable(struct rt_mutex *lock)
+{
+	might_sleep();
+
+	return rt_mutex_fastlock(lock, TASK_KILLABLE, NULL, rt_mutex_slowlock);
+}
+EXPORT_SYMBOL_GPL(rt_mutex_lock_killable);
+
+/**
  * rt_mutex_timed_lock - lock a rt_mutex interruptible
  *			the timeout structure is provided
  *			by the caller
@@ -1431,6 +1972,7 @@
 
 	return rt_mutex_timed_fastlock(lock, TASK_INTERRUPTIBLE, timeout,
 				       RT_MUTEX_MIN_CHAINWALK,
+				       NULL,
 				       rt_mutex_slowlock);
 }
 EXPORT_SYMBOL_GPL(rt_mutex_timed_lock);
@@ -1489,13 +2031,12 @@
 void __rt_mutex_init(struct rt_mutex *lock, const char *name)
 {
 	lock->owner = NULL;
-	raw_spin_lock_init(&lock->wait_lock);
 	lock->waiters = RB_ROOT;
 	lock->waiters_leftmost = NULL;
 
 	debug_rt_mutex_init(lock, name);
 }
-EXPORT_SYMBOL_GPL(__rt_mutex_init);
+EXPORT_SYMBOL(__rt_mutex_init);
 
 /**
  * rt_mutex_init_proxy_locked - initialize and lock a rt_mutex on behalf of a
@@ -1510,7 +2051,7 @@
 void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
 				struct task_struct *proxy_owner)
 {
-	__rt_mutex_init(lock, NULL);
+	rt_mutex_init(lock);
 	debug_rt_mutex_proxy_lock(lock, proxy_owner);
 	rt_mutex_set_owner(lock, proxy_owner);
 	rt_mutex_deadlock_account_lock(lock, proxy_owner);
@@ -1558,6 +2099,35 @@
 		return 1;
 	}
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+	/*
+	 * In PREEMPT_RT there's an added race.
+	 * If the task, that we are about to requeue, times out,
+	 * it can set the PI_WAKEUP_INPROGRESS. This tells the requeue
+	 * to skip this task. But right after the task sets
+	 * its pi_blocked_on to PI_WAKEUP_INPROGRESS it can then
+	 * block on the spin_lock(&hb->lock), which in RT is an rtmutex.
+	 * This will replace the PI_WAKEUP_INPROGRESS with the actual
+	 * lock that it blocks on. We *must not* place this task
+	 * on this proxy lock in that case.
+	 *
+	 * To prevent this race, we first take the task's pi_lock
+	 * and check if it has updated its pi_blocked_on. If it has,
+	 * we assume that it woke up and we return -EAGAIN.
+	 * Otherwise, we set the task's pi_blocked_on to
+	 * PI_REQUEUE_INPROGRESS, so that if the task is waking up
+	 * it will know that we are in the process of requeuing it.
+	 */
+	raw_spin_lock_irq(&task->pi_lock);
+	if (task->pi_blocked_on) {
+		raw_spin_unlock_irq(&task->pi_lock);
+		raw_spin_unlock(&lock->wait_lock);
+		return -EAGAIN;
+	}
+	task->pi_blocked_on = PI_REQUEUE_INPROGRESS;
+	raw_spin_unlock_irq(&task->pi_lock);
+#endif
+
 	/* We enforce deadlock detection for futexes */
 	ret = task_blocks_on_rt_mutex(lock, waiter, task,
 				      RT_MUTEX_FULL_CHAINWALK);
@@ -1627,7 +2197,7 @@
 
 	set_current_state(TASK_INTERRUPTIBLE);
 
-	ret = __rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, to, waiter);
+	ret = __rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, to, waiter, NULL);
 
 	set_current_state(TASK_RUNNING);
 
@@ -1644,3 +2214,89 @@
 
 	return ret;
 }
+
+static inline int
+ww_mutex_deadlock_injection(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
+{
+#ifdef CONFIG_DEBUG_WW_MUTEX_SLOWPATH
+	unsigned tmp;
+
+	if (ctx->deadlock_inject_countdown-- == 0) {
+		tmp = ctx->deadlock_inject_interval;
+		if (tmp > UINT_MAX/4)
+			tmp = UINT_MAX;
+		else
+			tmp = tmp*2 + tmp + tmp/2;
+
+		ctx->deadlock_inject_interval = tmp;
+		ctx->deadlock_inject_countdown = tmp;
+		ctx->contending_lock = lock;
+
+		ww_mutex_unlock(lock);
+
+		return -EDEADLK;
+	}
+#endif
+
+	return 0;
+}
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+int __sched
+__ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ww_ctx)
+{
+	int ret;
+
+	might_sleep();
+
+	mutex_acquire_nest(&lock->base.dep_map, 0, 0, &ww_ctx->dep_map, _RET_IP_);
+	ret = rt_mutex_slowlock(&lock->base.lock, TASK_INTERRUPTIBLE, NULL, 0, ww_ctx);
+	if (ret)
+		mutex_release(&lock->base.dep_map, 1, _RET_IP_);
+	else if (!ret && ww_ctx->acquired > 1)
+		return ww_mutex_deadlock_injection(lock, ww_ctx);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(__ww_mutex_lock_interruptible);
+
+int __sched
+__ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ww_ctx)
+{
+	int ret;
+
+	might_sleep();
+
+	mutex_acquire_nest(&lock->base.dep_map, 0, 0, &ww_ctx->dep_map, _RET_IP_);
+	ret = rt_mutex_slowlock(&lock->base.lock, TASK_UNINTERRUPTIBLE, NULL, 0, ww_ctx);
+	if (ret)
+		mutex_release(&lock->base.dep_map, 1, _RET_IP_);
+	else if (!ret && ww_ctx->acquired > 1)
+		return ww_mutex_deadlock_injection(lock, ww_ctx);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(__ww_mutex_lock);
+
+void __sched ww_mutex_unlock(struct ww_mutex *lock)
+{
+	int nest = !!lock->ctx;
+
+	/*
+	 * The unlocking fastpath is the 0->1 transition from 'locked'
+	 * into 'unlocked' state:
+	 */
+	if (nest) {
+#ifdef CONFIG_DEBUG_MUTEXES
+		DEBUG_LOCKS_WARN_ON(!lock->ctx->acquired);
+#endif
+		if (lock->ctx->acquired > 0)
+			lock->ctx->acquired--;
+		lock->ctx = NULL;
+	}
+
+	mutex_release(&lock->base.dep_map, nest, _RET_IP_);
+	rt_mutex_unlock(&lock->base.lock);
+}
+EXPORT_SYMBOL(ww_mutex_unlock);
+#endif
diff -Nur linux-3.18.12.orig/kernel/locking/rtmutex_common.h linux-3.18.12/kernel/locking/rtmutex_common.h
--- linux-3.18.12.orig/kernel/locking/rtmutex_common.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/locking/rtmutex_common.h	2015-04-26 13:32:22.439684003 -0500
@@ -49,6 +49,7 @@
 	struct rb_node          pi_tree_entry;
 	struct task_struct	*task;
 	struct rt_mutex		*lock;
+	bool			savestate;
 #ifdef CONFIG_DEBUG_RT_MUTEXES
 	unsigned long		ip;
 	struct pid		*deadlock_task_pid;
@@ -119,6 +120,9 @@
 /*
  * PI-futex support (proxy locking functions, etc.):
  */
+#define PI_WAKEUP_INPROGRESS	((struct rt_mutex_waiter *) 1)
+#define PI_REQUEUE_INPROGRESS	((struct rt_mutex_waiter *) 2)
+
 extern struct task_struct *rt_mutex_next_owner(struct rt_mutex *lock);
 extern void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
 				       struct task_struct *proxy_owner);
@@ -138,4 +142,14 @@
 # include "rtmutex.h"
 #endif
 
+static inline void
+rt_mutex_init_waiter(struct rt_mutex_waiter *waiter, bool savestate)
+{
+	debug_rt_mutex_init_waiter(waiter);
+	waiter->task = NULL;
+	waiter->savestate = savestate;
+	RB_CLEAR_NODE(&waiter->pi_tree_entry);
+	RB_CLEAR_NODE(&waiter->tree_entry);
+}
+
 #endif
diff -Nur linux-3.18.12.orig/kernel/locking/spinlock.c linux-3.18.12/kernel/locking/spinlock.c
--- linux-3.18.12.orig/kernel/locking/spinlock.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/locking/spinlock.c	2015-04-26 13:32:22.439684003 -0500
@@ -124,8 +124,11 @@
  *         __[spin|read|write]_lock_bh()
  */
 BUILD_LOCK_OPS(spin, raw_spinlock);
+
+#ifndef CONFIG_PREEMPT_RT_FULL
 BUILD_LOCK_OPS(read, rwlock);
 BUILD_LOCK_OPS(write, rwlock);
+#endif
 
 #endif
 
@@ -209,6 +212,8 @@
 EXPORT_SYMBOL(_raw_spin_unlock_bh);
 #endif
 
+#ifndef CONFIG_PREEMPT_RT_FULL
+
 #ifndef CONFIG_INLINE_READ_TRYLOCK
 int __lockfunc _raw_read_trylock(rwlock_t *lock)
 {
@@ -353,6 +358,8 @@
 EXPORT_SYMBOL(_raw_write_unlock_bh);
 #endif
 
+#endif /* !PREEMPT_RT_FULL */
+
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 
 void __lockfunc _raw_spin_lock_nested(raw_spinlock_t *lock, int subclass)
diff -Nur linux-3.18.12.orig/kernel/locking/spinlock_debug.c linux-3.18.12/kernel/locking/spinlock_debug.c
--- linux-3.18.12.orig/kernel/locking/spinlock_debug.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/locking/spinlock_debug.c	2015-04-26 13:32:22.439684003 -0500
@@ -31,6 +31,7 @@
 
 EXPORT_SYMBOL(__raw_spin_lock_init);
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 void __rwlock_init(rwlock_t *lock, const char *name,
 		   struct lock_class_key *key)
 {
@@ -48,6 +49,7 @@
 }
 
 EXPORT_SYMBOL(__rwlock_init);
+#endif
 
 static void spin_dump(raw_spinlock_t *lock, const char *msg)
 {
@@ -159,6 +161,7 @@
 	arch_spin_unlock(&lock->raw_lock);
 }
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 static void rwlock_bug(rwlock_t *lock, const char *msg)
 {
 	if (!debug_locks_off())
@@ -300,3 +303,5 @@
 	debug_write_unlock(lock);
 	arch_write_unlock(&lock->raw_lock);
 }
+
+#endif
diff -Nur linux-3.18.12.orig/kernel/panic.c linux-3.18.12/kernel/panic.c
--- linux-3.18.12.orig/kernel/panic.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/panic.c	2015-04-26 13:32:22.439684003 -0500
@@ -384,9 +384,11 @@
 
 static int init_oops_id(void)
 {
+#ifndef CONFIG_PREEMPT_RT_FULL
 	if (!oops_id)
 		get_random_bytes(&oops_id, sizeof(oops_id));
 	else
+#endif
 		oops_id++;
 
 	return 0;
diff -Nur linux-3.18.12.orig/kernel/power/hibernate.c linux-3.18.12/kernel/power/hibernate.c
--- linux-3.18.12.orig/kernel/power/hibernate.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/power/hibernate.c	2015-04-26 13:32:22.439684003 -0500
@@ -287,6 +287,8 @@
 
 	local_irq_disable();
 
+	system_state = SYSTEM_SUSPEND;
+
 	error = syscore_suspend();
 	if (error) {
 		printk(KERN_ERR "PM: Some system devices failed to power down, "
@@ -316,6 +318,7 @@
 	syscore_resume();
 
  Enable_irqs:
+	system_state = SYSTEM_RUNNING;
 	local_irq_enable();
 
  Enable_cpus:
@@ -439,6 +442,7 @@
 		goto Enable_cpus;
 
 	local_irq_disable();
+	system_state = SYSTEM_SUSPEND;
 
 	error = syscore_suspend();
 	if (error)
@@ -472,6 +476,7 @@
 	syscore_resume();
 
  Enable_irqs:
+	system_state = SYSTEM_RUNNING;
 	local_irq_enable();
 
  Enable_cpus:
@@ -557,6 +562,7 @@
 		goto Platform_finish;
 
 	local_irq_disable();
+	system_state = SYSTEM_SUSPEND;
 	syscore_suspend();
 	if (pm_wakeup_pending()) {
 		error = -EAGAIN;
@@ -569,6 +575,7 @@
 
  Power_up:
 	syscore_resume();
+	system_state = SYSTEM_RUNNING;
 	local_irq_enable();
 	enable_nonboot_cpus();
 
diff -Nur linux-3.18.12.orig/kernel/power/suspend.c linux-3.18.12/kernel/power/suspend.c
--- linux-3.18.12.orig/kernel/power/suspend.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/power/suspend.c	2015-04-26 13:32:22.439684003 -0500
@@ -318,6 +318,8 @@
 	arch_suspend_disable_irqs();
 	BUG_ON(!irqs_disabled());
 
+	system_state = SYSTEM_SUSPEND;
+
 	error = syscore_suspend();
 	if (!error) {
 		*wakeup = pm_wakeup_pending();
@@ -332,6 +334,8 @@
 		syscore_resume();
 	}
 
+	system_state = SYSTEM_RUNNING;
+
 	arch_suspend_enable_irqs();
 	BUG_ON(irqs_disabled());
 
diff -Nur linux-3.18.12.orig/kernel/printk/printk.c linux-3.18.12/kernel/printk/printk.c
--- linux-3.18.12.orig/kernel/printk/printk.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/printk/printk.c	2015-04-26 13:32:22.439684003 -0500
@@ -1165,6 +1165,7 @@
 {
 	char *text;
 	int len = 0;
+	int attempts = 0;
 
 	text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
 	if (!text)
@@ -1176,7 +1177,14 @@
 		u64 seq;
 		u32 idx;
 		enum log_flags prev;
-
+		int num_msg;
+try_again:
+		attempts++;
+		if (attempts > 10) {
+			len = -EBUSY;
+			goto out;
+		}
+		num_msg = 0;
 		if (clear_seq < log_first_seq) {
 			/* messages are gone, move to first available one */
 			clear_seq = log_first_seq;
@@ -1197,6 +1205,14 @@
 			prev = msg->flags;
 			idx = log_next(idx);
 			seq++;
+			num_msg++;
+			if (num_msg > 5) {
+				num_msg = 0;
+				raw_spin_unlock_irq(&logbuf_lock);
+				raw_spin_lock_irq(&logbuf_lock);
+				if (clear_seq < log_first_seq)
+					goto try_again;
+			}
 		}
 
 		/* move first record forward until length fits into the buffer */
@@ -1210,6 +1226,14 @@
 			prev = msg->flags;
 			idx = log_next(idx);
 			seq++;
+			num_msg++;
+			if (num_msg > 5) {
+				num_msg = 0;
+				raw_spin_unlock_irq(&logbuf_lock);
+				raw_spin_lock_irq(&logbuf_lock);
+				if (clear_seq < log_first_seq)
+					goto try_again;
+			}
 		}
 
 		/* last message fitting into this dump */
@@ -1250,6 +1274,7 @@
 		clear_seq = log_next_seq;
 		clear_idx = log_next_idx;
 	}
+out:
 	raw_spin_unlock_irq(&logbuf_lock);
 
 	kfree(text);
@@ -1407,6 +1432,7 @@
 	if (!console_drivers)
 		return;
 
+	migrate_disable();
 	for_each_console(con) {
 		if (exclusive_console && con != exclusive_console)
 			continue;
@@ -1419,6 +1445,7 @@
 			continue;
 		con->write(con, text, len);
 	}
+	migrate_enable();
 }
 
 /*
@@ -1479,6 +1506,15 @@
 static int console_trylock_for_printk(void)
 {
 	unsigned int cpu = smp_processor_id();
+#ifdef CONFIG_PREEMPT_RT_FULL
+	int lock = !early_boot_irqs_disabled && (preempt_count() == 0) &&
+		!irqs_disabled();
+#else
+	int lock = 1;
+#endif
+
+	if (!lock)
+		return 0;
 
 	if (!console_trylock())
 		return 0;
@@ -1613,6 +1649,62 @@
 	return textlen;
 }
 
+#ifdef CONFIG_EARLY_PRINTK
+struct console *early_console;
+
+void early_vprintk(const char *fmt, va_list ap)
+{
+	if (early_console) {
+		char buf[512];
+		int n = vscnprintf(buf, sizeof(buf), fmt, ap);
+
+		early_console->write(early_console, buf, n);
+	}
+}
+
+asmlinkage void early_printk(const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	early_vprintk(fmt, ap);
+	va_end(ap);
+}
+
+/*
+ * This is independent of any log levels - a global
+ * kill switch that turns off all of printk.
+ *
+ * Used by the NMI watchdog if early-printk is enabled.
+ */
+static bool __read_mostly printk_killswitch;
+
+static int __init force_early_printk_setup(char *str)
+{
+	printk_killswitch = true;
+	return 0;
+}
+early_param("force_early_printk", force_early_printk_setup);
+
+void printk_kill(void)
+{
+	printk_killswitch = true;
+}
+
+static int forced_early_printk(const char *fmt, va_list ap)
+{
+	if (!printk_killswitch)
+		return 0;
+	early_vprintk(fmt, ap);
+	return 1;
+}
+#else
+static inline int forced_early_printk(const char *fmt, va_list ap)
+{
+	return 0;
+}
+#endif
+
 asmlinkage int vprintk_emit(int facility, int level,
 			    const char *dict, size_t dictlen,
 			    const char *fmt, va_list args)
@@ -1629,6 +1721,13 @@
 	/* cpu currently holding logbuf_lock in this function */
 	static volatile unsigned int logbuf_cpu = UINT_MAX;
 
+	/*
+	 * Fall back to early_printk if a debugging subsystem has
+	 * killed printk output
+	 */
+	if (unlikely(forced_early_printk(fmt, args)))
+		return 1;
+
 	if (level == SCHED_MESSAGE_LOGLEVEL) {
 		level = -1;
 		in_sched = true;
@@ -1769,8 +1868,7 @@
 		 * console_sem which would prevent anyone from printing to
 		 * console
 		 */
-		preempt_disable();
-
+		migrate_disable();
 		/*
 		 * Try to acquire and then immediately release the console
 		 * semaphore.  The release will print out buffers and wake up
@@ -1778,7 +1876,7 @@
 		 */
 		if (console_trylock_for_printk())
 			console_unlock();
-		preempt_enable();
+		migrate_enable();
 		lockdep_on();
 	}
 
@@ -1878,29 +1976,6 @@
 
 #endif /* CONFIG_PRINTK */
 
-#ifdef CONFIG_EARLY_PRINTK
-struct console *early_console;
-
-void early_vprintk(const char *fmt, va_list ap)
-{
-	if (early_console) {
-		char buf[512];
-		int n = vscnprintf(buf, sizeof(buf), fmt, ap);
-
-		early_console->write(early_console, buf, n);
-	}
-}
-
-asmlinkage __visible void early_printk(const char *fmt, ...)
-{
-	va_list ap;
-
-	va_start(ap, fmt);
-	early_vprintk(fmt, ap);
-	va_end(ap);
-}
-#endif
-
 static int __add_preferred_console(char *name, int idx, char *options,
 				   char *brl_options)
 {
@@ -2140,11 +2215,16 @@
 		goto out;
 
 	len = cont_print_text(text, size);
+#ifndef CONFIG_PREEMPT_RT_FULL
 	raw_spin_unlock(&logbuf_lock);
 	stop_critical_timings();
 	call_console_drivers(cont.level, text, len);
 	start_critical_timings();
 	local_irq_restore(flags);
+#else
+	raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+	call_console_drivers(cont.level, text, len);
+#endif
 	return;
 out:
 	raw_spin_unlock_irqrestore(&logbuf_lock, flags);
@@ -2232,12 +2312,17 @@
 		console_idx = log_next(console_idx);
 		console_seq++;
 		console_prev = msg->flags;
+#ifdef CONFIG_PREEMPT_RT_FULL
+		raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+		call_console_drivers(level, text, len);
+#else
 		raw_spin_unlock(&logbuf_lock);
 
 		stop_critical_timings();	/* don't trace print latency */
 		call_console_drivers(level, text, len);
 		start_critical_timings();
 		local_irq_restore(flags);
+#endif
 	}
 	console_locked = 0;
 
diff -Nur linux-3.18.12.orig/kernel/ptrace.c linux-3.18.12/kernel/ptrace.c
--- linux-3.18.12.orig/kernel/ptrace.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/ptrace.c	2015-04-26 13:32:22.439684003 -0500
@@ -129,7 +129,12 @@
 
 	spin_lock_irq(&task->sighand->siglock);
 	if (task_is_traced(task) && !__fatal_signal_pending(task)) {
-		task->state = __TASK_TRACED;
+		raw_spin_lock_irq(&task->pi_lock);
+		if (task->state & __TASK_TRACED)
+			task->state = __TASK_TRACED;
+		else
+			task->saved_state = __TASK_TRACED;
+		raw_spin_unlock_irq(&task->pi_lock);
 		ret = true;
 	}
 	spin_unlock_irq(&task->sighand->siglock);
diff -Nur linux-3.18.12.orig/kernel/rcu/tiny.c linux-3.18.12/kernel/rcu/tiny.c
--- linux-3.18.12.orig/kernel/rcu/tiny.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/rcu/tiny.c	2015-04-26 13:32:22.439684003 -0500
@@ -370,6 +370,7 @@
 }
 EXPORT_SYMBOL_GPL(call_rcu_sched);
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 /*
  * Post an RCU bottom-half callback to be invoked after any subsequent
  * quiescent state.
@@ -379,6 +380,7 @@
 	__call_rcu(head, func, &rcu_bh_ctrlblk);
 }
 EXPORT_SYMBOL_GPL(call_rcu_bh);
+#endif
 
 void rcu_init(void)
 {
diff -Nur linux-3.18.12.orig/kernel/rcu/tree.c linux-3.18.12/kernel/rcu/tree.c
--- linux-3.18.12.orig/kernel/rcu/tree.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/rcu/tree.c	2015-04-26 13:32:22.439684003 -0500
@@ -56,6 +56,11 @@
 #include <linux/random.h>
 #include <linux/ftrace_event.h>
 #include <linux/suspend.h>
+#include <linux/delay.h>
+#include <linux/gfp.h>
+#include <linux/oom.h>
+#include <linux/smpboot.h>
+#include "../time/tick-internal.h"
 
 #include "tree.h"
 #include "rcu.h"
@@ -152,8 +157,6 @@
  */
 static int rcu_scheduler_fully_active __read_mostly;
 
-#ifdef CONFIG_RCU_BOOST
-
 /*
  * Control variables for per-CPU and per-rcu_node kthreads.  These
  * handle all flavors of RCU.
@@ -163,8 +166,6 @@
 DEFINE_PER_CPU(unsigned int, rcu_cpu_kthread_loops);
 DEFINE_PER_CPU(char, rcu_cpu_has_work);
 
-#endif /* #ifdef CONFIG_RCU_BOOST */
-
 static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu);
 static void invoke_rcu_core(void);
 static void invoke_rcu_callbacks(struct rcu_state *rsp, struct rcu_data *rdp);
@@ -207,6 +208,19 @@
 	}
 }
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+static void rcu_preempt_qs(void);
+
+void rcu_bh_qs(void)
+{
+	unsigned long flags;
+
+	/* Callers to this function, rcu_preempt_qs(), must disable irqs. */
+	local_irq_save(flags);
+	rcu_preempt_qs();
+	local_irq_restore(flags);
+}
+#else
 void rcu_bh_qs(void)
 {
 	if (!__this_cpu_read(rcu_bh_data.passed_quiesce)) {
@@ -216,6 +230,7 @@
 		__this_cpu_write(rcu_bh_data.passed_quiesce, 1);
 	}
 }
+#endif
 
 static DEFINE_PER_CPU(int, rcu_sched_qs_mask);
 
@@ -336,6 +351,7 @@
 }
 EXPORT_SYMBOL_GPL(rcu_batches_completed_sched);
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 /*
  * Return the number of RCU BH batches processed thus far for debug & stats.
  */
@@ -363,6 +379,13 @@
 }
 EXPORT_SYMBOL_GPL(rcu_bh_force_quiescent_state);
 
+#else
+void rcu_force_quiescent_state(void)
+{
+}
+EXPORT_SYMBOL_GPL(rcu_force_quiescent_state);
+#endif
+
 /*
  * Show the state of the grace-period kthreads.
  */
@@ -1411,7 +1434,7 @@
 	    !ACCESS_ONCE(rsp->gp_flags) ||
 	    !rsp->gp_kthread)
 		return;
-	wake_up(&rsp->gp_wq);
+	swait_wake(&rsp->gp_wq);
 }
 
 /*
@@ -1793,7 +1816,7 @@
 					       ACCESS_ONCE(rsp->gpnum),
 					       TPS("reqwait"));
 			rsp->gp_state = RCU_GP_WAIT_GPS;
-			wait_event_interruptible(rsp->gp_wq,
+			swait_event_interruptible(rsp->gp_wq,
 						 ACCESS_ONCE(rsp->gp_flags) &
 						 RCU_GP_FLAG_INIT);
 			/* Locking provides needed memory barrier. */
@@ -1821,7 +1844,7 @@
 					       ACCESS_ONCE(rsp->gpnum),
 					       TPS("fqswait"));
 			rsp->gp_state = RCU_GP_WAIT_FQS;
-			ret = wait_event_interruptible_timeout(rsp->gp_wq,
+			ret = swait_event_interruptible_timeout(rsp->gp_wq,
 					((gf = ACCESS_ONCE(rsp->gp_flags)) &
 					 RCU_GP_FLAG_FQS) ||
 					(!ACCESS_ONCE(rnp->qsmask) &&
@@ -2565,16 +2588,14 @@
 /*
  * Do RCU core processing for the current CPU.
  */
-static void rcu_process_callbacks(struct softirq_action *unused)
+static void rcu_process_callbacks(void)
 {
 	struct rcu_state *rsp;
 
 	if (cpu_is_offline(smp_processor_id()))
 		return;
-	trace_rcu_utilization(TPS("Start RCU core"));
 	for_each_rcu_flavor(rsp)
 		__rcu_process_callbacks(rsp);
-	trace_rcu_utilization(TPS("End RCU core"));
 }
 
 /*
@@ -2588,18 +2609,105 @@
 {
 	if (unlikely(!ACCESS_ONCE(rcu_scheduler_fully_active)))
 		return;
-	if (likely(!rsp->boost)) {
-		rcu_do_batch(rsp, rdp);
+	rcu_do_batch(rsp, rdp);
+}
+
+static void rcu_wake_cond(struct task_struct *t, int status)
+{
+	/*
+	 * If the thread is yielding, only wake it when this
+	 * is invoked from idle
+	 */
+	if (t && (status != RCU_KTHREAD_YIELDING || is_idle_task(current)))
+		wake_up_process(t);
+}
+
+/*
+ * Wake up this CPU's rcuc kthread to do RCU core processing.
+ */
+static void invoke_rcu_core(void)
+{
+	unsigned long flags;
+	struct task_struct *t;
+
+	if (!cpu_online(smp_processor_id()))
 		return;
+	local_irq_save(flags);
+	__this_cpu_write(rcu_cpu_has_work, 1);
+	t = __this_cpu_read(rcu_cpu_kthread_task);
+	if (t != NULL && current != t)
+		rcu_wake_cond(t, __this_cpu_read(rcu_cpu_kthread_status));
+	local_irq_restore(flags);
+}
+
+static void rcu_cpu_kthread_park(unsigned int cpu)
+{
+	per_cpu(rcu_cpu_kthread_status, cpu) = RCU_KTHREAD_OFFCPU;
+}
+
+static int rcu_cpu_kthread_should_run(unsigned int cpu)
+{
+	return __this_cpu_read(rcu_cpu_has_work);
+}
+
+/*
+ * Per-CPU kernel thread that invokes RCU callbacks.  This replaces the
+ * RCU softirq used in flavors and configurations of RCU that do not
+ * support RCU priority boosting.
+ */
+static void rcu_cpu_kthread(unsigned int cpu)
+{
+	unsigned int *statusp = &__get_cpu_var(rcu_cpu_kthread_status);
+	char work, *workp = &__get_cpu_var(rcu_cpu_has_work);
+	int spincnt;
+
+	for (spincnt = 0; spincnt < 10; spincnt++) {
+		trace_rcu_utilization(TPS("Start CPU kthread@rcu_wait"));
+		local_bh_disable();
+		*statusp = RCU_KTHREAD_RUNNING;
+		this_cpu_inc(rcu_cpu_kthread_loops);
+		local_irq_disable();
+		work = *workp;
+		*workp = 0;
+		local_irq_enable();
+		if (work)
+			rcu_process_callbacks();
+		local_bh_enable();
+		if (*workp == 0) {
+			trace_rcu_utilization(TPS("End CPU kthread@rcu_wait"));
+			*statusp = RCU_KTHREAD_WAITING;
+			return;
+		}
 	}
-	invoke_rcu_callbacks_kthread();
+	*statusp = RCU_KTHREAD_YIELDING;
+	trace_rcu_utilization(TPS("Start CPU kthread@rcu_yield"));
+	schedule_timeout_interruptible(2);
+	trace_rcu_utilization(TPS("End CPU kthread@rcu_yield"));
+	*statusp = RCU_KTHREAD_WAITING;
 }
 
-static void invoke_rcu_core(void)
+static struct smp_hotplug_thread rcu_cpu_thread_spec = {
+	.store			= &rcu_cpu_kthread_task,
+	.thread_should_run	= rcu_cpu_kthread_should_run,
+	.thread_fn		= rcu_cpu_kthread,
+	.thread_comm		= "rcuc/%u",
+	.setup			= rcu_cpu_kthread_setup,
+	.park			= rcu_cpu_kthread_park,
+};
+
+/*
+ * Spawn per-CPU RCU core processing kthreads.
+ */
+static int __init rcu_spawn_core_kthreads(void)
 {
-	if (cpu_online(smp_processor_id()))
-		raise_softirq(RCU_SOFTIRQ);
+	int cpu;
+
+	for_each_possible_cpu(cpu)
+		per_cpu(rcu_cpu_has_work, cpu) = 0;
+	BUG_ON(smpboot_register_percpu_thread(&rcu_cpu_thread_spec));
+	return 0;
 }
+early_initcall(rcu_spawn_core_kthreads);
 
 /*
  * Handle any core-RCU processing required by a call_rcu() invocation.
@@ -2734,6 +2842,7 @@
 }
 EXPORT_SYMBOL_GPL(call_rcu_sched);
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 /*
  * Queue an RCU callback for invocation after a quicker grace period.
  */
@@ -2742,6 +2851,7 @@
 	__call_rcu(head, func, &rcu_bh_state, -1, 0);
 }
 EXPORT_SYMBOL_GPL(call_rcu_bh);
+#endif
 
 /*
  * Queue an RCU callback for lazy invocation after a grace period.
@@ -2833,6 +2943,7 @@
 }
 EXPORT_SYMBOL_GPL(synchronize_sched);
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 /**
  * synchronize_rcu_bh - wait until an rcu_bh grace period has elapsed.
  *
@@ -2859,6 +2970,7 @@
 		wait_rcu_gp(call_rcu_bh);
 }
 EXPORT_SYMBOL_GPL(synchronize_rcu_bh);
+#endif
 
 /**
  * get_state_synchronize_rcu - Snapshot current RCU state
@@ -3341,6 +3453,7 @@
 	mutex_unlock(&rsp->barrier_mutex);
 }
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 /**
  * rcu_barrier_bh - Wait until all in-flight call_rcu_bh() callbacks complete.
  */
@@ -3349,6 +3462,7 @@
 	_rcu_barrier(&rcu_bh_state);
 }
 EXPORT_SYMBOL_GPL(rcu_barrier_bh);
+#endif
 
 /**
  * rcu_barrier_sched - Wait for in-flight call_rcu_sched() callbacks.
@@ -3658,7 +3772,7 @@
 	}
 
 	rsp->rda = rda;
-	init_waitqueue_head(&rsp->gp_wq);
+	init_swait_head(&rsp->gp_wq);
 	rnp = rsp->level[rcu_num_lvls - 1];
 	for_each_possible_cpu(i) {
 		while (i > rnp->grphi)
@@ -3755,7 +3869,6 @@
 	rcu_init_one(&rcu_bh_state, &rcu_bh_data);
 	rcu_init_one(&rcu_sched_state, &rcu_sched_data);
 	__rcu_init_preempt();
-	open_softirq(RCU_SOFTIRQ, rcu_process_callbacks);
 
 	/*
 	 * We don't need protection against CPU-hotplug here because
diff -Nur linux-3.18.12.orig/kernel/rcu/tree.h linux-3.18.12/kernel/rcu/tree.h
--- linux-3.18.12.orig/kernel/rcu/tree.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/rcu/tree.h	2015-04-26 13:32:22.443684003 -0500
@@ -28,6 +28,7 @@
 #include <linux/cpumask.h>
 #include <linux/seqlock.h>
 #include <linux/irq_work.h>
+#include <linux/wait-simple.h>
 
 /*
  * Define shape of hierarchy based on NR_CPUS, CONFIG_RCU_FANOUT, and
@@ -172,11 +173,6 @@
 				/*  queued on this rcu_node structure that */
 				/*  are blocking the current grace period, */
 				/*  there can be no such task. */
-	struct completion boost_completion;
-				/* Used to ensure that the rt_mutex used */
-				/*  to carry out the boosting is fully */
-				/*  released with no future boostee accesses */
-				/*  before that rt_mutex is re-initialized. */
 	struct rt_mutex boost_mtx;
 				/* Used only for the priority-boosting */
 				/*  side effect, not as a lock. */
@@ -208,7 +204,7 @@
 				/*  This can happen due to race conditions. */
 #endif /* #ifdef CONFIG_RCU_BOOST */
 #ifdef CONFIG_RCU_NOCB_CPU
-	wait_queue_head_t nocb_gp_wq[2];
+	struct swait_head nocb_gp_wq[2];
 				/* Place for rcu_nocb_kthread() to wait GP. */
 #endif /* #ifdef CONFIG_RCU_NOCB_CPU */
 	int need_future_gp[2];
@@ -348,7 +344,7 @@
 	atomic_long_t nocb_follower_count_lazy; /*  (approximate). */
 	int nocb_p_count;		/* # CBs being invoked by kthread */
 	int nocb_p_count_lazy;		/*  (approximate). */
-	wait_queue_head_t nocb_wq;	/* For nocb kthreads to sleep on. */
+	struct swait_head nocb_wq;	/* For nocb kthreads to sleep on. */
 	struct task_struct *nocb_kthread;
 	int nocb_defer_wakeup;		/* Defer wakeup of nocb_kthread. */
 
@@ -439,7 +435,7 @@
 	unsigned long gpnum;			/* Current gp number. */
 	unsigned long completed;		/* # of last completed gp. */
 	struct task_struct *gp_kthread;		/* Task for grace periods. */
-	wait_queue_head_t gp_wq;		/* Where GP task waits. */
+	struct swait_head gp_wq;		/* Where GP task waits. */
 	short gp_flags;				/* Commands for GP task. */
 	short gp_state;				/* GP kthread sleep state. */
 
@@ -570,10 +566,9 @@
 static void __init __rcu_init_preempt(void);
 static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags);
 static void rcu_preempt_boost_start_gp(struct rcu_node *rnp);
-static void invoke_rcu_callbacks_kthread(void);
 static bool rcu_is_callbacks_kthread(void);
+static void rcu_cpu_kthread_setup(unsigned int cpu);
 #ifdef CONFIG_RCU_BOOST
-static void rcu_preempt_do_callbacks(void);
 static int rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
 						 struct rcu_node *rnp);
 #endif /* #ifdef CONFIG_RCU_BOOST */
diff -Nur linux-3.18.12.orig/kernel/rcu/tree_plugin.h linux-3.18.12/kernel/rcu/tree_plugin.h
--- linux-3.18.12.orig/kernel/rcu/tree_plugin.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/rcu/tree_plugin.h	2015-04-26 13:32:22.443684003 -0500
@@ -24,12 +24,6 @@
  *	   Paul E. McKenney <paulmck@linux.vnet.ibm.com>
  */
 
-#include <linux/delay.h>
-#include <linux/gfp.h>
-#include <linux/oom.h>
-#include <linux/smpboot.h>
-#include "../time/tick-internal.h"
-
 #define RCU_KTHREAD_PRIO 1
 
 #ifdef CONFIG_RCU_BOOST
@@ -335,7 +329,7 @@
 	}
 
 	/* Hardware IRQ handlers cannot block, complain if they get here. */
-	if (WARN_ON_ONCE(in_irq() || in_serving_softirq())) {
+	if (WARN_ON_ONCE(preempt_count() & (HARDIRQ_MASK | SOFTIRQ_OFFSET))) {
 		local_irq_restore(flags);
 		return;
 	}
@@ -398,10 +392,8 @@
 
 #ifdef CONFIG_RCU_BOOST
 		/* Unboost if we were boosted. */
-		if (drop_boost_mutex) {
+		if (drop_boost_mutex)
 			rt_mutex_unlock(&rnp->boost_mtx);
-			complete(&rnp->boost_completion);
-		}
 #endif /* #ifdef CONFIG_RCU_BOOST */
 
 		/*
@@ -635,15 +627,6 @@
 		t->rcu_read_unlock_special.b.need_qs = true;
 }
 
-#ifdef CONFIG_RCU_BOOST
-
-static void rcu_preempt_do_callbacks(void)
-{
-	rcu_do_batch(&rcu_preempt_state, this_cpu_ptr(&rcu_preempt_data));
-}
-
-#endif /* #ifdef CONFIG_RCU_BOOST */
-
 /*
  * Queue a preemptible-RCU callback for invocation after a grace period.
  */
@@ -1072,6 +1055,19 @@
 
 #endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */
 
+/*
+ * If boosting, set rcuc kthreads to realtime priority.
+ */
+static void rcu_cpu_kthread_setup(unsigned int cpu)
+{
+#ifdef CONFIG_RCU_BOOST
+	struct sched_param sp;
+
+	sp.sched_priority = RCU_KTHREAD_PRIO;
+	sched_setscheduler_nocheck(current, SCHED_FIFO, &sp);
+#endif /* #ifdef CONFIG_RCU_BOOST */
+}
+
 #ifdef CONFIG_RCU_BOOST
 
 #include "../locking/rtmutex_common.h"
@@ -1103,16 +1099,6 @@
 
 #endif /* #else #ifdef CONFIG_RCU_TRACE */
 
-static void rcu_wake_cond(struct task_struct *t, int status)
-{
-	/*
-	 * If the thread is yielding, only wake it when this
-	 * is invoked from idle
-	 */
-	if (status != RCU_KTHREAD_YIELDING || is_idle_task(current))
-		wake_up_process(t);
-}
-
 /*
  * Carry out RCU priority boosting on the task indicated by ->exp_tasks
  * or ->boost_tasks, advancing the pointer to the next task in the
@@ -1175,15 +1161,11 @@
 	 */
 	t = container_of(tb, struct task_struct, rcu_node_entry);
 	rt_mutex_init_proxy_locked(&rnp->boost_mtx, t);
-	init_completion(&rnp->boost_completion);
 	raw_spin_unlock_irqrestore(&rnp->lock, flags);
 	/* Lock only for side effect: boosts task t's priority. */
 	rt_mutex_lock(&rnp->boost_mtx);
 	rt_mutex_unlock(&rnp->boost_mtx);  /* Then keep lockdep happy. */
 
-	/* Wait for boostee to be done w/boost_mtx before reinitializing. */
-	wait_for_completion(&rnp->boost_completion);
-
 	return ACCESS_ONCE(rnp->exp_tasks) != NULL ||
 	       ACCESS_ONCE(rnp->boost_tasks) != NULL;
 }
@@ -1261,23 +1243,6 @@
 }
 
 /*
- * Wake up the per-CPU kthread to invoke RCU callbacks.
- */
-static void invoke_rcu_callbacks_kthread(void)
-{
-	unsigned long flags;
-
-	local_irq_save(flags);
-	__this_cpu_write(rcu_cpu_has_work, 1);
-	if (__this_cpu_read(rcu_cpu_kthread_task) != NULL &&
-	    current != __this_cpu_read(rcu_cpu_kthread_task)) {
-		rcu_wake_cond(__this_cpu_read(rcu_cpu_kthread_task),
-			      __this_cpu_read(rcu_cpu_kthread_status));
-	}
-	local_irq_restore(flags);
-}
-
-/*
  * Is the current CPU running the RCU-callbacks kthread?
  * Caller must have preemption disabled.
  */
@@ -1332,67 +1297,6 @@
 	return 0;
 }
 
-static void rcu_kthread_do_work(void)
-{
-	rcu_do_batch(&rcu_sched_state, this_cpu_ptr(&rcu_sched_data));
-	rcu_do_batch(&rcu_bh_state, this_cpu_ptr(&rcu_bh_data));
-	rcu_preempt_do_callbacks();
-}
-
-static void rcu_cpu_kthread_setup(unsigned int cpu)
-{
-	struct sched_param sp;
-
-	sp.sched_priority = RCU_KTHREAD_PRIO;
-	sched_setscheduler_nocheck(current, SCHED_FIFO, &sp);
-}
-
-static void rcu_cpu_kthread_park(unsigned int cpu)
-{
-	per_cpu(rcu_cpu_kthread_status, cpu) = RCU_KTHREAD_OFFCPU;
-}
-
-static int rcu_cpu_kthread_should_run(unsigned int cpu)
-{
-	return __this_cpu_read(rcu_cpu_has_work);
-}
-
-/*
- * Per-CPU kernel thread that invokes RCU callbacks.  This replaces the
- * RCU softirq used in flavors and configurations of RCU that do not
- * support RCU priority boosting.
- */
-static void rcu_cpu_kthread(unsigned int cpu)
-{
-	unsigned int *statusp = this_cpu_ptr(&rcu_cpu_kthread_status);
-	char work, *workp = this_cpu_ptr(&rcu_cpu_has_work);
-	int spincnt;
-
-	for (spincnt = 0; spincnt < 10; spincnt++) {
-		trace_rcu_utilization(TPS("Start CPU kthread@rcu_wait"));
-		local_bh_disable();
-		*statusp = RCU_KTHREAD_RUNNING;
-		this_cpu_inc(rcu_cpu_kthread_loops);
-		local_irq_disable();
-		work = *workp;
-		*workp = 0;
-		local_irq_enable();
-		if (work)
-			rcu_kthread_do_work();
-		local_bh_enable();
-		if (*workp == 0) {
-			trace_rcu_utilization(TPS("End CPU kthread@rcu_wait"));
-			*statusp = RCU_KTHREAD_WAITING;
-			return;
-		}
-	}
-	*statusp = RCU_KTHREAD_YIELDING;
-	trace_rcu_utilization(TPS("Start CPU kthread@rcu_yield"));
-	schedule_timeout_interruptible(2);
-	trace_rcu_utilization(TPS("End CPU kthread@rcu_yield"));
-	*statusp = RCU_KTHREAD_WAITING;
-}
-
 /*
  * Set the per-rcu_node kthread's affinity to cover all CPUs that are
  * served by the rcu_node in question.  The CPU hotplug lock is still
@@ -1426,26 +1330,13 @@
 	free_cpumask_var(cm);
 }
 
-static struct smp_hotplug_thread rcu_cpu_thread_spec = {
-	.store			= &rcu_cpu_kthread_task,
-	.thread_should_run	= rcu_cpu_kthread_should_run,
-	.thread_fn		= rcu_cpu_kthread,
-	.thread_comm		= "rcuc/%u",
-	.setup			= rcu_cpu_kthread_setup,
-	.park			= rcu_cpu_kthread_park,
-};
-
 /*
  * Spawn boost kthreads -- called as soon as the scheduler is running.
  */
 static void __init rcu_spawn_boost_kthreads(void)
 {
 	struct rcu_node *rnp;
-	int cpu;
 
-	for_each_possible_cpu(cpu)
-		per_cpu(rcu_cpu_has_work, cpu) = 0;
-	BUG_ON(smpboot_register_percpu_thread(&rcu_cpu_thread_spec));
 	rnp = rcu_get_root(rcu_state_p);
 	(void)rcu_spawn_one_boost_kthread(rcu_state_p, rnp);
 	if (NUM_RCU_NODES > 1) {
@@ -1472,11 +1363,6 @@
 	raw_spin_unlock_irqrestore(&rnp->lock, flags);
 }
 
-static void invoke_rcu_callbacks_kthread(void)
-{
-	WARN_ON_ONCE(1);
-}
-
 static bool rcu_is_callbacks_kthread(void)
 {
 	return false;
@@ -1500,7 +1386,7 @@
 
 #endif /* #else #ifdef CONFIG_RCU_BOOST */
 
-#if !defined(CONFIG_RCU_FAST_NO_HZ)
+#if !defined(CONFIG_RCU_FAST_NO_HZ) || defined(CONFIG_PREEMPT_RT_FULL)
 
 /*
  * Check to see if any future RCU-related work will need to be done
@@ -1518,7 +1404,9 @@
 	return rcu_cpu_has_callbacks(cpu, NULL);
 }
 #endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */
+#endif /* !defined(CONFIG_RCU_FAST_NO_HZ) || defined(CONFIG_PREEMPT_RT_FULL) */
 
+#if !defined(CONFIG_RCU_FAST_NO_HZ)
 /*
  * Because we do not have RCU_FAST_NO_HZ, don't bother cleaning up
  * after it.
@@ -1615,6 +1503,8 @@
 	return cbs_ready;
 }
 
+#ifndef CONFIG_PREEMPT_RT_FULL
+
 /*
  * Allow the CPU to enter dyntick-idle mode unless it has callbacks ready
  * to invoke.  If the CPU has callbacks, try to advance them.  Tell the
@@ -1655,7 +1545,7 @@
 	return 0;
 }
 #endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */
-
+#endif /* #ifndef CONFIG_PREEMPT_RT_FULL */
 /*
  * Prepare a CPU for idle from an RCU perspective.  The first major task
  * is to sense whether nohz mode has been enabled or disabled via sysfs.
@@ -2001,7 +1891,7 @@
  */
 static void rcu_nocb_gp_cleanup(struct rcu_state *rsp, struct rcu_node *rnp)
 {
-	wake_up_all(&rnp->nocb_gp_wq[rnp->completed & 0x1]);
+	swait_wake_all(&rnp->nocb_gp_wq[rnp->completed & 0x1]);
 }
 
 /*
@@ -2019,8 +1909,8 @@
 
 static void rcu_init_one_nocb(struct rcu_node *rnp)
 {
-	init_waitqueue_head(&rnp->nocb_gp_wq[0]);
-	init_waitqueue_head(&rnp->nocb_gp_wq[1]);
+	init_swait_head(&rnp->nocb_gp_wq[0]);
+	init_swait_head(&rnp->nocb_gp_wq[1]);
 }
 
 #ifndef CONFIG_RCU_NOCB_CPU_ALL
@@ -2045,7 +1935,7 @@
 	if (ACCESS_ONCE(rdp_leader->nocb_leader_sleep) || force) {
 		/* Prior smp_mb__after_atomic() orders against prior enqueue. */
 		ACCESS_ONCE(rdp_leader->nocb_leader_sleep) = false;
-		wake_up(&rdp_leader->nocb_wq);
+		swait_wake(&rdp_leader->nocb_wq);
 	}
 }
 
@@ -2238,7 +2128,7 @@
 	 */
 	trace_rcu_future_gp(rnp, rdp, c, TPS("StartWait"));
 	for (;;) {
-		wait_event_interruptible(
+		swait_event_interruptible(
 			rnp->nocb_gp_wq[c & 0x1],
 			(d = ULONG_CMP_GE(ACCESS_ONCE(rnp->completed), c)));
 		if (likely(d))
@@ -2266,7 +2156,7 @@
 	/* Wait for callbacks to appear. */
 	if (!rcu_nocb_poll) {
 		trace_rcu_nocb_wake(my_rdp->rsp->name, my_rdp->cpu, "Sleep");
-		wait_event_interruptible(my_rdp->nocb_wq,
+		swait_event_interruptible(my_rdp->nocb_wq,
 				!ACCESS_ONCE(my_rdp->nocb_leader_sleep));
 		/* Memory barrier handled by smp_mb() calls below and repoll. */
 	} else if (firsttime) {
@@ -2347,7 +2237,7 @@
 			 * List was empty, wake up the follower.
 			 * Memory barriers supplied by atomic_long_add().
 			 */
-			wake_up(&rdp->nocb_wq);
+			swait_wake(&rdp->nocb_wq);
 		}
 	}
 
@@ -2368,7 +2258,7 @@
 		if (!rcu_nocb_poll) {
 			trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu,
 					    "FollowerSleep");
-			wait_event_interruptible(rdp->nocb_wq,
+			swait_event_interruptible(rdp->nocb_wq,
 						 ACCESS_ONCE(rdp->nocb_follower_head));
 		} else if (firsttime) {
 			/* Don't drown trace log with "Poll"! */
@@ -2539,7 +2429,7 @@
 static void __init rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp)
 {
 	rdp->nocb_tail = &rdp->nocb_head;
-	init_waitqueue_head(&rdp->nocb_wq);
+	init_swait_head(&rdp->nocb_wq);
 	rdp->nocb_follower_tail = &rdp->nocb_follower_head;
 }
 
diff -Nur linux-3.18.12.orig/kernel/rcu/update.c linux-3.18.12/kernel/rcu/update.c
--- linux-3.18.12.orig/kernel/rcu/update.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/rcu/update.c	2015-04-26 13:32:22.443684003 -0500
@@ -170,6 +170,7 @@
 }
 EXPORT_SYMBOL_GPL(rcu_read_lock_held);
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 /**
  * rcu_read_lock_bh_held() - might we be in RCU-bh read-side critical section?
  *
@@ -196,6 +197,7 @@
 	return in_softirq() || irqs_disabled();
 }
 EXPORT_SYMBOL_GPL(rcu_read_lock_bh_held);
+#endif
 
 #endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
 
diff -Nur linux-3.18.12.orig/kernel/relay.c linux-3.18.12/kernel/relay.c
--- linux-3.18.12.orig/kernel/relay.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/relay.c	2015-04-26 13:32:22.443684003 -0500
@@ -339,6 +339,10 @@
 {
 	struct rchan_buf *buf = (struct rchan_buf *)data;
 	wake_up_interruptible(&buf->read_wait);
+	/*
+	 * Stupid polling for now:
+	 */
+	mod_timer(&buf->timer, jiffies + 1);
 }
 
 /**
@@ -356,6 +360,7 @@
 		init_waitqueue_head(&buf->read_wait);
 		kref_init(&buf->kref);
 		setup_timer(&buf->timer, wakeup_readers, (unsigned long)buf);
+		mod_timer(&buf->timer, jiffies + 1);
 	} else
 		del_timer_sync(&buf->timer);
 
@@ -739,15 +744,6 @@
 		else
 			buf->early_bytes += buf->chan->subbuf_size -
 					    buf->padding[old_subbuf];
-		smp_mb();
-		if (waitqueue_active(&buf->read_wait))
-			/*
-			 * Calling wake_up_interruptible() from here
-			 * will deadlock if we happen to be logging
-			 * from the scheduler (trying to re-grab
-			 * rq->lock), so defer it.
-			 */
-			mod_timer(&buf->timer, jiffies + 1);
 	}
 
 	old = buf->data;
diff -Nur linux-3.18.12.orig/kernel/res_counter.c linux-3.18.12/kernel/res_counter.c
--- linux-3.18.12.orig/kernel/res_counter.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/res_counter.c	2015-04-26 13:32:22.443684003 -0500
@@ -59,7 +59,7 @@
 
 	r = ret = 0;
 	*limit_fail_at = NULL;
-	local_irq_save(flags);
+	local_irq_save_nort(flags);
 	for (c = counter; c != NULL; c = c->parent) {
 		spin_lock(&c->lock);
 		r = res_counter_charge_locked(c, val, force);
@@ -79,7 +79,7 @@
 			spin_unlock(&u->lock);
 		}
 	}
-	local_irq_restore(flags);
+	local_irq_restore_nort(flags);
 
 	return ret;
 }
@@ -104,7 +104,7 @@
 	struct res_counter *c;
 	u64 ret = 0;
 
-	local_irq_save(flags);
+	local_irq_save_nort(flags);
 	for (c = counter; c != top; c = c->parent) {
 		u64 r;
 		spin_lock(&c->lock);
@@ -113,7 +113,7 @@
 			ret = r;
 		spin_unlock(&c->lock);
 	}
-	local_irq_restore(flags);
+	local_irq_restore_nort(flags);
 	return ret;
 }
 
diff -Nur linux-3.18.12.orig/kernel/sched/completion.c linux-3.18.12/kernel/sched/completion.c
--- linux-3.18.12.orig/kernel/sched/completion.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/sched/completion.c	2015-04-26 13:32:22.443684003 -0500
@@ -30,10 +30,10 @@
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&x->wait.lock, flags);
+	raw_spin_lock_irqsave(&x->wait.lock, flags);
 	x->done++;
-	__wake_up_locked(&x->wait, TASK_NORMAL, 1);
-	spin_unlock_irqrestore(&x->wait.lock, flags);
+	__swait_wake_locked(&x->wait, TASK_NORMAL, 1);
+	raw_spin_unlock_irqrestore(&x->wait.lock, flags);
 }
 EXPORT_SYMBOL(complete);
 
@@ -50,10 +50,10 @@
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&x->wait.lock, flags);
+	raw_spin_lock_irqsave(&x->wait.lock, flags);
 	x->done += UINT_MAX/2;
-	__wake_up_locked(&x->wait, TASK_NORMAL, 0);
-	spin_unlock_irqrestore(&x->wait.lock, flags);
+	__swait_wake_locked(&x->wait, TASK_NORMAL, 0);
+	raw_spin_unlock_irqrestore(&x->wait.lock, flags);
 }
 EXPORT_SYMBOL(complete_all);
 
@@ -62,20 +62,20 @@
 		   long (*action)(long), long timeout, int state)
 {
 	if (!x->done) {
-		DECLARE_WAITQUEUE(wait, current);
+		DEFINE_SWAITER(wait);
 
-		__add_wait_queue_tail_exclusive(&x->wait, &wait);
+		swait_prepare_locked(&x->wait, &wait);
 		do {
 			if (signal_pending_state(state, current)) {
 				timeout = -ERESTARTSYS;
 				break;
 			}
 			__set_current_state(state);
-			spin_unlock_irq(&x->wait.lock);
+			raw_spin_unlock_irq(&x->wait.lock);
 			timeout = action(timeout);
-			spin_lock_irq(&x->wait.lock);
+			raw_spin_lock_irq(&x->wait.lock);
 		} while (!x->done && timeout);
-		__remove_wait_queue(&x->wait, &wait);
+		swait_finish_locked(&x->wait, &wait);
 		if (!x->done)
 			return timeout;
 	}
@@ -89,9 +89,9 @@
 {
 	might_sleep();
 
-	spin_lock_irq(&x->wait.lock);
+	raw_spin_lock_irq(&x->wait.lock);
 	timeout = do_wait_for_common(x, action, timeout, state);
-	spin_unlock_irq(&x->wait.lock);
+	raw_spin_unlock_irq(&x->wait.lock);
 	return timeout;
 }
 
@@ -267,12 +267,12 @@
 	unsigned long flags;
 	int ret = 1;
 
-	spin_lock_irqsave(&x->wait.lock, flags);
+	raw_spin_lock_irqsave(&x->wait.lock, flags);
 	if (!x->done)
 		ret = 0;
 	else
 		x->done--;
-	spin_unlock_irqrestore(&x->wait.lock, flags);
+	raw_spin_unlock_irqrestore(&x->wait.lock, flags);
 	return ret;
 }
 EXPORT_SYMBOL(try_wait_for_completion);
@@ -290,10 +290,10 @@
 	unsigned long flags;
 	int ret = 1;
 
-	spin_lock_irqsave(&x->wait.lock, flags);
+	raw_spin_lock_irqsave(&x->wait.lock, flags);
 	if (!x->done)
 		ret = 0;
-	spin_unlock_irqrestore(&x->wait.lock, flags);
+	raw_spin_unlock_irqrestore(&x->wait.lock, flags);
 	return ret;
 }
 EXPORT_SYMBOL(completion_done);
diff -Nur linux-3.18.12.orig/kernel/sched/core.c linux-3.18.12/kernel/sched/core.c
--- linux-3.18.12.orig/kernel/sched/core.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/sched/core.c	2015-04-26 13:32:22.443684003 -0500
@@ -280,7 +280,11 @@
  * Number of tasks to iterate in a single balance run.
  * Limited because this is done with IRQs disabled.
  */
+#ifndef CONFIG_PREEMPT_RT_FULL
 const_debug unsigned int sysctl_sched_nr_migrate = 32;
+#else
+const_debug unsigned int sysctl_sched_nr_migrate = 8;
+#endif
 
 /*
  * period over which we average the RT time consumption, measured
@@ -516,6 +520,7 @@
 
 	hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 	rq->hrtick_timer.function = hrtick;
+	rq->hrtick_timer.irqsafe = 1;
 }
 #else	/* CONFIG_SCHED_HRTICK */
 static inline void hrtick_clear(struct rq *rq)
@@ -627,6 +632,38 @@
 		trace_sched_wake_idle_without_ipi(cpu);
 }
 
+#ifdef CONFIG_PREEMPT_LAZY
+void resched_curr_lazy(struct rq *rq)
+{
+	struct task_struct *curr = rq->curr;
+	int cpu;
+
+	if (!sched_feat(PREEMPT_LAZY)) {
+		resched_curr(rq);
+		return;
+	}
+
+	lockdep_assert_held(&rq->lock);
+
+	if (test_tsk_need_resched(curr))
+		return;
+
+	if (test_tsk_need_resched_lazy(curr))
+		return;
+
+	set_tsk_need_resched_lazy(curr);
+
+	cpu = cpu_of(rq);
+	if (cpu == smp_processor_id())
+		return;
+
+	/* NEED_RESCHED_LAZY must be visible before we test polling */
+	smp_mb();
+	if (!tsk_is_polling(curr))
+		smp_send_reschedule(cpu);
+}
+#endif
+
 void resched_cpu(int cpu)
 {
 	struct rq *rq = cpu_rq(cpu);
@@ -650,12 +687,14 @@
  */
 int get_nohz_timer_target(int pinned)
 {
-	int cpu = smp_processor_id();
+	int cpu;
 	int i;
 	struct sched_domain *sd;
 
+	preempt_disable_rt();
+	cpu = smp_processor_id();
 	if (pinned || !get_sysctl_timer_migration() || !idle_cpu(cpu))
-		return cpu;
+		goto preempt_en_rt;
 
 	rcu_read_lock();
 	for_each_domain(cpu, sd) {
@@ -668,6 +707,8 @@
 	}
 unlock:
 	rcu_read_unlock();
+preempt_en_rt:
+	preempt_enable_rt();
 	return cpu;
 }
 /*
@@ -745,14 +786,29 @@
 #endif /* CONFIG_NO_HZ_COMMON */
 
 #ifdef CONFIG_NO_HZ_FULL
+
+static int ksoftirqd_running(void)
+{
+	struct task_struct *softirqd;
+
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT_FULL))
+		return 0;
+	softirqd = this_cpu_ksoftirqd();
+	if (softirqd && softirqd->on_rq)
+		return 1;
+	return 0;
+}
+
 bool sched_can_stop_tick(void)
 {
 	/*
 	 * More than one running task need preemption.
 	 * nr_running update is assumed to be visible
 	 * after IPI is sent from wakers.
+	 *
+	 * NOTE, RT: if ksoftirqd is awake, subtract it.
 	 */
-	if (this_rq()->nr_running > 1)
+	if (this_rq()->nr_running - ksoftirqd_running() > 1)
 		return false;
 
 	return true;
@@ -1198,6 +1254,18 @@
 
 static int migration_cpu_stop(void *data);
 
+static bool check_task_state(struct task_struct *p, long match_state)
+{
+	bool match = false;
+
+	raw_spin_lock_irq(&p->pi_lock);
+	if (p->state == match_state || p->saved_state == match_state)
+		match = true;
+	raw_spin_unlock_irq(&p->pi_lock);
+
+	return match;
+}
+
 /*
  * wait_task_inactive - wait for a thread to unschedule.
  *
@@ -1242,7 +1310,7 @@
 		 * is actually now running somewhere else!
 		 */
 		while (task_running(rq, p)) {
-			if (match_state && unlikely(p->state != match_state))
+			if (match_state && !check_task_state(p, match_state))
 				return 0;
 			cpu_relax();
 		}
@@ -1257,7 +1325,8 @@
 		running = task_running(rq, p);
 		queued = task_on_rq_queued(p);
 		ncsw = 0;
-		if (!match_state || p->state == match_state)
+		if (!match_state || p->state == match_state ||
+		    p->saved_state == match_state)
 			ncsw = p->nvcsw | LONG_MIN; /* sets MSB */
 		task_rq_unlock(rq, p, &flags);
 
@@ -1482,10 +1551,6 @@
 {
 	activate_task(rq, p, en_flags);
 	p->on_rq = TASK_ON_RQ_QUEUED;
-
-	/* if a worker is waking up, notify workqueue */
-	if (p->flags & PF_WQ_WORKER)
-		wq_worker_waking_up(p, cpu_of(rq));
 }
 
 /*
@@ -1699,8 +1764,27 @@
 	 */
 	smp_mb__before_spinlock();
 	raw_spin_lock_irqsave(&p->pi_lock, flags);
-	if (!(p->state & state))
+	if (!(p->state & state)) {
+		/*
+		 * The task might be running due to a spinlock sleeper
+		 * wakeup. Check the saved state and set it to running
+		 * if the wakeup condition is true.
+		 */
+		if (!(wake_flags & WF_LOCK_SLEEPER)) {
+			if (p->saved_state & state) {
+				p->saved_state = TASK_RUNNING;
+				success = 1;
+			}
+		}
 		goto out;
+	}
+
+	/*
+	 * If this is a regular wakeup, then we can unconditionally
+	 * clear the saved state of a "lock sleeper".
+	 */
+	if (!(wake_flags & WF_LOCK_SLEEPER))
+		p->saved_state = TASK_RUNNING;
 
 	success = 1; /* we're going to change ->state */
 	cpu = task_cpu(p);
@@ -1743,42 +1827,6 @@
 }
 
 /**
- * try_to_wake_up_local - try to wake up a local task with rq lock held
- * @p: the thread to be awakened
- *
- * Put @p on the run-queue if it's not already there. The caller must
- * ensure that this_rq() is locked, @p is bound to this_rq() and not
- * the current task.
- */
-static void try_to_wake_up_local(struct task_struct *p)
-{
-	struct rq *rq = task_rq(p);
-
-	if (WARN_ON_ONCE(rq != this_rq()) ||
-	    WARN_ON_ONCE(p == current))
-		return;
-
-	lockdep_assert_held(&rq->lock);
-
-	if (!raw_spin_trylock(&p->pi_lock)) {
-		raw_spin_unlock(&rq->lock);
-		raw_spin_lock(&p->pi_lock);
-		raw_spin_lock(&rq->lock);
-	}
-
-	if (!(p->state & TASK_NORMAL))
-		goto out;
-
-	if (!task_on_rq_queued(p))
-		ttwu_activate(rq, p, ENQUEUE_WAKEUP);
-
-	ttwu_do_wakeup(rq, p, 0);
-	ttwu_stat(p, smp_processor_id(), 0);
-out:
-	raw_spin_unlock(&p->pi_lock);
-}
-
-/**
  * wake_up_process - Wake up a specific process
  * @p: The process to be woken up.
  *
@@ -1792,11 +1840,23 @@
  */
 int wake_up_process(struct task_struct *p)
 {
-	WARN_ON(task_is_stopped_or_traced(p));
+	WARN_ON(__task_is_stopped_or_traced(p));
 	return try_to_wake_up(p, TASK_NORMAL, 0);
 }
 EXPORT_SYMBOL(wake_up_process);
 
+/**
+ * wake_up_lock_sleeper - Wake up a specific process blocked on a "sleeping lock"
+ * @p: The process to be woken up.
+ *
+ * Same as wake_up_process() above, but wake_flags=WF_LOCK_SLEEPER to indicate
+ * the nature of the wakeup.
+ */
+int wake_up_lock_sleeper(struct task_struct *p)
+{
+	return try_to_wake_up(p, TASK_ALL, WF_LOCK_SLEEPER);
+}
+
 int wake_up_state(struct task_struct *p, unsigned int state)
 {
 	return try_to_wake_up(p, state, 0);
@@ -1987,6 +2047,9 @@
 	p->on_cpu = 0;
 #endif
 	init_task_preempt_count(p);
+#ifdef CONFIG_HAVE_PREEMPT_LAZY
+	task_thread_info(p)->preempt_lazy_count = 0;
+#endif
 #ifdef CONFIG_SMP
 	plist_node_init(&p->pushable_tasks, MAX_PRIO);
 	RB_CLEAR_NODE(&p->pushable_dl_tasks);
@@ -2270,8 +2333,12 @@
 	finish_arch_post_lock_switch();
 
 	fire_sched_in_preempt_notifiers(current);
+	/*
+	 * We use mmdrop_delayed() here so we don't have to do the
+	 * full __mmdrop() when we are the last user.
+	 */
 	if (mm)
-		mmdrop(mm);
+		mmdrop_delayed(mm);
 	if (unlikely(prev_state == TASK_DEAD)) {
 		if (prev->sched_class->task_dead)
 			prev->sched_class->task_dead(prev);
@@ -2696,6 +2763,133 @@
 	schedstat_inc(this_rq(), sched_count);
 }
 
+#if defined(CONFIG_PREEMPT_RT_FULL) && defined(CONFIG_SMP)
+#define MIGRATE_DISABLE_SET_AFFIN	(1<<30) /* Can't make a negative */
+#define migrate_disabled_updated(p)	((p)->migrate_disable & MIGRATE_DISABLE_SET_AFFIN)
+#define migrate_disable_count(p)	((p)->migrate_disable & ~MIGRATE_DISABLE_SET_AFFIN)
+
+static inline void update_migrate_disable(struct task_struct *p)
+{
+	const struct cpumask *mask;
+
+	if (likely(!p->migrate_disable))
+		return;
+
+	/* Did we already update affinity? */
+	if (unlikely(migrate_disabled_updated(p)))
+		return;
+
+	/*
+	 * Since this is always current we can get away with only locking
+	 * rq->lock, the ->cpus_allowed value can normally only be changed
+	 * while holding both p->pi_lock and rq->lock, but seeing that this
+	 * is current, we cannot actually be waking up, so all code that
+	 * relies on serialization against p->pi_lock is out of scope.
+	 *
+	 * Having rq->lock serializes us against things like
+	 * set_cpus_allowed_ptr() that can still happen concurrently.
+	 */
+	mask = tsk_cpus_allowed(p);
+
+	if (p->sched_class->set_cpus_allowed)
+		p->sched_class->set_cpus_allowed(p, mask);
+	/* mask==cpumask_of(task_cpu(p)) which has a cpumask_weight==1 */
+	p->nr_cpus_allowed = 1;
+
+	/* Let migrate_enable know to fix things back up */
+	p->migrate_disable |= MIGRATE_DISABLE_SET_AFFIN;
+}
+
+void migrate_disable(void)
+{
+	struct task_struct *p = current;
+
+	if (in_atomic()) {
+#ifdef CONFIG_SCHED_DEBUG
+		p->migrate_disable_atomic++;
+#endif
+		return;
+	}
+
+#ifdef CONFIG_SCHED_DEBUG
+	if (unlikely(p->migrate_disable_atomic)) {
+		tracing_off();
+		WARN_ON_ONCE(1);
+	}
+#endif
+
+	if (p->migrate_disable) {
+		p->migrate_disable++;
+		return;
+	}
+
+	preempt_disable();
+	preempt_lazy_disable();
+	pin_current_cpu();
+	p->migrate_disable = 1;
+	preempt_enable();
+}
+EXPORT_SYMBOL(migrate_disable);
+
+void migrate_enable(void)
+{
+	struct task_struct *p = current;
+	const struct cpumask *mask;
+	unsigned long flags;
+	struct rq *rq;
+
+	if (in_atomic()) {
+#ifdef CONFIG_SCHED_DEBUG
+		p->migrate_disable_atomic--;
+#endif
+		return;
+	}
+
+#ifdef CONFIG_SCHED_DEBUG
+	if (unlikely(p->migrate_disable_atomic)) {
+		tracing_off();
+		WARN_ON_ONCE(1);
+	}
+#endif
+	WARN_ON_ONCE(p->migrate_disable <= 0);
+
+	if (migrate_disable_count(p) > 1) {
+		p->migrate_disable--;
+		return;
+	}
+
+	preempt_disable();
+	if (unlikely(migrate_disabled_updated(p))) {
+		/*
+		 * Undo whatever update_migrate_disable() did, also see there
+		 * about locking.
+		 */
+		rq = this_rq();
+		raw_spin_lock_irqsave(&rq->lock, flags);
+
+		/*
+		 * Clearing migrate_disable causes tsk_cpus_allowed to
+		 * show the tasks original cpu affinity.
+		 */
+		p->migrate_disable = 0;
+		mask = tsk_cpus_allowed(p);
+		if (p->sched_class->set_cpus_allowed)
+			p->sched_class->set_cpus_allowed(p, mask);
+		p->nr_cpus_allowed = cpumask_weight(mask);
+		raw_spin_unlock_irqrestore(&rq->lock, flags);
+	} else
+		p->migrate_disable = 0;
+
+	unpin_current_cpu();
+	preempt_enable();
+	preempt_lazy_enable();
+}
+EXPORT_SYMBOL(migrate_enable);
+#else
+static inline void update_migrate_disable(struct task_struct *p) { }
+#define migrate_disabled_updated(p)		0
+#endif
+
 /*
  * Pick up the highest-prio task:
  */
@@ -2799,6 +2993,8 @@
 	smp_mb__before_spinlock();
 	raw_spin_lock_irq(&rq->lock);
 
+	update_migrate_disable(prev);
+
 	switch_count = &prev->nivcsw;
 	if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
 		if (unlikely(signal_pending_state(prev->state, prev))) {
@@ -2806,19 +3002,6 @@
 		} else {
 			deactivate_task(rq, prev, DEQUEUE_SLEEP);
 			prev->on_rq = 0;
-
-			/*
-			 * If a worker went to sleep, notify and ask workqueue
-			 * whether it wants to wake up a task to maintain
-			 * concurrency.
-			 */
-			if (prev->flags & PF_WQ_WORKER) {
-				struct task_struct *to_wakeup;
-
-				to_wakeup = wq_worker_sleeping(prev, cpu);
-				if (to_wakeup)
-					try_to_wake_up_local(to_wakeup);
-			}
 		}
 		switch_count = &prev->nvcsw;
 	}
@@ -2828,6 +3011,7 @@
 
 	next = pick_next_task(rq, prev);
 	clear_tsk_need_resched(prev);
+	clear_tsk_need_resched_lazy(prev);
 	clear_preempt_need_resched();
 	rq->skip_clock_update = 0;
 
@@ -2857,9 +3041,20 @@
 
 static inline void sched_submit_work(struct task_struct *tsk)
 {
-	if (!tsk->state || tsk_is_pi_blocked(tsk))
+	if (!tsk->state)
 		return;
 	/*
+	 * If a worker went to sleep, notify and ask workqueue whether
+	 * it wants to wake up a task to maintain concurrency.
+	 */
+	if (tsk->flags & PF_WQ_WORKER)
+		wq_worker_sleeping(tsk);
+
+
+	if (tsk_is_pi_blocked(tsk))
+		return;
+
+	/*
 	 * If we are going to sleep and we have plugged IO queued,
 	 * make sure to submit it to avoid deadlocks.
 	 */
@@ -2867,12 +3062,19 @@
 		blk_schedule_flush_plug(tsk);
 }
 
+static inline void sched_update_worker(struct task_struct *tsk)
+{
+	if (tsk->flags & PF_WQ_WORKER)
+		wq_worker_running(tsk);
+}
+
 asmlinkage __visible void __sched schedule(void)
 {
 	struct task_struct *tsk = current;
 
 	sched_submit_work(tsk);
 	__schedule();
+	sched_update_worker(tsk);
 }
 EXPORT_SYMBOL(schedule);
 
@@ -2922,9 +3124,26 @@
 	if (likely(!preemptible()))
 		return;
 
+#ifdef CONFIG_PREEMPT_LAZY
+	/*
+	 * Check for lazy preemption
+	 */
+	if (current_thread_info()->preempt_lazy_count &&
+			!test_thread_flag(TIF_NEED_RESCHED))
+		return;
+#endif
 	do {
 		__preempt_count_add(PREEMPT_ACTIVE);
+		/*
+		 * The add/subtract must not be traced by the function
+		 * tracer. But we still want to account for the
+		 * preempt off latency tracer. Since the _notrace versions
+		 * of add/subtract skip the accounting for latency tracer
+		 * we must force it manually.
+		 */
+		start_critical_timings();
 		__schedule();
+		stop_critical_timings();
 		__preempt_count_sub(PREEMPT_ACTIVE);
 
 		/*
@@ -3097,6 +3316,8 @@
 	} else {
 		if (dl_prio(oldprio))
 			p->dl.dl_boosted = 0;
+		if (rt_prio(oldprio))
+			p->rt.timeout = 0;
 		p->sched_class = &fair_sched_class;
 	}
 
@@ -4234,9 +4455,16 @@
 
 static void __cond_resched(void)
 {
-	__preempt_count_add(PREEMPT_ACTIVE);
-	__schedule();
-	__preempt_count_sub(PREEMPT_ACTIVE);
+	do {
+		__preempt_count_add(PREEMPT_ACTIVE);
+		__schedule();
+		__preempt_count_sub(PREEMPT_ACTIVE);
+		/*
+		 * Check again in case we missed a preemption
+		 * opportunity between schedule and now.
+		 */
+		barrier();
+	} while (need_resched());
 }
 
 int __sched _cond_resched(void)
@@ -4277,6 +4505,7 @@
 }
 EXPORT_SYMBOL(__cond_resched_lock);
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 int __sched __cond_resched_softirq(void)
 {
 	BUG_ON(!in_softirq());
@@ -4290,6 +4519,7 @@
 	return 0;
 }
 EXPORT_SYMBOL(__cond_resched_softirq);
+#endif
 
 /**
  * yield - yield the current processor to other threads.
@@ -4651,7 +4881,9 @@
 
 	/* Set the preempt count _outside_ the spinlocks! */
 	init_idle_preempt_count(idle, cpu);
-
+#ifdef CONFIG_HAVE_PREEMPT_LAZY
+	task_thread_info(idle)->preempt_lazy_count = 0;
+#endif
 	/*
 	 * The idle tasks have their own, simple scheduling class:
 	 */
@@ -4693,11 +4925,91 @@
 
 void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
 {
-	if (p->sched_class && p->sched_class->set_cpus_allowed)
-		p->sched_class->set_cpus_allowed(p, new_mask);
+	if (!migrate_disabled_updated(p)) {
+		if (p->sched_class && p->sched_class->set_cpus_allowed)
+			p->sched_class->set_cpus_allowed(p, new_mask);
+		p->nr_cpus_allowed = cpumask_weight(new_mask);
+	}
 
 	cpumask_copy(&p->cpus_allowed, new_mask);
-	p->nr_cpus_allowed = cpumask_weight(new_mask);
+}
+
+static DEFINE_PER_CPU(struct cpumask, sched_cpumasks);
+static DEFINE_MUTEX(sched_down_mutex);
+static cpumask_t sched_down_cpumask;
+
+void tell_sched_cpu_down_begin(int cpu)
+{
+	mutex_lock(&sched_down_mutex);
+	cpumask_set_cpu(cpu, &sched_down_cpumask);
+	mutex_unlock(&sched_down_mutex);
+}
+
+void tell_sched_cpu_down_done(int cpu)
+{
+	mutex_lock(&sched_down_mutex);
+	cpumask_clear_cpu(cpu, &sched_down_cpumask);
+	mutex_unlock(&sched_down_mutex);
+}
+
+/**
+ * migrate_me - try to move the current task off this cpu
+ *
+ * Used by the pin_current_cpu() code to try to get tasks
+ * to move off the current CPU as it is going down.
+ * It will only move the task if the task isn't pinned to
+ * the CPU (with migrate_disable, affinity or NO_SETAFFINITY)
+ * and the task has to be in a RUNNING state. Otherwise the
+ * movement of the task will wake it up (change its state
+ * to running) when the task did not expect it.
+ *
+ * Returns 1 if it succeeded in moving the current task
+ *         0 otherwise.
+ */
+int migrate_me(void)
+{
+	struct task_struct *p = current;
+	struct migration_arg arg;
+	struct cpumask *cpumask;
+	struct cpumask *mask;
+	unsigned long flags;
+	unsigned int dest_cpu;
+	struct rq *rq;
+
+	/*
+	 * We can not migrate tasks bounded to a CPU or tasks not
+	 * running. The movement of the task will wake it up.
+	 */
+	if (p->flags & PF_NO_SETAFFINITY || p->state)
+		return 0;
+
+	mutex_lock(&sched_down_mutex);
+	rq = task_rq_lock(p, &flags);
+
+	cpumask = &__get_cpu_var(sched_cpumasks);
+	mask = &p->cpus_allowed;
+
+	cpumask_andnot(cpumask, mask, &sched_down_cpumask);
+
+	if (!cpumask_weight(cpumask)) {
+		/* It's only on this CPU? */
+		task_rq_unlock(rq, p, &flags);
+		mutex_unlock(&sched_down_mutex);
+		return 0;
+	}
+
+	dest_cpu = cpumask_any_and(cpu_active_mask, cpumask);
+
+	arg.task = p;
+	arg.dest_cpu = dest_cpu;
+
+	task_rq_unlock(rq, p, &flags);
+
+	stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg);
+	tlb_migrate_finish(p->mm);
+	mutex_unlock(&sched_down_mutex);
+
+	return 1;
 }
 
 /*
@@ -4743,7 +5055,7 @@
 	do_set_cpus_allowed(p, new_mask);
 
 	/* Can the task run on the task's current CPU? If so, we're done */
-	if (cpumask_test_cpu(task_cpu(p), new_mask))
+	if (cpumask_test_cpu(task_cpu(p), new_mask) || __migrate_disabled(p))
 		goto out;
 
 	dest_cpu = cpumask_any_and(cpu_active_mask, new_mask);
@@ -4883,6 +5195,8 @@
 
 #ifdef CONFIG_HOTPLUG_CPU
 
+static DEFINE_PER_CPU(struct mm_struct *, idle_last_mm);
+
 /*
  * Ensures that the idle task is using init_mm right before its cpu goes
  * offline.
@@ -4897,7 +5211,11 @@
 		switch_mm(mm, &init_mm, current);
 		finish_arch_post_lock_switch();
 	}
-	mmdrop(mm);
+	/*
+	 * Defer the cleanup to an alive cpu. On RT we can neither
+	 * call mmdrop() nor mmdrop_delayed() from here.
+	 */
+	per_cpu(idle_last_mm, smp_processor_id()) = mm;
 }
 
 /*
@@ -5240,6 +5558,10 @@
 
 	case CPU_DEAD:
 		calc_load_migrate(rq);
+		if (per_cpu(idle_last_mm, cpu)) {
+			mmdrop(per_cpu(idle_last_mm, cpu));
+			per_cpu(idle_last_mm, cpu) = NULL;
+		}
 		break;
 #endif
 	}
@@ -7181,7 +7503,8 @@
 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
 static inline int preempt_count_equals(int preempt_offset)
 {
-	int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth();
+	int nested = (preempt_count() & ~PREEMPT_ACTIVE) +
+		sched_rcu_preempt_depth();
 
 	return (nested == preempt_offset);
 }
diff -Nur linux-3.18.12.orig/kernel/sched/cputime.c linux-3.18.12/kernel/sched/cputime.c
--- linux-3.18.12.orig/kernel/sched/cputime.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/sched/cputime.c	2015-04-26 13:32:22.443684003 -0500
@@ -675,37 +675,45 @@
 
 void vtime_account_system(struct task_struct *tsk)
 {
-	write_seqlock(&tsk->vtime_seqlock);
+	raw_spin_lock(&tsk->vtime_lock);
+	write_seqcount_begin(&tsk->vtime_seq);
 	__vtime_account_system(tsk);
-	write_sequnlock(&tsk->vtime_seqlock);
+	write_seqcount_end(&tsk->vtime_seq);
+	raw_spin_unlock(&tsk->vtime_lock);
 }
 
 void vtime_gen_account_irq_exit(struct task_struct *tsk)
 {
-	write_seqlock(&tsk->vtime_seqlock);
+	raw_spin_lock(&tsk->vtime_lock);
+	write_seqcount_begin(&tsk->vtime_seq);
 	__vtime_account_system(tsk);
 	if (context_tracking_in_user())
 		tsk->vtime_snap_whence = VTIME_USER;
-	write_sequnlock(&tsk->vtime_seqlock);
+	write_seqcount_end(&tsk->vtime_seq);
+	raw_spin_unlock(&tsk->vtime_lock);
 }
 
 void vtime_account_user(struct task_struct *tsk)
 {
 	cputime_t delta_cpu;
 
-	write_seqlock(&tsk->vtime_seqlock);
+	raw_spin_lock(&tsk->vtime_lock);
+	write_seqcount_begin(&tsk->vtime_seq);
 	delta_cpu = get_vtime_delta(tsk);
 	tsk->vtime_snap_whence = VTIME_SYS;
 	account_user_time(tsk, delta_cpu, cputime_to_scaled(delta_cpu));
-	write_sequnlock(&tsk->vtime_seqlock);
+	write_seqcount_end(&tsk->vtime_seq);
+	raw_spin_unlock(&tsk->vtime_lock);
 }
 
 void vtime_user_enter(struct task_struct *tsk)
 {
-	write_seqlock(&tsk->vtime_seqlock);
+	raw_spin_lock(&tsk->vtime_lock);
+	write_seqcount_begin(&tsk->vtime_seq);
 	__vtime_account_system(tsk);
 	tsk->vtime_snap_whence = VTIME_USER;
-	write_sequnlock(&tsk->vtime_seqlock);
+	write_seqcount_end(&tsk->vtime_seq);
+	raw_spin_unlock(&tsk->vtime_lock);
 }
 
 void vtime_guest_enter(struct task_struct *tsk)
@@ -717,19 +725,23 @@
 	 * synchronization against the reader (task_gtime())
 	 * that can thus safely catch up with a tickless delta.
 	 */
-	write_seqlock(&tsk->vtime_seqlock);
+	raw_spin_lock(&tsk->vtime_lock);
+	write_seqcount_begin(&tsk->vtime_seq);
 	__vtime_account_system(tsk);
 	current->flags |= PF_VCPU;
-	write_sequnlock(&tsk->vtime_seqlock);
+	write_seqcount_end(&tsk->vtime_seq);
+	raw_spin_unlock(&tsk->vtime_lock);
 }
 EXPORT_SYMBOL_GPL(vtime_guest_enter);
 
 void vtime_guest_exit(struct task_struct *tsk)
 {
-	write_seqlock(&tsk->vtime_seqlock);
+	raw_spin_lock(&tsk->vtime_lock);
+	write_seqcount_begin(&tsk->vtime_seq);
 	__vtime_account_system(tsk);
 	current->flags &= ~PF_VCPU;
-	write_sequnlock(&tsk->vtime_seqlock);
+	write_seqcount_end(&tsk->vtime_seq);
+	raw_spin_unlock(&tsk->vtime_lock);
 }
 EXPORT_SYMBOL_GPL(vtime_guest_exit);
 
@@ -742,24 +754,30 @@
 
 void arch_vtime_task_switch(struct task_struct *prev)
 {
-	write_seqlock(&prev->vtime_seqlock);
+	raw_spin_lock(&prev->vtime_lock);
+	write_seqcount_begin(&prev->vtime_seq);
 	prev->vtime_snap_whence = VTIME_SLEEPING;
-	write_sequnlock(&prev->vtime_seqlock);
+	write_seqcount_end(&prev->vtime_seq);
+	raw_spin_unlock(&prev->vtime_lock);
 
-	write_seqlock(&current->vtime_seqlock);
+	raw_spin_lock(&current->vtime_lock);
+	write_seqcount_begin(&current->vtime_seq);
 	current->vtime_snap_whence = VTIME_SYS;
 	current->vtime_snap = sched_clock_cpu(smp_processor_id());
-	write_sequnlock(&current->vtime_seqlock);
+	write_seqcount_end(&current->vtime_seq);
+	raw_spin_unlock(&current->vtime_lock);
 }
 
 void vtime_init_idle(struct task_struct *t, int cpu)
 {
 	unsigned long flags;
 
-	write_seqlock_irqsave(&t->vtime_seqlock, flags);
+	raw_spin_lock_irqsave(&t->vtime_lock, flags);
+	write_seqcount_begin(&t->vtime_seq);
 	t->vtime_snap_whence = VTIME_SYS;
 	t->vtime_snap = sched_clock_cpu(cpu);
-	write_sequnlock_irqrestore(&t->vtime_seqlock, flags);
+	write_seqcount_end(&t->vtime_seq);
+	raw_spin_unlock_irqrestore(&t->vtime_lock, flags);
 }
 
 cputime_t task_gtime(struct task_struct *t)
@@ -768,13 +786,13 @@
 	cputime_t gtime;
 
 	do {
-		seq = read_seqbegin(&t->vtime_seqlock);
+		seq = read_seqcount_begin(&t->vtime_seq);
 
 		gtime = t->gtime;
 		if (t->flags & PF_VCPU)
 			gtime += vtime_delta(t);
 
-	} while (read_seqretry(&t->vtime_seqlock, seq));
+	} while (read_seqcount_retry(&t->vtime_seq, seq));
 
 	return gtime;
 }
@@ -797,7 +815,7 @@
 		*udelta = 0;
 		*sdelta = 0;
 
-		seq = read_seqbegin(&t->vtime_seqlock);
+		seq = read_seqcount_begin(&t->vtime_seq);
 
 		if (u_dst)
 			*u_dst = *u_src;
@@ -821,7 +839,7 @@
 			if (t->vtime_snap_whence == VTIME_SYS)
 				*sdelta = delta;
 		}
-	} while (read_seqretry(&t->vtime_seqlock, seq));
+	} while (read_seqcount_retry(&t->vtime_seq, seq));
 }
 
 
diff -Nur linux-3.18.12.orig/kernel/sched/deadline.c linux-3.18.12/kernel/sched/deadline.c
--- linux-3.18.12.orig/kernel/sched/deadline.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/sched/deadline.c	2015-04-26 13:32:22.447684003 -0500
@@ -570,6 +570,7 @@
 
 	hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 	timer->function = dl_task_timer;
+	timer->irqsafe = 1;
 }
 
 static
diff -Nur linux-3.18.12.orig/kernel/sched/debug.c linux-3.18.12/kernel/sched/debug.c
--- linux-3.18.12.orig/kernel/sched/debug.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/sched/debug.c	2015-04-26 13:32:22.447684003 -0500
@@ -256,6 +256,9 @@
 	P(rt_throttled);
 	PN(rt_time);
 	PN(rt_runtime);
+#ifdef CONFIG_SMP
+	P(rt_nr_migratory);
+#endif
 
 #undef PN
 #undef P
@@ -634,6 +637,10 @@
 #endif
 	P(policy);
 	P(prio);
+#ifdef CONFIG_PREEMPT_RT_FULL
+	P(migrate_disable);
+#endif
+	P(nr_cpus_allowed);
 #undef PN
 #undef __PN
 #undef P
diff -Nur linux-3.18.12.orig/kernel/sched/fair.c linux-3.18.12/kernel/sched/fair.c
--- linux-3.18.12.orig/kernel/sched/fair.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/sched/fair.c	2015-04-26 13:32:22.447684003 -0500
@@ -2951,7 +2951,7 @@
 	ideal_runtime = sched_slice(cfs_rq, curr);
 	delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime;
 	if (delta_exec > ideal_runtime) {
-		resched_curr(rq_of(cfs_rq));
+		resched_curr_lazy(rq_of(cfs_rq));
 		/*
 		 * The current task ran long enough, ensure it doesn't get
 		 * re-elected due to buddy favours.
@@ -2975,7 +2975,7 @@
 		return;
 
 	if (delta > ideal_runtime)
-		resched_curr(rq_of(cfs_rq));
+		resched_curr_lazy(rq_of(cfs_rq));
 }
 
 static void
@@ -3115,7 +3115,7 @@
 	 * validating it and just reschedule.
 	 */
 	if (queued) {
-		resched_curr(rq_of(cfs_rq));
+		resched_curr_lazy(rq_of(cfs_rq));
 		return;
 	}
 	/*
@@ -3306,7 +3306,7 @@
 	 * hierarchy can be throttled
 	 */
 	if (!assign_cfs_rq_runtime(cfs_rq) && likely(cfs_rq->curr))
-		resched_curr(rq_of(cfs_rq));
+		resched_curr_lazy(rq_of(cfs_rq));
 }
 
 static __always_inline
@@ -3925,7 +3925,7 @@
 
 		if (delta < 0) {
 			if (rq->curr == p)
-				resched_curr(rq);
+				resched_curr_lazy(rq);
 			return;
 		}
 		hrtick_start(rq, delta);
@@ -4792,7 +4792,7 @@
 	return;
 
 preempt:
-	resched_curr(rq);
+	resched_curr_lazy(rq);
 	/*
 	 * Only set the backward buddy when the current task is still
 	 * on the rq. This can happen when a wakeup gets interleaved
@@ -7576,7 +7576,7 @@
 		 * 'current' within the tree based on its new key value.
 		 */
 		swap(curr->vruntime, se->vruntime);
-		resched_curr(rq);
+		resched_curr_lazy(rq);
 	}
 
 	se->vruntime -= cfs_rq->min_vruntime;
@@ -7601,7 +7601,7 @@
 	 */
 	if (rq->curr == p) {
 		if (p->prio > oldprio)
-			resched_curr(rq);
+			resched_curr_lazy(rq);
 	} else
 		check_preempt_curr(rq, p, 0);
 }
diff -Nur linux-3.18.12.orig/kernel/sched/features.h linux-3.18.12/kernel/sched/features.h
--- linux-3.18.12.orig/kernel/sched/features.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/sched/features.h	2015-04-26 13:32:22.447684003 -0500
@@ -50,12 +50,18 @@
  */
 SCHED_FEAT(NONTASK_CAPACITY, true)
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+SCHED_FEAT(TTWU_QUEUE, false)
+# ifdef CONFIG_PREEMPT_LAZY
+SCHED_FEAT(PREEMPT_LAZY, true)
+# endif
+#else
 /*
  * Queue remote wakeups on the target CPU and process them
  * using the scheduler IPI. Reduces rq->lock contention/bounces.
  */
 SCHED_FEAT(TTWU_QUEUE, true)
-
+#endif
 SCHED_FEAT(FORCE_SD_OVERLAP, false)
 SCHED_FEAT(RT_RUNTIME_SHARE, true)
 SCHED_FEAT(LB_MIN, false)
diff -Nur linux-3.18.12.orig/kernel/sched/Makefile linux-3.18.12/kernel/sched/Makefile
--- linux-3.18.12.orig/kernel/sched/Makefile	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/sched/Makefile	2015-04-26 13:32:22.443684003 -0500
@@ -13,7 +13,7 @@
 
 obj-y += core.o proc.o clock.o cputime.o
 obj-y += idle_task.o fair.o rt.o deadline.o stop_task.o
-obj-y += wait.o completion.o idle.o
+obj-y += wait.o wait-simple.o work-simple.o completion.o idle.o
 obj-$(CONFIG_SMP) += cpupri.o cpudeadline.o
 obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o
 obj-$(CONFIG_SCHEDSTATS) += stats.o
diff -Nur linux-3.18.12.orig/kernel/sched/rt.c linux-3.18.12/kernel/sched/rt.c
--- linux-3.18.12.orig/kernel/sched/rt.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/sched/rt.c	2015-04-26 13:32:22.447684003 -0500
@@ -43,6 +43,7 @@
 
 	hrtimer_init(&rt_b->rt_period_timer,
 			CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	rt_b->rt_period_timer.irqsafe = 1;
 	rt_b->rt_period_timer.function = sched_rt_period_timer;
 }
 
diff -Nur linux-3.18.12.orig/kernel/sched/sched.h linux-3.18.12/kernel/sched/sched.h
--- linux-3.18.12.orig/kernel/sched/sched.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/sched/sched.h	2015-04-26 13:32:22.447684003 -0500
@@ -1018,6 +1018,7 @@
 #define WF_SYNC		0x01		/* waker goes to sleep after wakeup */
 #define WF_FORK		0x02		/* child wakeup after fork */
 #define WF_MIGRATED	0x4		/* internal use, task got migrated */
+#define WF_LOCK_SLEEPER	0x08		/* wakeup spinlock "sleeper" */
 
 /*
  * To aid in avoiding the subversion of "niceness" due to uneven distribution
@@ -1210,6 +1211,15 @@
 extern void resched_curr(struct rq *rq);
 extern void resched_cpu(int cpu);
 
+#ifdef CONFIG_PREEMPT_LAZY
+extern void resched_curr_lazy(struct rq *rq);
+#else
+static inline void resched_curr_lazy(struct rq *rq)
+{
+	resched_curr(rq);
+}
+#endif
+
 extern struct rt_bandwidth def_rt_bandwidth;
 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime);
 
diff -Nur linux-3.18.12.orig/kernel/sched/wait-simple.c linux-3.18.12/kernel/sched/wait-simple.c
--- linux-3.18.12.orig/kernel/sched/wait-simple.c	1969-12-31 18:00:00.000000000 -0600
+++ linux-3.18.12/kernel/sched/wait-simple.c	2015-04-26 13:32:22.447684003 -0500
@@ -0,0 +1,115 @@
+/*
+ * Simple waitqueues without fancy flags and callbacks
+ *
+ * (C) 2011 Thomas Gleixner <tglx@linutronix.de>
+ *
+ * Based on kernel/wait.c
+ *
+ * For licencing details see kernel-base/COPYING
+ */
+#include <linux/init.h>
+#include <linux/export.h>
+#include <linux/sched.h>
+#include <linux/wait-simple.h>
+
+/* Adds w to head->list. Must be called with head->lock locked. */
+static inline void __swait_enqueue(struct swait_head *head, struct swaiter *w)
+{
+	list_add(&w->node, &head->list);
+	/* We can't let the condition leak before the setting of head */
+	smp_mb();
+}
+
+/* Removes w from head->list. Must be called with head->lock locked. */
+static inline void __swait_dequeue(struct swaiter *w)
+{
+	list_del_init(&w->node);
+}
+
+void __init_swait_head(struct swait_head *head, struct lock_class_key *key)
+{
+	raw_spin_lock_init(&head->lock);
+	lockdep_set_class(&head->lock, key);
+	INIT_LIST_HEAD(&head->list);
+}
+EXPORT_SYMBOL(__init_swait_head);
+
+void swait_prepare_locked(struct swait_head *head, struct swaiter *w)
+{
+	w->task = current;
+	if (list_empty(&w->node))
+		__swait_enqueue(head, w);
+}
+
+void swait_prepare(struct swait_head *head, struct swaiter *w, int state)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&head->lock, flags);
+	swait_prepare_locked(head, w);
+	__set_current_state(state);
+	raw_spin_unlock_irqrestore(&head->lock, flags);
+}
+EXPORT_SYMBOL(swait_prepare);
+
+void swait_finish_locked(struct swait_head *head, struct swaiter *w)
+{
+	__set_current_state(TASK_RUNNING);
+	if (w->task)
+		__swait_dequeue(w);
+}
+
+void swait_finish(struct swait_head *head, struct swaiter *w)
+{
+	unsigned long flags;
+
+	__set_current_state(TASK_RUNNING);
+	if (w->task) {
+		raw_spin_lock_irqsave(&head->lock, flags);
+		__swait_dequeue(w);
+		raw_spin_unlock_irqrestore(&head->lock, flags);
+	}
+}
+EXPORT_SYMBOL(swait_finish);
+
+unsigned int
+__swait_wake_locked(struct swait_head *head, unsigned int state, unsigned int num)
+{
+	struct swaiter *curr, *next;
+	int woken = 0;
+
+	list_for_each_entry_safe(curr, next, &head->list, node) {
+		if (wake_up_state(curr->task, state)) {
+			__swait_dequeue(curr);
+			/*
+			 * The waiting task can free the waiter as
+			 * soon as curr->task = NULL is written,
+			 * without taking any locks. A memory barrier
+			 * is required here to prevent the following
+			 * store to curr->task from getting ahead of
+			 * the dequeue operation.
+			 */
+			smp_wmb();
+			curr->task = NULL;
+			if (++woken == num)
+				break;
+		}
+	}
+	return woken;
+}
+
+unsigned int
+__swait_wake(struct swait_head *head, unsigned int state, unsigned int num)
+{
+	unsigned long flags;
+	int woken;
+
+	if (!swaitqueue_active(head))
+		return 0;
+
+	raw_spin_lock_irqsave(&head->lock, flags);
+	woken = __swait_wake_locked(head, state, num);
+	raw_spin_unlock_irqrestore(&head->lock, flags);
+	return woken;
+}
+EXPORT_SYMBOL(__swait_wake);
diff -Nur linux-3.18.12.orig/kernel/sched/work-simple.c linux-3.18.12/kernel/sched/work-simple.c
--- linux-3.18.12.orig/kernel/sched/work-simple.c	1969-12-31 18:00:00.000000000 -0600
+++ linux-3.18.12/kernel/sched/work-simple.c	2015-04-26 13:32:22.447684003 -0500
@@ -0,0 +1,172 @@
+/*
+ * Copyright (C) 2014 BMW Car IT GmbH, Daniel Wagner daniel.wagner@bmw-carit.de
+ *
+ * Provides a framework for enqueuing callbacks from irq context
+ * PREEMPT_RT_FULL safe. The callbacks are executed in kthread context.
+ */
+
+#include <linux/wait-simple.h>
+#include <linux/work-simple.h>
+#include <linux/kthread.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#define SWORK_EVENT_PENDING     (1 << 0)
+
+static DEFINE_MUTEX(worker_mutex);
+static struct sworker *glob_worker;
+
+struct sworker {
+	struct list_head events;
+	struct swait_head wq;
+
+	raw_spinlock_t lock;
+
+	struct task_struct *task;
+	int refs;
+};
+
+static bool swork_readable(struct sworker *worker)
+{
+	bool r;
+
+	if (kthread_should_stop())
+		return true;
+
+	raw_spin_lock_irq(&worker->lock);
+	r = !list_empty(&worker->events);
+	raw_spin_unlock_irq(&worker->lock);
+
+	return r;
+}
+
+static int swork_kthread(void *arg)
+{
+	struct sworker *worker = arg;
+
+	for (;;) {
+		swait_event_interruptible(worker->wq,
+					swork_readable(worker));
+		if (kthread_should_stop())
+			break;
+
+		raw_spin_lock_irq(&worker->lock);
+		while (!list_empty(&worker->events)) {
+			struct swork_event *sev;
+
+			sev = list_first_entry(&worker->events,
+					struct swork_event, item);
+			list_del(&sev->item);
+			raw_spin_unlock_irq(&worker->lock);
+
+			WARN_ON_ONCE(!test_and_clear_bit(SWORK_EVENT_PENDING,
+							 &sev->flags));
+			sev->func(sev);
+			raw_spin_lock_irq(&worker->lock);
+		}
+		raw_spin_unlock_irq(&worker->lock);
+	}
+	return 0;
+}
+
+static struct sworker *swork_create(void)
+{
+	struct sworker *worker;
+
+	worker = kzalloc(sizeof(*worker), GFP_KERNEL);
+	if (!worker)
+		return ERR_PTR(-ENOMEM);
+
+	INIT_LIST_HEAD(&worker->events);
+	raw_spin_lock_init(&worker->lock);
+	init_swait_head(&worker->wq);
+
+	worker->task = kthread_run(swork_kthread, worker, "kswork");
+	if (IS_ERR(worker->task)) {
+		kfree(worker);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	return worker;
+}
+
+static void swork_destroy(struct sworker *worker)
+{
+	kthread_stop(worker->task);
+
+	WARN_ON(!list_empty(&worker->events));
+	kfree(worker);
+}
+
+/**
+ * swork_queue - queue swork
+ *
+ * Returns %false if @work was already on a queue, %true otherwise.
+ *
+ * The work is queued and processed on a random CPU
+ */
+bool swork_queue(struct swork_event *sev)
+{
+	unsigned long flags;
+
+	if (test_and_set_bit(SWORK_EVENT_PENDING, &sev->flags))
+		return false;
+
+	raw_spin_lock_irqsave(&glob_worker->lock, flags);
+	list_add_tail(&sev->item, &glob_worker->events);
+	raw_spin_unlock_irqrestore(&glob_worker->lock, flags);
+
+	swait_wake(&glob_worker->wq);
+	return true;
+}
+EXPORT_SYMBOL_GPL(swork_queue);
+
+/**
+ * swork_get - get an instance of the sworker
+ *
+ * Returns an negative error code if the initialization if the worker did not
+ * work, %0 otherwise.
+ *
+ */
+int swork_get(void)
+{
+	struct sworker *worker;
+
+	mutex_lock(&worker_mutex);
+	if (!glob_worker) {
+		worker = swork_create();
+		if (IS_ERR(worker)) {
+			mutex_unlock(&worker_mutex);
+			return -ENOMEM;
+		}
+
+		glob_worker = worker;
+	}
+
+	glob_worker->refs++;
+	mutex_unlock(&worker_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(swork_get);
+
+/**
+ * swork_put - puts an instance of the sworker
+ *
+ * Will destroy the sworker thread. This function must not be called until all
+ * queued events have been completed.
+ */
+void swork_put(void)
+{
+	mutex_lock(&worker_mutex);
+
+	glob_worker->refs--;
+	if (glob_worker->refs > 0)
+		goto out;
+
+	swork_destroy(glob_worker);
+	glob_worker = NULL;
+out:
+	mutex_unlock(&worker_mutex);
+}
+EXPORT_SYMBOL_GPL(swork_put);
diff -Nur linux-3.18.12.orig/kernel/signal.c linux-3.18.12/kernel/signal.c
--- linux-3.18.12.orig/kernel/signal.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/signal.c	2015-04-26 13:32:22.447684003 -0500
@@ -14,6 +14,7 @@
 #include <linux/export.h>
 #include <linux/init.h>
 #include <linux/sched.h>
+#include <linux/sched/rt.h>
 #include <linux/fs.h>
 #include <linux/tty.h>
 #include <linux/binfmts.h>
@@ -352,13 +353,45 @@
 	return false;
 }
 
+#ifdef __HAVE_ARCH_CMPXCHG
+static inline struct sigqueue *get_task_cache(struct task_struct *t)
+{
+	struct sigqueue *q = t->sigqueue_cache;
+
+	if (cmpxchg(&t->sigqueue_cache, q, NULL) != q)
+		return NULL;
+	return q;
+}
+
+static inline int put_task_cache(struct task_struct *t, struct sigqueue *q)
+{
+	if (cmpxchg(&t->sigqueue_cache, NULL, q) == NULL)
+		return 0;
+	return 1;
+}
+
+#else
+
+static inline struct sigqueue *get_task_cache(struct task_struct *t)
+{
+	return NULL;
+}
+
+static inline int put_task_cache(struct task_struct *t, struct sigqueue *q)
+{
+	return 1;
+}
+
+#endif
+
 /*
  * allocate a new signal queue record
  * - this may be called without locks if and only if t == current, otherwise an
  *   appropriate lock must be held to stop the target task from exiting
  */
 static struct sigqueue *
-__sigqueue_alloc(int sig, struct task_struct *t, gfp_t flags, int override_rlimit)
+__sigqueue_do_alloc(int sig, struct task_struct *t, gfp_t flags,
+		    int override_rlimit, int fromslab)
 {
 	struct sigqueue *q = NULL;
 	struct user_struct *user;
@@ -375,7 +408,10 @@
 	if (override_rlimit ||
 	    atomic_read(&user->sigpending) <=
 			task_rlimit(t, RLIMIT_SIGPENDING)) {
-		q = kmem_cache_alloc(sigqueue_cachep, flags);
+		if (!fromslab)
+			q = get_task_cache(t);
+		if (!q)
+			q = kmem_cache_alloc(sigqueue_cachep, flags);
 	} else {
 		print_dropped_signal(sig);
 	}
@@ -392,6 +428,13 @@
 	return q;
 }
 
+static struct sigqueue *
+__sigqueue_alloc(int sig, struct task_struct *t, gfp_t flags,
+		 int override_rlimit)
+{
+	return __sigqueue_do_alloc(sig, t, flags, override_rlimit, 0);
+}
+
 static void __sigqueue_free(struct sigqueue *q)
 {
 	if (q->flags & SIGQUEUE_PREALLOC)
@@ -401,6 +444,21 @@
 	kmem_cache_free(sigqueue_cachep, q);
 }
 
+static void sigqueue_free_current(struct sigqueue *q)
+{
+	struct user_struct *up;
+
+	if (q->flags & SIGQUEUE_PREALLOC)
+		return;
+
+	up = q->user;
+	if (rt_prio(current->normal_prio) && !put_task_cache(current, q)) {
+		atomic_dec(&up->sigpending);
+		free_uid(up);
+	} else
+		  __sigqueue_free(q);
+}
+
 void flush_sigqueue(struct sigpending *queue)
 {
 	struct sigqueue *q;
@@ -414,6 +472,21 @@
 }
 
 /*
+ * Called from __exit_signal. Flush tsk->pending and
+ * tsk->sigqueue_cache
+ */
+void flush_task_sigqueue(struct task_struct *tsk)
+{
+	struct sigqueue *q;
+
+	flush_sigqueue(&tsk->pending);
+
+	q = get_task_cache(tsk);
+	if (q)
+		kmem_cache_free(sigqueue_cachep, q);
+}
+
+/*
  * Flush all pending signals for a task.
  */
 void __flush_signals(struct task_struct *t)
@@ -565,7 +638,7 @@
 still_pending:
 		list_del_init(&first->list);
 		copy_siginfo(info, &first->info);
-		__sigqueue_free(first);
+		sigqueue_free_current(first);
 	} else {
 		/*
 		 * Ok, it wasn't in the queue.  This must be
@@ -611,6 +684,8 @@
 {
 	int signr;
 
+	WARN_ON_ONCE(tsk != current);
+
 	/* We only dequeue private signals from ourselves, we don't let
 	 * signalfd steal them
 	 */
@@ -1207,8 +1282,8 @@
  * We don't want to have recursive SIGSEGV's etc, for example,
  * that is why we also clear SIGNAL_UNKILLABLE.
  */
-int
-force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
+static int
+do_force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
 {
 	unsigned long int flags;
 	int ret, blocked, ignored;
@@ -1233,6 +1308,39 @@
 	return ret;
 }
 
+int force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
+{
+/*
+ * On some archs, PREEMPT_RT has to delay sending a signal from a trap
+ * since it can not enable preemption, and the signal code's spin_locks
+ * turn into mutexes. Instead, it must set TIF_NOTIFY_RESUME which will
+ * send the signal on exit of the trap.
+ */
+#ifdef ARCH_RT_DELAYS_SIGNAL_SEND
+	if (in_atomic()) {
+		if (WARN_ON_ONCE(t != current))
+			return 0;
+		if (WARN_ON_ONCE(t->forced_info.si_signo))
+			return 0;
+
+		if (is_si_special(info)) {
+			WARN_ON_ONCE(info != SEND_SIG_PRIV);
+			t->forced_info.si_signo = sig;
+			t->forced_info.si_errno = 0;
+			t->forced_info.si_code = SI_KERNEL;
+			t->forced_info.si_pid = 0;
+			t->forced_info.si_uid = 0;
+		} else {
+			t->forced_info = *info;
+		}
+
+		set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
+		return 0;
+	}
+#endif
+	return do_force_sig_info(sig, info, t);
+}
+
 /*
  * Nuke all other threads in the group.
  */
@@ -1267,12 +1375,12 @@
 		 * Disable interrupts early to avoid deadlocks.
 		 * See rcu_read_unlock() comment header for details.
 		 */
-		local_irq_save(*flags);
+		local_irq_save_nort(*flags);
 		rcu_read_lock();
 		sighand = rcu_dereference(tsk->sighand);
 		if (unlikely(sighand == NULL)) {
 			rcu_read_unlock();
-			local_irq_restore(*flags);
+			local_irq_restore_nort(*flags);
 			break;
 		}
 
@@ -1283,7 +1391,7 @@
 		}
 		spin_unlock(&sighand->siglock);
 		rcu_read_unlock();
-		local_irq_restore(*flags);
+		local_irq_restore_nort(*flags);
 	}
 
 	return sighand;
@@ -1528,7 +1636,8 @@
  */
 struct sigqueue *sigqueue_alloc(void)
 {
-	struct sigqueue *q = __sigqueue_alloc(-1, current, GFP_KERNEL, 0);
+	/* Preallocated sigqueue objects always from the slabcache ! */
+	struct sigqueue *q = __sigqueue_do_alloc(-1, current, GFP_KERNEL, 0, 1);
 
 	if (q)
 		q->flags |= SIGQUEUE_PREALLOC;
@@ -1889,15 +1998,7 @@
 		if (gstop_done && ptrace_reparented(current))
 			do_notify_parent_cldstop(current, false, why);
 
-		/*
-		 * Don't want to allow preemption here, because
-		 * sys_ptrace() needs this task to be inactive.
-		 *
-		 * XXX: implement read_unlock_no_resched().
-		 */
-		preempt_disable();
 		read_unlock(&tasklist_lock);
-		preempt_enable_no_resched();
 		freezable_schedule();
 	} else {
 		/*
diff -Nur linux-3.18.12.orig/kernel/softirq.c linux-3.18.12/kernel/softirq.c
--- linux-3.18.12.orig/kernel/softirq.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/softirq.c	2015-04-26 13:32:22.451684003 -0500
@@ -21,10 +21,12 @@
 #include <linux/freezer.h>
 #include <linux/kthread.h>
 #include <linux/rcupdate.h>
+#include <linux/delay.h>
 #include <linux/ftrace.h>
 #include <linux/smp.h>
 #include <linux/smpboot.h>
 #include <linux/tick.h>
+#include <linux/locallock.h>
 #include <linux/irq.h>
 
 #define CREATE_TRACE_POINTS
@@ -62,6 +64,98 @@
 	"TASKLET", "SCHED", "HRTIMER", "RCU"
 };
 
+#ifdef CONFIG_NO_HZ_COMMON
+# ifdef CONFIG_PREEMPT_RT_FULL
+
+struct softirq_runner {
+	struct task_struct *runner[NR_SOFTIRQS];
+};
+
+static DEFINE_PER_CPU(struct softirq_runner, softirq_runners);
+
+static inline void softirq_set_runner(unsigned int sirq)
+{
+	struct softirq_runner *sr = &__get_cpu_var(softirq_runners);
+
+	sr->runner[sirq] = current;
+}
+
+static inline void softirq_clr_runner(unsigned int sirq)
+{
+	struct softirq_runner *sr = &__get_cpu_var(softirq_runners);
+
+	sr->runner[sirq] = NULL;
+}
+
+/*
+ * On preempt-rt a softirq running context might be blocked on a
+ * lock. There might be no other runnable task on this CPU because the
+ * lock owner runs on some other CPU. So we have to go into idle with
+ * the pending bit set. Therefor we need to check this otherwise we
+ * warn about false positives which confuses users and defeats the
+ * whole purpose of this test.
+ *
+ * This code is called with interrupts disabled.
+ */
+void softirq_check_pending_idle(void)
+{
+	static int rate_limit;
+	struct softirq_runner *sr = &__get_cpu_var(softirq_runners);
+	u32 warnpending;
+	int i;
+
+	if (rate_limit >= 10)
+		return;
+
+	warnpending = local_softirq_pending() & SOFTIRQ_STOP_IDLE_MASK;
+	for (i = 0; i < NR_SOFTIRQS; i++) {
+		struct task_struct *tsk = sr->runner[i];
+
+		/*
+		 * The wakeup code in rtmutex.c wakes up the task
+		 * _before_ it sets pi_blocked_on to NULL under
+		 * tsk->pi_lock. So we need to check for both: state
+		 * and pi_blocked_on.
+		 */
+		if (tsk) {
+			raw_spin_lock(&tsk->pi_lock);
+			if (tsk->pi_blocked_on || tsk->state == TASK_RUNNING) {
+				/* Clear all bits pending in that task */
+				warnpending &= ~(tsk->softirqs_raised);
+				warnpending &= ~(1 << i);
+			}
+			raw_spin_unlock(&tsk->pi_lock);
+		}
+	}
+
+	if (warnpending) {
+		printk(KERN_ERR "NOHZ: local_softirq_pending %02x\n",
+		       warnpending);
+		rate_limit++;
+	}
+}
+# else
+/*
+ * On !PREEMPT_RT we just printk rate limited:
+ */
+void softirq_check_pending_idle(void)
+{
+	static int rate_limit;
+
+	if (rate_limit < 10 &&
+			(local_softirq_pending() & SOFTIRQ_STOP_IDLE_MASK)) {
+		printk(KERN_ERR "NOHZ: local_softirq_pending %02x\n",
+		       local_softirq_pending());
+		rate_limit++;
+	}
+}
+# endif
+
+#else /* !CONFIG_NO_HZ_COMMON */
+static inline void softirq_set_runner(unsigned int sirq) { }
+static inline void softirq_clr_runner(unsigned int sirq) { }
+#endif
+
 /*
  * we cannot loop indefinitely here to avoid userspace starvation,
  * but we also don't want to introduce a worst case 1/HZ latency
@@ -77,6 +171,70 @@
 		wake_up_process(tsk);
 }
 
+static void handle_softirq(unsigned int vec_nr)
+{
+	struct softirq_action *h = softirq_vec + vec_nr;
+	int prev_count;
+
+	prev_count = preempt_count();
+
+	kstat_incr_softirqs_this_cpu(vec_nr);
+
+	trace_softirq_entry(vec_nr);
+	h->action(h);
+	trace_softirq_exit(vec_nr);
+	if (unlikely(prev_count != preempt_count())) {
+		pr_err("huh, entered softirq %u %s %p with preempt_count %08x, exited with %08x?\n",
+		       vec_nr, softirq_to_name[vec_nr], h->action,
+		       prev_count, preempt_count());
+		preempt_count_set(prev_count);
+	}
+}
+
+#ifndef CONFIG_PREEMPT_RT_FULL
+static inline int ksoftirqd_softirq_pending(void)
+{
+	return local_softirq_pending();
+}
+
+static void handle_pending_softirqs(u32 pending, int need_rcu_bh_qs)
+{
+	struct softirq_action *h = softirq_vec;
+	int softirq_bit;
+
+	local_irq_enable();
+
+	h = softirq_vec;
+
+	while ((softirq_bit = ffs(pending))) {
+		unsigned int vec_nr;
+
+		h += softirq_bit - 1;
+		vec_nr = h - softirq_vec;
+		handle_softirq(vec_nr);
+
+		h++;
+		pending >>= softirq_bit;
+	}
+
+	if (need_rcu_bh_qs)
+		rcu_bh_qs();
+	local_irq_disable();
+}
+
+static void run_ksoftirqd(unsigned int cpu)
+{
+	local_irq_disable();
+	if (ksoftirqd_softirq_pending()) {
+		__do_softirq();
+		rcu_note_context_switch(cpu);
+		local_irq_enable();
+		cond_resched();
+		return;
+	}
+	local_irq_enable();
+}
+
 /*
  * preempt_count and SOFTIRQ_OFFSET usage:
  * - preempt_count is changed by SOFTIRQ_OFFSET on entering or leaving
@@ -228,10 +386,8 @@
 	unsigned long end = jiffies + MAX_SOFTIRQ_TIME;
 	unsigned long old_flags = current->flags;
 	int max_restart = MAX_SOFTIRQ_RESTART;
-	struct softirq_action *h;
 	bool in_hardirq;
 	__u32 pending;
-	int softirq_bit;
 
 	/*
 	 * Mask out PF_MEMALLOC s current task context is borrowed for the
@@ -250,36 +406,7 @@
 	/* Reset the pending bitmask before enabling irqs */
 	set_softirq_pending(0);
 
-	local_irq_enable();
-
-	h = softirq_vec;
-
-	while ((softirq_bit = ffs(pending))) {
-		unsigned int vec_nr;
-		int prev_count;
-
-		h += softirq_bit - 1;
-
-		vec_nr = h - softirq_vec;
-		prev_count = preempt_count();
-
-		kstat_incr_softirqs_this_cpu(vec_nr);
-
-		trace_softirq_entry(vec_nr);
-		h->action(h);
-		trace_softirq_exit(vec_nr);
-		if (unlikely(prev_count != preempt_count())) {
-			pr_err("huh, entered softirq %u %s %p with preempt_count %08x, exited with %08x?\n",
-			       vec_nr, softirq_to_name[vec_nr], h->action,
-			       prev_count, preempt_count());
-			preempt_count_set(prev_count);
-		}
-		h++;
-		pending >>= softirq_bit;
-	}
-
-	rcu_bh_qs();
-	local_irq_disable();
+	handle_pending_softirqs(pending, 1);
 
 	pending = local_softirq_pending();
 	if (pending) {
@@ -316,6 +443,285 @@
 }
 
 /*
+ * This function must run with irqs disabled!
+ */
+void raise_softirq_irqoff(unsigned int nr)
+{
+	__raise_softirq_irqoff(nr);
+
+	/*
+	 * If we're in an interrupt or softirq, we're done
+	 * (this also catches softirq-disabled code). We will
+	 * actually run the softirq once we return from
+	 * the irq or softirq.
+	 *
+	 * Otherwise we wake up ksoftirqd to make sure we
+	 * schedule the softirq soon.
+	 */
+	if (!in_interrupt())
+		wakeup_softirqd();
+}
+
+void __raise_softirq_irqoff(unsigned int nr)
+{
+	trace_softirq_raise(nr);
+	or_softirq_pending(1UL << nr);
+}
+
+static inline void local_bh_disable_nort(void) { local_bh_disable(); }
+static inline void _local_bh_enable_nort(void) { _local_bh_enable(); }
+static void ksoftirqd_set_sched_params(unsigned int cpu) { }
+static void ksoftirqd_clr_sched_params(unsigned int cpu, bool online) { }
+
+#else /* !PREEMPT_RT_FULL */
+
+/*
+ * On RT we serialize softirq execution with a cpu local lock per softirq
+ */
+static DEFINE_PER_CPU(struct local_irq_lock [NR_SOFTIRQS], local_softirq_locks);
+
+void __init softirq_early_init(void)
+{
+	int i;
+
+	for (i = 0; i < NR_SOFTIRQS; i++)
+		local_irq_lock_init(local_softirq_locks[i]);
+}
+
+static void lock_softirq(int which)
+{
+	local_lock(local_softirq_locks[which]);
+}
+
+static void unlock_softirq(int which)
+{
+	local_unlock(local_softirq_locks[which]);
+}
+
+static void do_single_softirq(int which, int need_rcu_bh_qs)
+{
+	unsigned long old_flags = current->flags;
+
+	current->flags &= ~PF_MEMALLOC;
+	vtime_account_irq_enter(current);
+	current->flags |= PF_IN_SOFTIRQ;
+	lockdep_softirq_enter();
+	local_irq_enable();
+	handle_softirq(which);
+	local_irq_disable();
+	lockdep_softirq_exit();
+	current->flags &= ~PF_IN_SOFTIRQ;
+	vtime_account_irq_enter(current);
+	tsk_restore_flags(current, old_flags, PF_MEMALLOC);
+}
+
+/*
+ * Called with interrupts disabled. Process softirqs which were raised
+ * in current context (or on behalf of ksoftirqd).
+ */
+static void do_current_softirqs(int need_rcu_bh_qs)
+{
+	while (current->softirqs_raised) {
+		int i = __ffs(current->softirqs_raised);
+		unsigned int pending, mask = (1U << i);
+
+		current->softirqs_raised &= ~mask;
+		local_irq_enable();
+
+		/*
+		 * If the lock is contended, we boost the owner to
+		 * process the softirq or leave the critical section
+		 * now.
+		 */
+		lock_softirq(i);
+		local_irq_disable();
+		softirq_set_runner(i);
+		/*
+		 * Check with the local_softirq_pending() bits,
+		 * whether we need to process this still or if someone
+		 * else took care of it.
+		 */
+		pending = local_softirq_pending();
+		if (pending & mask) {
+			set_softirq_pending(pending & ~mask);
+			do_single_softirq(i, need_rcu_bh_qs);
+		}
+		softirq_clr_runner(i);
+		unlock_softirq(i);
+		WARN_ON(current->softirq_nestcnt != 1);
+	}
+}
+
+static void __local_bh_disable(void)
+{
+	if (++current->softirq_nestcnt == 1)
+		migrate_disable();
+}
+
+void local_bh_disable(void)
+{
+	__local_bh_disable();
+}
+EXPORT_SYMBOL(local_bh_disable);
+
+void __local_bh_disable_ip(unsigned long ip, unsigned int cnt)
+{
+	__local_bh_disable();
+	if (cnt & PREEMPT_CHECK_OFFSET)
+		preempt_disable();
+}
+
+static void __local_bh_enable(void)
+{
+	if (WARN_ON(current->softirq_nestcnt == 0))
+		return;
+
+	local_irq_disable();
+	if (current->softirq_nestcnt == 1 && current->softirqs_raised)
+		do_current_softirqs(1);
+	local_irq_enable();
+
+	if (--current->softirq_nestcnt == 0)
+		migrate_enable();
+}
+
+void local_bh_enable(void)
+{
+	__local_bh_enable();
+}
+EXPORT_SYMBOL(local_bh_enable);
+
+extern void __local_bh_enable_ip(unsigned long ip, unsigned int cnt)
+{
+	__local_bh_enable();
+	if (cnt & PREEMPT_CHECK_OFFSET)
+		preempt_enable();
+}
+
+void local_bh_enable_ip(unsigned long ip)
+{
+	local_bh_enable();
+}
+EXPORT_SYMBOL(local_bh_enable_ip);
+
+void _local_bh_enable(void)
+{
+	if (WARN_ON(current->softirq_nestcnt == 0))
+		return;
+	if (--current->softirq_nestcnt == 0)
+		migrate_enable();
+}
+EXPORT_SYMBOL(_local_bh_enable);
+
+int in_serving_softirq(void)
+{
+	return current->flags & PF_IN_SOFTIRQ;
+}
+EXPORT_SYMBOL(in_serving_softirq);
+
+/* Called with preemption disabled */
+static void run_ksoftirqd(unsigned int cpu)
+{
+	local_irq_disable();
+	current->softirq_nestcnt++;
+
+	do_current_softirqs(1);
+	current->softirq_nestcnt--;
+	rcu_note_context_switch(cpu);
+	local_irq_enable();
+}
+
+/*
+ * Called from netif_rx_ni(). Preemption enabled, but migration
+ * disabled. So the cpu can't go away under us.
+ */
+void thread_do_softirq(void)
+{
+	if (!in_serving_softirq() && current->softirqs_raised) {
+		current->softirq_nestcnt++;
+		do_current_softirqs(0);
+		current->softirq_nestcnt--;
+	}
+}
+
+static void do_raise_softirq_irqoff(unsigned int nr)
+{
+	trace_softirq_raise(nr);
+	or_softirq_pending(1UL << nr);
+
+	/*
+	 * If we are not in a hard interrupt and inside a bh disabled
+	 * region, we simply raise the flag on current. local_bh_enable()
+	 * will make sure that the softirq is executed. Otherwise we
+	 * delegate it to ksoftirqd.
+	 */
+	if (!in_irq() && current->softirq_nestcnt)
+		current->softirqs_raised |= (1U << nr);
+	else if (__this_cpu_read(ksoftirqd))
+		__this_cpu_read(ksoftirqd)->softirqs_raised |= (1U << nr);
+}
+
+void __raise_softirq_irqoff(unsigned int nr)
+{
+	do_raise_softirq_irqoff(nr);
+	if (!in_irq() && !current->softirq_nestcnt)
+		wakeup_softirqd();
+}
+
+/*
+ * This function must run with irqs disabled!
+ */
+void raise_softirq_irqoff(unsigned int nr)
+{
+	do_raise_softirq_irqoff(nr);
+
+	/*
+	 * If we're in an hard interrupt we let irq return code deal
+	 * with the wakeup of ksoftirqd.
+	 */
+	if (in_irq())
+		return;
+	/*
+	 * If we are in thread context but outside of a bh disabled
+	 * region, we need to wake ksoftirqd as well.
+	 *
+	 * CHECKME: Some of the places which do that could be wrapped
+	 * into local_bh_disable/enable pairs. Though it's unclear
+	 * whether this is worth the effort. To find those places just
+	 * raise a WARN() if the condition is met.
+	 */
+	if (!current->softirq_nestcnt)
+		wakeup_softirqd();
+}
+
+static inline int ksoftirqd_softirq_pending(void)
+{
+	return current->softirqs_raised;
+}
+
+static inline void local_bh_disable_nort(void) { }
+static inline void _local_bh_enable_nort(void) { }
+
+static inline void ksoftirqd_set_sched_params(unsigned int cpu)
+{
+	struct sched_param param = { .sched_priority = 1 };
+
+	sched_setscheduler(current, SCHED_FIFO, &param);
+	/* Take over all pending softirqs when starting */
+	local_irq_disable();
+	current->softirqs_raised = local_softirq_pending();
+	local_irq_enable();
+}
+
+static inline void ksoftirqd_clr_sched_params(unsigned int cpu, bool online)
+{
+	struct sched_param param = { .sched_priority = 0 };
+
+	sched_setscheduler(current, SCHED_NORMAL, &param);
+}
+
+#endif /* PREEMPT_RT_FULL */
+/*
  * Enter an interrupt context.
  */
 void irq_enter(void)
@@ -326,9 +732,9 @@
 		 * Prevent raise_softirq from needlessly waking up ksoftirqd
 		 * here, as softirq will be serviced on return from interrupt.
 		 */
-		local_bh_disable();
+		local_bh_disable_nort();
 		tick_irq_enter();
-		_local_bh_enable();
+		_local_bh_enable_nort();
 	}
 
 	__irq_enter();
@@ -336,6 +742,7 @@
 
 static inline void invoke_softirq(void)
 {
+#ifndef CONFIG_PREEMPT_RT_FULL
 	if (!force_irqthreads) {
 #ifdef CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK
 		/*
@@ -355,6 +762,15 @@
 	} else {
 		wakeup_softirqd();
 	}
+#else /* PREEMPT_RT_FULL */
+	unsigned long flags;
+
+	local_irq_save(flags);
+	if (__this_cpu_read(ksoftirqd) &&
+			__this_cpu_read(ksoftirqd)->softirqs_raised)
+		wakeup_softirqd();
+	local_irq_restore(flags);
+#endif
 }
 
 static inline void tick_irq_exit(void)
@@ -391,26 +807,6 @@
 	trace_hardirq_exit(); /* must be last! */
 }
 
-/*
- * This function must run with irqs disabled!
- */
-inline void raise_softirq_irqoff(unsigned int nr)
-{
-	__raise_softirq_irqoff(nr);
-
-	/*
-	 * If we're in an interrupt or softirq, we're done
-	 * (this also catches softirq-disabled code). We will
-	 * actually run the softirq once we return from
-	 * the irq or softirq.
-	 *
-	 * Otherwise we wake up ksoftirqd to make sure we
-	 * schedule the softirq soon.
-	 */
-	if (!in_interrupt())
-		wakeup_softirqd();
-}
-
 void raise_softirq(unsigned int nr)
 {
 	unsigned long flags;
@@ -420,12 +816,6 @@
 	local_irq_restore(flags);
 }
 
-void __raise_softirq_irqoff(unsigned int nr)
-{
-	trace_softirq_raise(nr);
-	or_softirq_pending(1UL << nr);
-}
-
 void open_softirq(int nr, void (*action)(struct softirq_action *))
 {
 	softirq_vec[nr].action = action;
@@ -442,15 +832,45 @@
 static DEFINE_PER_CPU(struct tasklet_head, tasklet_vec);
 static DEFINE_PER_CPU(struct tasklet_head, tasklet_hi_vec);
 
+static void inline
+__tasklet_common_schedule(struct tasklet_struct *t, struct tasklet_head *head, unsigned int nr)
+{
+	if (tasklet_trylock(t)) {
+again:
+		/* We may have been preempted before tasklet_trylock
+		 * and __tasklet_action may have already run.
+		 * So double check the sched bit while the takslet
+		 * is locked before adding it to the list.
+		 */
+		if (test_bit(TASKLET_STATE_SCHED, &t->state)) {
+			t->next = NULL;
+			*head->tail = t;
+			head->tail = &(t->next);
+			raise_softirq_irqoff(nr);
+			tasklet_unlock(t);
+		} else {
+			/* This is subtle. If we hit the corner case above
+			 * It is possible that we get preempted right here,
+			 * and another task has successfully called
+			 * tasklet_schedule(), then this function, and
+			 * failed on the trylock. Thus we must be sure
+			 * before releasing the tasklet lock, that the
+			 * SCHED_BIT is clear. Otherwise the tasklet
+			 * may get its SCHED_BIT set, but not added to the
+			 * list
+			 */
+			if (!tasklet_tryunlock(t))
+				goto again;
+		}
+	}
+}
+
 void __tasklet_schedule(struct tasklet_struct *t)
 {
 	unsigned long flags;
 
 	local_irq_save(flags);
-	t->next = NULL;
-	*__this_cpu_read(tasklet_vec.tail) = t;
-	__this_cpu_write(tasklet_vec.tail, &(t->next));
-	raise_softirq_irqoff(TASKLET_SOFTIRQ);
+	__tasklet_common_schedule(t, &__get_cpu_var(tasklet_vec), TASKLET_SOFTIRQ);
 	local_irq_restore(flags);
 }
 EXPORT_SYMBOL(__tasklet_schedule);
@@ -460,10 +880,7 @@
 	unsigned long flags;
 
 	local_irq_save(flags);
-	t->next = NULL;
-	*__this_cpu_read(tasklet_hi_vec.tail) = t;
-	__this_cpu_write(tasklet_hi_vec.tail,  &(t->next));
-	raise_softirq_irqoff(HI_SOFTIRQ);
+	__tasklet_common_schedule(t, &__get_cpu_var(tasklet_hi_vec), HI_SOFTIRQ);
 	local_irq_restore(flags);
 }
 EXPORT_SYMBOL(__tasklet_hi_schedule);
@@ -472,48 +889,116 @@
 {
 	BUG_ON(!irqs_disabled());
 
-	t->next = __this_cpu_read(tasklet_hi_vec.head);
-	__this_cpu_write(tasklet_hi_vec.head, t);
-	__raise_softirq_irqoff(HI_SOFTIRQ);
+	__tasklet_hi_schedule(t);
 }
 EXPORT_SYMBOL(__tasklet_hi_schedule_first);
 
-static void tasklet_action(struct softirq_action *a)
+void  tasklet_enable(struct tasklet_struct *t)
 {
-	struct tasklet_struct *list;
+	if (!atomic_dec_and_test(&t->count))
+		return;
+	if (test_and_clear_bit(TASKLET_STATE_PENDING, &t->state))
+		tasklet_schedule(t);
+}
+EXPORT_SYMBOL(tasklet_enable);
 
-	local_irq_disable();
-	list = __this_cpu_read(tasklet_vec.head);
-	__this_cpu_write(tasklet_vec.head, NULL);
-	__this_cpu_write(tasklet_vec.tail, this_cpu_ptr(&tasklet_vec.head));
-	local_irq_enable();
+void  tasklet_hi_enable(struct tasklet_struct *t)
+{
+	if (!atomic_dec_and_test(&t->count))
+		return;
+	if (test_and_clear_bit(TASKLET_STATE_PENDING, &t->state))
+		tasklet_hi_schedule(t);
+}
+EXPORT_SYMBOL(tasklet_hi_enable);
+
+static void __tasklet_action(struct softirq_action *a,
+			     struct tasklet_struct *list)
+{
+	int loops = 1000000;
 
 	while (list) {
 		struct tasklet_struct *t = list;
 
 		list = list->next;
 
-		if (tasklet_trylock(t)) {
-			if (!atomic_read(&t->count)) {
-				if (!test_and_clear_bit(TASKLET_STATE_SCHED,
-							&t->state))
-					BUG();
-				t->func(t->data);
-				tasklet_unlock(t);
-				continue;
-			}
-			tasklet_unlock(t);
+		/*
+		 * Should always succeed - after a tasklist got on the
+		 * list (after getting the SCHED bit set from 0 to 1),
+		 * nothing but the tasklet softirq it got queued to can
+		 * lock it:
+		 */
+		if (!tasklet_trylock(t)) {
+			WARN_ON(1);
+			continue;
 		}
 
-		local_irq_disable();
 		t->next = NULL;
-		*__this_cpu_read(tasklet_vec.tail) = t;
-		__this_cpu_write(tasklet_vec.tail, &(t->next));
-		__raise_softirq_irqoff(TASKLET_SOFTIRQ);
-		local_irq_enable();
+
+		/*
+		 * If we cannot handle the tasklet because it's disabled,
+		 * mark it as pending. tasklet_enable() will later
+		 * re-schedule the tasklet.
+		 */
+		if (unlikely(atomic_read(&t->count))) {
+out_disabled:
+			/* implicit unlock: */
+			wmb();
+			t->state = TASKLET_STATEF_PENDING;
+			continue;
+		}
+
+		/*
+		 * After this point on the tasklet might be rescheduled
+		 * on another CPU, but it can only be added to another
+		 * CPU's tasklet list if we unlock the tasklet (which we
+		 * dont do yet).
+		 */
+		if (!test_and_clear_bit(TASKLET_STATE_SCHED, &t->state))
+			WARN_ON(1);
+
+again:
+		t->func(t->data);
+
+		/*
+		 * Try to unlock the tasklet. We must use cmpxchg, because
+		 * another CPU might have scheduled or disabled the tasklet.
+		 * We only allow the STATE_RUN -> 0 transition here.
+		 */
+		while (!tasklet_tryunlock(t)) {
+			/*
+			 * If it got disabled meanwhile, bail out:
+			 */
+			if (atomic_read(&t->count))
+				goto out_disabled;
+			/*
+			 * If it got scheduled meanwhile, re-execute
+			 * the tasklet function:
+			 */
+			if (test_and_clear_bit(TASKLET_STATE_SCHED, &t->state))
+				goto again;
+			if (!--loops) {
+				printk("hm, tasklet state: %08lx\n", t->state);
+				WARN_ON(1);
+				tasklet_unlock(t);
+				break;
+			}
+		}
 	}
 }
 
+static void tasklet_action(struct softirq_action *a)
+{
+	struct tasklet_struct *list;
+
+	local_irq_disable();
+	list = __get_cpu_var(tasklet_vec).head;
+	__get_cpu_var(tasklet_vec).head = NULL;
+	__get_cpu_var(tasklet_vec).tail = &__get_cpu_var(tasklet_vec).head;
+	local_irq_enable();
+
+	__tasklet_action(a, list);
+}
+
 static void tasklet_hi_action(struct softirq_action *a)
 {
 	struct tasklet_struct *list;
@@ -524,30 +1009,7 @@
 	__this_cpu_write(tasklet_hi_vec.tail, this_cpu_ptr(&tasklet_hi_vec.head));
 	local_irq_enable();
 
-	while (list) {
-		struct tasklet_struct *t = list;
-
-		list = list->next;
-
-		if (tasklet_trylock(t)) {
-			if (!atomic_read(&t->count)) {
-				if (!test_and_clear_bit(TASKLET_STATE_SCHED,
-							&t->state))
-					BUG();
-				t->func(t->data);
-				tasklet_unlock(t);
-				continue;
-			}
-			tasklet_unlock(t);
-		}
-
-		local_irq_disable();
-		t->next = NULL;
-		*__this_cpu_read(tasklet_hi_vec.tail) = t;
-		__this_cpu_write(tasklet_hi_vec.tail, &(t->next));
-		__raise_softirq_irqoff(HI_SOFTIRQ);
-		local_irq_enable();
-	}
+	__tasklet_action(a, list);
 }
 
 void tasklet_init(struct tasklet_struct *t,
@@ -568,7 +1030,7 @@
 
 	while (test_and_set_bit(TASKLET_STATE_SCHED, &t->state)) {
 		do {
-			yield();
+			msleep(1);
 		} while (test_bit(TASKLET_STATE_SCHED, &t->state));
 	}
 	tasklet_unlock_wait(t);
@@ -642,26 +1104,26 @@
 	open_softirq(HI_SOFTIRQ, tasklet_hi_action);
 }
 
-static int ksoftirqd_should_run(unsigned int cpu)
-{
-	return local_softirq_pending();
-}
-
-static void run_ksoftirqd(unsigned int cpu)
+#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT_FULL)
+void tasklet_unlock_wait(struct tasklet_struct *t)
 {
-	local_irq_disable();
-	if (local_softirq_pending()) {
+	while (test_bit(TASKLET_STATE_RUN, &(t)->state)) {
 		/*
-		 * We can safely run softirq on inline stack, as we are not deep
-		 * in the task stack here.
+		 * Hack for now to avoid this busy-loop:
 		 */
-		__do_softirq();
-		rcu_note_context_switch(cpu);
-		local_irq_enable();
-		cond_resched();
-		return;
+#ifdef CONFIG_PREEMPT_RT_FULL
+		msleep(1);
+#else
+		barrier();
+#endif
 	}
-	local_irq_enable();
+}
+EXPORT_SYMBOL(tasklet_unlock_wait);
+#endif
+
+static int ksoftirqd_should_run(unsigned int cpu)
+{
+	return ksoftirqd_softirq_pending();
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -743,6 +1205,8 @@
 
 static struct smp_hotplug_thread softirq_threads = {
 	.store			= &ksoftirqd,
+	.setup			= ksoftirqd_set_sched_params,
+	.cleanup		= ksoftirqd_clr_sched_params,
 	.thread_should_run	= ksoftirqd_should_run,
 	.thread_fn		= run_ksoftirqd,
 	.thread_comm		= "ksoftirqd/%u",
diff -Nur linux-3.18.12.orig/kernel/stop_machine.c linux-3.18.12/kernel/stop_machine.c
--- linux-3.18.12.orig/kernel/stop_machine.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/stop_machine.c	2015-04-26 13:32:22.451684003 -0500
@@ -30,12 +30,12 @@
 	atomic_t		nr_todo;	/* nr left to execute */
 	bool			executed;	/* actually executed? */
 	int			ret;		/* collected return value */
-	struct completion	completion;	/* fired if nr_todo reaches 0 */
+	struct task_struct	*waiter;	/* woken when nr_todo reaches 0 */
 };
 
 /* the actual stopper, one per every possible cpu, enabled on online cpus */
 struct cpu_stopper {
-	spinlock_t		lock;
+	raw_spinlock_t		lock;
 	bool			enabled;	/* is this stopper enabled? */
 	struct list_head	works;		/* list of pending works */
 };
@@ -56,7 +56,7 @@
 {
 	memset(done, 0, sizeof(*done));
 	atomic_set(&done->nr_todo, nr_todo);
-	init_completion(&done->completion);
+	done->waiter = current;
 }
 
 /* signal completion unless @done is NULL */
@@ -65,8 +65,10 @@
 	if (done) {
 		if (executed)
 			done->executed = true;
-		if (atomic_dec_and_test(&done->nr_todo))
-			complete(&done->completion);
+		if (atomic_dec_and_test(&done->nr_todo)) {
+			wake_up_process(done->waiter);
+			done->waiter = NULL;
+		}
 	}
 }
 
@@ -78,7 +80,7 @@
 
 	unsigned long flags;
 
-	spin_lock_irqsave(&stopper->lock, flags);
+	raw_spin_lock_irqsave(&stopper->lock, flags);
 
 	if (stopper->enabled) {
 		list_add_tail(&work->list, &stopper->works);
@@ -86,7 +88,23 @@
 	} else
 		cpu_stop_signal_done(work->done, false);
 
-	spin_unlock_irqrestore(&stopper->lock, flags);
+	raw_spin_unlock_irqrestore(&stopper->lock, flags);
+}
+
+static void wait_for_stop_done(struct cpu_stop_done *done)
+{
+	set_current_state(TASK_UNINTERRUPTIBLE);
+	while (atomic_read(&done->nr_todo)) {
+		schedule();
+		set_current_state(TASK_UNINTERRUPTIBLE);
+	}
+	/*
+	 * We need to wait until cpu_stop_signal_done() has cleared
+	 * done->waiter.
+	 */
+	while (done->waiter)
+		cpu_relax();
+	set_current_state(TASK_RUNNING);
 }
 
 /**
@@ -120,7 +138,7 @@
 
 	cpu_stop_init_done(&done, 1);
 	cpu_stop_queue_work(cpu, &work);
-	wait_for_completion(&done.completion);
+	wait_for_stop_done(&done);
 	return done.executed ? done.ret : -ENOENT;
 }
 
@@ -248,7 +266,7 @@
 	struct irq_cpu_stop_queue_work_info call_args;
 	struct multi_stop_data msdata;
 
-	preempt_disable();
+	preempt_disable_nort();
 	msdata = (struct multi_stop_data){
 		.fn = fn,
 		.data = arg,
@@ -281,7 +299,7 @@
 	 * This relies on the stopper workqueues to be FIFO.
 	 */
 	if (!cpu_active(cpu1) || !cpu_active(cpu2)) {
-		preempt_enable();
+		preempt_enable_nort();
 		return -ENOENT;
 	}
 
@@ -295,9 +313,9 @@
 				 &irq_cpu_stop_queue_work,
 				 &call_args, 1);
 	lg_local_unlock(&stop_cpus_lock);
-	preempt_enable();
+	preempt_enable_nort();
 
-	wait_for_completion(&done.completion);
+	wait_for_stop_done(&done);
 
 	return done.executed ? done.ret : -ENOENT;
 }
@@ -329,7 +347,7 @@
 
 static void queue_stop_cpus_work(const struct cpumask *cpumask,
 				 cpu_stop_fn_t fn, void *arg,
-				 struct cpu_stop_done *done)
+				 struct cpu_stop_done *done, bool inactive)
 {
 	struct cpu_stop_work *work;
 	unsigned int cpu;
@@ -343,11 +361,13 @@
 	}
 
 	/*
-	 * Disable preemption while queueing to avoid getting
-	 * preempted by a stopper which might wait for other stoppers
-	 * to enter @fn which can lead to deadlock.
+	 * Make sure that all work is queued on all cpus before
+	 * any of the cpus can execute it.
 	 */
-	lg_global_lock(&stop_cpus_lock);
+	if (!inactive)
+		lg_global_lock(&stop_cpus_lock);
+	else
+		lg_global_trylock_relax(&stop_cpus_lock);
 	for_each_cpu(cpu, cpumask)
 		cpu_stop_queue_work(cpu, &per_cpu(stop_cpus_work, cpu));
 	lg_global_unlock(&stop_cpus_lock);
@@ -359,8 +379,8 @@
 	struct cpu_stop_done done;
 
 	cpu_stop_init_done(&done, cpumask_weight(cpumask));
-	queue_stop_cpus_work(cpumask, fn, arg, &done);
-	wait_for_completion(&done.completion);
+	queue_stop_cpus_work(cpumask, fn, arg, &done, false);
+	wait_for_stop_done(&done);
 	return done.executed ? done.ret : -ENOENT;
 }
 
@@ -439,9 +459,9 @@
 	unsigned long flags;
 	int run;
 
-	spin_lock_irqsave(&stopper->lock, flags);
+	raw_spin_lock_irqsave(&stopper->lock, flags);
 	run = !list_empty(&stopper->works);
-	spin_unlock_irqrestore(&stopper->lock, flags);
+	raw_spin_unlock_irqrestore(&stopper->lock, flags);
 	return run;
 }
 
@@ -453,13 +473,13 @@
 
 repeat:
 	work = NULL;
-	spin_lock_irq(&stopper->lock);
+	raw_spin_lock_irq(&stopper->lock);
 	if (!list_empty(&stopper->works)) {
 		work = list_first_entry(&stopper->works,
 					struct cpu_stop_work, list);
 		list_del_init(&work->list);
 	}
-	spin_unlock_irq(&stopper->lock);
+	raw_spin_unlock_irq(&stopper->lock);
 
 	if (work) {
 		cpu_stop_fn_t fn = work->fn;
@@ -467,6 +487,16 @@
 		struct cpu_stop_done *done = work->done;
 		char ksym_buf[KSYM_NAME_LEN] __maybe_unused;
 
+		/*
+		 * Wait until the stopper finished scheduling on all
+		 * cpus
+		 */
+		lg_global_lock(&stop_cpus_lock);
+		/*
+		 * Let other cpu threads continue as well
+		 */
+		lg_global_unlock(&stop_cpus_lock);
+
 		/* cpu stop callbacks are not allowed to sleep */
 		preempt_disable();
 
@@ -481,7 +511,13 @@
 			  kallsyms_lookup((unsigned long)fn, NULL, NULL, NULL,
 					  ksym_buf), arg);
 
+		/*
+		 * Make sure that the wakeup and setting done->waiter
+		 * to NULL is atomic.
+		 */
+		local_irq_disable();
 		cpu_stop_signal_done(done, true);
+		local_irq_enable();
 		goto repeat;
 	}
 }
@@ -500,20 +536,20 @@
 	unsigned long flags;
 
 	/* drain remaining works */
-	spin_lock_irqsave(&stopper->lock, flags);
+	raw_spin_lock_irqsave(&stopper->lock, flags);
 	list_for_each_entry(work, &stopper->works, list)
 		cpu_stop_signal_done(work->done, false);
 	stopper->enabled = false;
-	spin_unlock_irqrestore(&stopper->lock, flags);
+	raw_spin_unlock_irqrestore(&stopper->lock, flags);
 }
 
 static void cpu_stop_unpark(unsigned int cpu)
 {
 	struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
 
-	spin_lock_irq(&stopper->lock);
+	raw_spin_lock_irq(&stopper->lock);
 	stopper->enabled = true;
-	spin_unlock_irq(&stopper->lock);
+	raw_spin_unlock_irq(&stopper->lock);
 }
 
 static struct smp_hotplug_thread cpu_stop_threads = {
@@ -535,10 +571,12 @@
 	for_each_possible_cpu(cpu) {
 		struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
 
-		spin_lock_init(&stopper->lock);
+		raw_spin_lock_init(&stopper->lock);
 		INIT_LIST_HEAD(&stopper->works);
 	}
 
+	lg_lock_init(&stop_cpus_lock, "stop_cpus_lock");
+
 	BUG_ON(smpboot_register_percpu_thread(&cpu_stop_threads));
 	stop_machine_initialized = true;
 	return 0;
@@ -634,11 +672,11 @@
 	set_state(&msdata, MULTI_STOP_PREPARE);
 	cpu_stop_init_done(&done, num_active_cpus());
 	queue_stop_cpus_work(cpu_active_mask, multi_cpu_stop, &msdata,
-			     &done);
+			     &done, true);
 	ret = multi_cpu_stop(&msdata);
 
 	/* Busy wait for completion. */
-	while (!completion_done(&done.completion))
+	while (atomic_read(&done.nr_todo))
 		cpu_relax();
 
 	mutex_unlock(&stop_cpus_mutex);
diff -Nur linux-3.18.12.orig/kernel/time/hrtimer.c linux-3.18.12/kernel/time/hrtimer.c
--- linux-3.18.12.orig/kernel/time/hrtimer.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/time/hrtimer.c	2015-04-26 13:32:22.451684003 -0500
@@ -48,11 +48,13 @@
 #include <linux/sched/rt.h>
 #include <linux/sched/deadline.h>
 #include <linux/timer.h>
+#include <linux/kthread.h>
 #include <linux/freezer.h>
 
 #include <asm/uaccess.h>
 
 #include <trace/events/timer.h>
+#include <trace/events/hist.h>
 
 #include "timekeeping.h"
 
@@ -568,8 +570,7 @@
 	 * When the callback is running, we do not reprogram the clock event
 	 * device. The timer callback is either running on a different CPU or
 	 * the callback is executed in the hrtimer_interrupt context. The
-	 * reprogramming is handled either by the softirq, which called the
-	 * callback or at the end of the hrtimer_interrupt.
+	 * reprogramming is handled at the end of the hrtimer_interrupt.
 	 */
 	if (hrtimer_callback_running(timer))
 		return 0;
@@ -604,6 +605,9 @@
 	return res;
 }
 
+static void __run_hrtimer(struct hrtimer *timer, ktime_t *now);
+static int hrtimer_rt_defer(struct hrtimer *timer);
+
 /*
  * Initialize the high resolution related parts of cpu_base
  */
@@ -613,6 +617,21 @@
 	base->hres_active = 0;
 }
 
+static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
+					    struct hrtimer_clock_base *base,
+					    int wakeup)
+{
+	if (!hrtimer_reprogram(timer, base))
+		return 0;
+	if (!wakeup)
+		return -ETIME;
+#ifdef CONFIG_PREEMPT_RT_BASE
+	if (!hrtimer_rt_defer(timer))
+		return -ETIME;
+#endif
+	return 1;
+}
+
 static inline ktime_t hrtimer_update_base(struct hrtimer_cpu_base *base)
 {
 	ktime_t *offs_real = &base->clock_base[HRTIMER_BASE_REALTIME].offset;
@@ -678,6 +697,44 @@
 
 static DECLARE_WORK(hrtimer_work, clock_was_set_work);
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * RT can not call schedule_work from real interrupt context.
+ * Need to make a thread to do the real work.
+ */
+static struct task_struct *clock_set_delay_thread;
+static bool do_clock_set_delay;
+
+static int run_clock_set_delay(void *ignore)
+{
+	while (!kthread_should_stop()) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		if (do_clock_set_delay) {
+			do_clock_set_delay = false;
+			schedule_work(&hrtimer_work);
+		}
+		schedule();
+	}
+	__set_current_state(TASK_RUNNING);
+	return 0;
+}
+
+void clock_was_set_delayed(void)
+{
+	do_clock_set_delay = true;
+	/* Make visible before waking up process */
+	smp_wmb();
+	wake_up_process(clock_set_delay_thread);
+}
+
+static __init int create_clock_set_delay_thread(void)
+{
+	clock_set_delay_thread = kthread_run(run_clock_set_delay, NULL, "kclksetdelayd");
+	BUG_ON(!clock_set_delay_thread);
+	return 0;
+}
+early_initcall(create_clock_set_delay_thread);
+#else /* PREEMPT_RT_FULL */
 /*
  * Called from timekeeping and resume code to reprogramm the hrtimer
  * interrupt device on all cpus.
@@ -686,6 +743,7 @@
 {
 	schedule_work(&hrtimer_work);
 }
+#endif
 
 #else
 
@@ -694,6 +752,13 @@
 static inline int hrtimer_switch_to_hres(void) { return 0; }
 static inline void
 hrtimer_force_reprogram(struct hrtimer_cpu_base *base, int skip_equal) { }
+static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
+					    struct hrtimer_clock_base *base,
+					    int wakeup)
+{
+	return 0;
+}
+
 static inline int hrtimer_reprogram(struct hrtimer *timer,
 				    struct hrtimer_clock_base *base)
 {
@@ -701,7 +766,6 @@
 }
 static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) { }
 static inline void retrigger_next_event(void *arg) { }
-
 #endif /* CONFIG_HIGH_RES_TIMERS */
 
 /*
@@ -819,6 +883,32 @@
 }
 EXPORT_SYMBOL_GPL(hrtimer_forward);
 
+#ifdef CONFIG_PREEMPT_RT_BASE
+# define wake_up_timer_waiters(b)	wake_up(&(b)->wait)
+
+/**
+ * hrtimer_wait_for_timer - Wait for a running timer
+ *
+ * @timer:	timer to wait for
+ *
+ * The function waits in case the timers callback function is
+ * currently executed on the waitqueue of the timer base. The
+ * waitqueue is woken up after the timer callback function has
+ * finished execution.
+ */
+void hrtimer_wait_for_timer(const struct hrtimer *timer)
+{
+	struct hrtimer_clock_base *base = timer->base;
+
+	if (base && base->cpu_base && !timer->irqsafe)
+		wait_event(base->cpu_base->wait,
+			   !(timer->state & HRTIMER_STATE_CALLBACK));
+}
+
+#else
+# define wake_up_timer_waiters(b)	do { } while (0)
+#endif
+
 /*
  * enqueue_hrtimer - internal function to (re)start a timer
  *
@@ -862,6 +952,11 @@
 	if (!(timer->state & HRTIMER_STATE_ENQUEUED))
 		goto out;
 
+	if (unlikely(!list_empty(&timer->cb_entry))) {
+		list_del_init(&timer->cb_entry);
+		goto out;
+	}
+
 	next_timer = timerqueue_getnext(&base->active);
 	timerqueue_del(&base->active, &timer->node);
 	if (&timer->node == next_timer) {
@@ -949,7 +1044,16 @@
 	new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED);
 
 	timer_stats_hrtimer_set_start_info(timer);
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+	{
+		ktime_t now = new_base->get_time();
 
+		if (ktime_to_ns(tim) < ktime_to_ns(now))
+			timer->praecox = now;
+		else
+			timer->praecox = ktime_set(0, 0);
+	}
+#endif
 	leftmost = enqueue_hrtimer(timer, new_base);
 
 	if (!leftmost) {
@@ -963,15 +1067,26 @@
 		 * on dynticks target.
 		 */
 		wake_up_nohz_cpu(new_base->cpu_base->cpu);
-	} else if (new_base->cpu_base == this_cpu_ptr(&hrtimer_bases) &&
-			hrtimer_reprogram(timer, new_base)) {
+	} else if (new_base->cpu_base == this_cpu_ptr(&hrtimer_bases)) {
+
+		ret = hrtimer_enqueue_reprogram(timer, new_base, wakeup);
+		if (ret < 0) {
+			/*
+			 * In case we failed to reprogram the timer (mostly
+			 * because out current timer is already elapsed),
+			 * remove it again and report a failure. This avoids
+			 * stale base->first entries.
+			 */
+			debug_deactivate(timer);
+			__remove_hrtimer(timer, new_base,
+				timer->state & HRTIMER_STATE_CALLBACK, 0);
+		} else if (ret > 0) {
 		/*
 		 * Only allow reprogramming if the new base is on this CPU.
 		 * (it might still be on another CPU if the timer was pending)
 		 *
 		 * XXX send_remote_softirq() ?
 		 */
-		if (wakeup) {
 			/*
 			 * We need to drop cpu_base->lock to avoid a
 			 * lock ordering issue vs. rq->lock.
@@ -979,9 +1094,7 @@
 			raw_spin_unlock(&new_base->cpu_base->lock);
 			raise_softirq_irqoff(HRTIMER_SOFTIRQ);
 			local_irq_restore(flags);
-			return ret;
-		} else {
-			__raise_softirq_irqoff(HRTIMER_SOFTIRQ);
+			return 0;
 		}
 	}
 
@@ -1072,7 +1185,7 @@
 
 		if (ret >= 0)
 			return ret;
-		cpu_relax();
+		hrtimer_wait_for_timer(timer);
 	}
 }
 EXPORT_SYMBOL_GPL(hrtimer_cancel);
@@ -1151,6 +1264,7 @@
 
 	base = hrtimer_clockid_to_base(clock_id);
 	timer->base = &cpu_base->clock_base[base];
+	INIT_LIST_HEAD(&timer->cb_entry);
 	timerqueue_init(&timer->node);
 
 #ifdef CONFIG_TIMER_STATS
@@ -1234,6 +1348,126 @@
 	timer->state &= ~HRTIMER_STATE_CALLBACK;
 }
 
+static enum hrtimer_restart hrtimer_wakeup(struct hrtimer *timer);
+
+#ifdef CONFIG_PREEMPT_RT_BASE
+static void hrtimer_rt_reprogram(int restart, struct hrtimer *timer,
+				 struct hrtimer_clock_base *base)
+{
+	/*
+	 * Note, we clear the callback flag before we requeue the
+	 * timer otherwise we trigger the callback_running() check
+	 * in hrtimer_reprogram().
+	 */
+	timer->state &= ~HRTIMER_STATE_CALLBACK;
+
+	if (restart != HRTIMER_NORESTART) {
+		BUG_ON(hrtimer_active(timer));
+		/*
+		 * Enqueue the timer, if it's the leftmost timer then
+		 * we need to reprogram it.
+		 */
+		if (!enqueue_hrtimer(timer, base))
+			return;
+
+#ifndef CONFIG_HIGH_RES_TIMERS
+	}
+#else
+		if (base->cpu_base->hres_active &&
+		    hrtimer_reprogram(timer, base))
+			goto requeue;
+
+	} else if (hrtimer_active(timer)) {
+		/*
+		 * If the timer was rearmed on another CPU, reprogram
+		 * the event device.
+		 */
+		if (&timer->node == base->active.next &&
+		    base->cpu_base->hres_active &&
+		    hrtimer_reprogram(timer, base))
+			goto requeue;
+	}
+	return;
+
+requeue:
+	/*
+	 * Timer is expired. Thus move it from tree to pending list
+	 * again.
+	 */
+	__remove_hrtimer(timer, base, timer->state, 0);
+	list_add_tail(&timer->cb_entry, &base->expired);
+#endif
+}
+
+/*
+ * The changes in mainline which removed the callback modes from
+ * hrtimer are not yet working with -rt. The non wakeup_process()
+ * based callbacks which involve sleeping locks need to be treated
+ * seperately.
+ */
+static void hrtimer_rt_run_pending(void)
+{
+	enum hrtimer_restart (*fn)(struct hrtimer *);
+	struct hrtimer_cpu_base *cpu_base;
+	struct hrtimer_clock_base *base;
+	struct hrtimer *timer;
+	int index, restart;
+
+	local_irq_disable();
+	cpu_base = &per_cpu(hrtimer_bases, smp_processor_id());
+
+	raw_spin_lock(&cpu_base->lock);
+
+	for (index = 0; index < HRTIMER_MAX_CLOCK_BASES; index++) {
+		base = &cpu_base->clock_base[index];
+
+		while (!list_empty(&base->expired)) {
+			timer = list_first_entry(&base->expired,
+						 struct hrtimer, cb_entry);
+
+			/*
+			 * Same as the above __run_hrtimer function
+			 * just we run with interrupts enabled.
+			 */
+			debug_hrtimer_deactivate(timer);
+			__remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0);
+			timer_stats_account_hrtimer(timer);
+			fn = timer->function;
+
+			raw_spin_unlock_irq(&cpu_base->lock);
+			restart = fn(timer);
+			raw_spin_lock_irq(&cpu_base->lock);
+
+			hrtimer_rt_reprogram(restart, timer, base);
+		}
+	}
+
+	raw_spin_unlock_irq(&cpu_base->lock);
+
+	wake_up_timer_waiters(cpu_base);
+}
+
+static int hrtimer_rt_defer(struct hrtimer *timer)
+{
+	if (timer->irqsafe)
+		return 0;
+
+	__remove_hrtimer(timer, timer->base, timer->state, 0);
+	list_add_tail(&timer->cb_entry, &timer->base->expired);
+	return 1;
+}
+
+#else
+
+static inline void hrtimer_rt_run_pending(void)
+{
+	hrtimer_peek_ahead_timers();
+}
+
+static inline int hrtimer_rt_defer(struct hrtimer *timer) { return 0; }
+
+#endif
+
 #ifdef CONFIG_HIGH_RES_TIMERS
 
 /*
@@ -1244,7 +1478,7 @@
 {
 	struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
 	ktime_t expires_next, now, entry_time, delta;
-	int i, retries = 0;
+	int i, retries = 0, raise = 0;
 
 	BUG_ON(!cpu_base->hres_active);
 	cpu_base->nr_events++;
@@ -1279,6 +1513,15 @@
 
 			timer = container_of(node, struct hrtimer, node);
 
+			trace_hrtimer_interrupt(raw_smp_processor_id(),
+			    ktime_to_ns(ktime_sub(ktime_to_ns(timer->praecox) ?
+				timer->praecox : hrtimer_get_expires(timer),
+				basenow)),
+			    current,
+			    timer->function == hrtimer_wakeup ?
+			    container_of(timer, struct hrtimer_sleeper,
+				timer)->task : NULL);
+
 			/*
 			 * The immediate goal for using the softexpires is
 			 * minimizing wakeups, not running timers at the
@@ -1304,7 +1547,10 @@
 				break;
 			}
 
-			__run_hrtimer(timer, &basenow);
+			if (!hrtimer_rt_defer(timer))
+				__run_hrtimer(timer, &basenow);
+			else
+				raise = 1;
 		}
 	}
 
@@ -1319,7 +1565,7 @@
 	if (expires_next.tv64 == KTIME_MAX ||
 	    !tick_program_event(expires_next, 0)) {
 		cpu_base->hang_detected = 0;
-		return;
+		goto out;
 	}
 
 	/*
@@ -1363,6 +1609,9 @@
 	tick_program_event(expires_next, 1);
 	printk_once(KERN_WARNING "hrtimer: interrupt took %llu ns\n",
 		    ktime_to_ns(delta));
+out:
+	if (raise)
+		raise_softirq_irqoff(HRTIMER_SOFTIRQ);
 }
 
 /*
@@ -1398,18 +1647,18 @@
 	__hrtimer_peek_ahead_timers();
 	local_irq_restore(flags);
 }
-
-static void run_hrtimer_softirq(struct softirq_action *h)
-{
-	hrtimer_peek_ahead_timers();
-}
-
 #else /* CONFIG_HIGH_RES_TIMERS */
 
 static inline void __hrtimer_peek_ahead_timers(void) { }
 
 #endif	/* !CONFIG_HIGH_RES_TIMERS */
 
+
+static void run_hrtimer_softirq(struct softirq_action *h)
+{
+	hrtimer_rt_run_pending();
+}
+
 /*
  * Called from timer softirq every jiffy, expire hrtimers:
  *
@@ -1442,7 +1691,7 @@
 	struct timerqueue_node *node;
 	struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
 	struct hrtimer_clock_base *base;
-	int index, gettime = 1;
+	int index, gettime = 1, raise = 0;
 
 	if (hrtimer_hres_active())
 		return;
@@ -1467,10 +1716,16 @@
 					hrtimer_get_expires_tv64(timer))
 				break;
 
-			__run_hrtimer(timer, &base->softirq_time);
+			if (!hrtimer_rt_defer(timer))
+				__run_hrtimer(timer, &base->softirq_time);
+			else
+				raise = 1;
 		}
 		raw_spin_unlock(&cpu_base->lock);
 	}
+
+	if (raise)
+		raise_softirq_irqoff(HRTIMER_SOFTIRQ);
 }
 
 /*
@@ -1492,16 +1747,18 @@
 void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task)
 {
 	sl->timer.function = hrtimer_wakeup;
+	sl->timer.irqsafe = 1;
 	sl->task = task;
 }
 EXPORT_SYMBOL_GPL(hrtimer_init_sleeper);
 
-static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode)
+static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode,
+				unsigned long state)
 {
 	hrtimer_init_sleeper(t, current);
 
 	do {
-		set_current_state(TASK_INTERRUPTIBLE);
+		set_current_state(state);
 		hrtimer_start_expires(&t->timer, mode);
 		if (!hrtimer_active(&t->timer))
 			t->task = NULL;
@@ -1545,7 +1802,8 @@
 				HRTIMER_MODE_ABS);
 	hrtimer_set_expires_tv64(&t.timer, restart->nanosleep.expires);
 
-	if (do_nanosleep(&t, HRTIMER_MODE_ABS))
+	/* cpu_chill() does not care about restart state. */
+	if (do_nanosleep(&t, HRTIMER_MODE_ABS, TASK_INTERRUPTIBLE))
 		goto out;
 
 	rmtp = restart->nanosleep.rmtp;
@@ -1562,8 +1820,10 @@
 	return ret;
 }
 
-long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
-		       const enum hrtimer_mode mode, const clockid_t clockid)
+static long
+__hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
+		    const enum hrtimer_mode mode, const clockid_t clockid,
+		    unsigned long state)
 {
 	struct restart_block *restart;
 	struct hrtimer_sleeper t;
@@ -1576,7 +1836,7 @@
 
 	hrtimer_init_on_stack(&t.timer, clockid, mode);
 	hrtimer_set_expires_range_ns(&t.timer, timespec_to_ktime(*rqtp), slack);
-	if (do_nanosleep(&t, mode))
+	if (do_nanosleep(&t, mode, state))
 		goto out;
 
 	/* Absolute timers do not update the rmtp value and restart: */
@@ -1603,6 +1863,12 @@
 	return ret;
 }
 
+long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
+		       const enum hrtimer_mode mode, const clockid_t clockid)
+{
+	return __hrtimer_nanosleep(rqtp, rmtp, mode, clockid, TASK_INTERRUPTIBLE);
+}
+
 SYSCALL_DEFINE2(nanosleep, struct timespec __user *, rqtp,
 		struct timespec __user *, rmtp)
 {
@@ -1617,6 +1883,26 @@
 	return hrtimer_nanosleep(&tu, rmtp, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
 }
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * Sleep for 1 ms in hope whoever holds what we want will let it go.
+ */
+void cpu_chill(void)
+{
+	struct timespec tu = {
+		.tv_nsec = NSEC_PER_MSEC,
+	};
+	unsigned int freeze_flag = current->flags & PF_NOFREEZE;
+
+	current->flags |= PF_NOFREEZE;
+	__hrtimer_nanosleep(&tu, NULL, HRTIMER_MODE_REL, CLOCK_MONOTONIC,
+			    TASK_UNINTERRUPTIBLE);
+	if (!freeze_flag)
+		current->flags &= ~PF_NOFREEZE;
+}
+EXPORT_SYMBOL(cpu_chill);
+#endif
+
 /*
  * Functions related to boot-time initialization:
  */
@@ -1628,10 +1914,14 @@
 	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
 		cpu_base->clock_base[i].cpu_base = cpu_base;
 		timerqueue_init_head(&cpu_base->clock_base[i].active);
+		INIT_LIST_HEAD(&cpu_base->clock_base[i].expired);
 	}
 
 	cpu_base->cpu = cpu;
 	hrtimer_init_hres(cpu_base);
+#ifdef CONFIG_PREEMPT_RT_BASE
+	init_waitqueue_head(&cpu_base->wait);
+#endif
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -1744,9 +2034,7 @@
 	hrtimer_cpu_notify(&hrtimers_nb, (unsigned long)CPU_UP_PREPARE,
 			  (void *)(long)smp_processor_id());
 	register_cpu_notifier(&hrtimers_nb);
-#ifdef CONFIG_HIGH_RES_TIMERS
 	open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq);
-#endif
 }
 
 /**
diff -Nur linux-3.18.12.orig/kernel/time/itimer.c linux-3.18.12/kernel/time/itimer.c
--- linux-3.18.12.orig/kernel/time/itimer.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/time/itimer.c	2015-04-26 13:32:22.451684003 -0500
@@ -213,6 +213,7 @@
 		/* We are sharing ->siglock with it_real_fn() */
 		if (hrtimer_try_to_cancel(timer) < 0) {
 			spin_unlock_irq(&tsk->sighand->siglock);
+			hrtimer_wait_for_timer(&tsk->signal->real_timer);
 			goto again;
 		}
 		expires = timeval_to_ktime(value->it_value);
diff -Nur linux-3.18.12.orig/kernel/time/jiffies.c linux-3.18.12/kernel/time/jiffies.c
--- linux-3.18.12.orig/kernel/time/jiffies.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/time/jiffies.c	2015-04-26 13:32:22.451684003 -0500
@@ -73,7 +73,8 @@
 	.shift		= JIFFIES_SHIFT,
 };
 
-__cacheline_aligned_in_smp DEFINE_SEQLOCK(jiffies_lock);
+__cacheline_aligned_in_smp DEFINE_RAW_SPINLOCK(jiffies_lock);
+__cacheline_aligned_in_smp seqcount_t jiffies_seq;
 
 #if (BITS_PER_LONG < 64)
 u64 get_jiffies_64(void)
@@ -82,9 +83,9 @@
 	u64 ret;
 
 	do {
-		seq = read_seqbegin(&jiffies_lock);
+		seq = read_seqcount_begin(&jiffies_seq);
 		ret = jiffies_64;
-	} while (read_seqretry(&jiffies_lock, seq));
+	} while (read_seqcount_retry(&jiffies_seq, seq));
 	return ret;
 }
 EXPORT_SYMBOL(get_jiffies_64);
diff -Nur linux-3.18.12.orig/kernel/time/ntp.c linux-3.18.12/kernel/time/ntp.c
--- linux-3.18.12.orig/kernel/time/ntp.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/time/ntp.c	2015-04-26 13:32:22.451684003 -0500
@@ -10,6 +10,7 @@
 #include <linux/workqueue.h>
 #include <linux/hrtimer.h>
 #include <linux/jiffies.h>
+#include <linux/kthread.h>
 #include <linux/math64.h>
 #include <linux/timex.h>
 #include <linux/time.h>
@@ -519,10 +520,52 @@
 			   &sync_cmos_work, timespec_to_jiffies(&next));
 }
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * RT can not call schedule_delayed_work from real interrupt context.
+ * Need to make a thread to do the real work.
+ */
+static struct task_struct *cmos_delay_thread;
+static bool do_cmos_delay;
+
+static int run_cmos_delay(void *ignore)
+{
+	while (!kthread_should_stop()) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		if (do_cmos_delay) {
+			do_cmos_delay = false;
+			queue_delayed_work(system_power_efficient_wq,
+					   &sync_cmos_work, 0);
+		}
+		schedule();
+	}
+	__set_current_state(TASK_RUNNING);
+	return 0;
+}
+
+void ntp_notify_cmos_timer(void)
+{
+	do_cmos_delay = true;
+	/* Make visible before waking up process */
+	smp_wmb();
+	wake_up_process(cmos_delay_thread);
+}
+
+static __init int create_cmos_delay_thread(void)
+{
+	cmos_delay_thread = kthread_run(run_cmos_delay, NULL, "kcmosdelayd");
+	BUG_ON(!cmos_delay_thread);
+	return 0;
+}
+early_initcall(create_cmos_delay_thread);
+
+#else
+
 void ntp_notify_cmos_timer(void)
 {
 	queue_delayed_work(system_power_efficient_wq, &sync_cmos_work, 0);
 }
+#endif /* CONFIG_PREEMPT_RT_FULL */
 
 #else
 void ntp_notify_cmos_timer(void) { }
diff -Nur linux-3.18.12.orig/kernel/time/posix-cpu-timers.c linux-3.18.12/kernel/time/posix-cpu-timers.c
--- linux-3.18.12.orig/kernel/time/posix-cpu-timers.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/time/posix-cpu-timers.c	2015-04-26 13:32:22.451684003 -0500
@@ -3,6 +3,7 @@
  */
 
 #include <linux/sched.h>
+#include <linux/sched/rt.h>
 #include <linux/posix-timers.h>
 #include <linux/errno.h>
 #include <linux/math64.h>
@@ -626,7 +627,7 @@
 	/*
 	 * Disarm any old timer after extracting its expiry time.
 	 */
-	WARN_ON_ONCE(!irqs_disabled());
+	WARN_ON_ONCE_NONRT(!irqs_disabled());
 
 	ret = 0;
 	old_incr = timer->it.cpu.incr;
@@ -1047,7 +1048,7 @@
 	/*
 	 * Now re-arm for the new expiry time.
 	 */
-	WARN_ON_ONCE(!irqs_disabled());
+	WARN_ON_ONCE_NONRT(!irqs_disabled());
 	arm_timer(timer);
 	unlock_task_sighand(p, &flags);
 
@@ -1113,10 +1114,11 @@
 	sig = tsk->signal;
 	if (sig->cputimer.running) {
 		struct task_cputime group_sample;
+		unsigned long flags;
 
-		raw_spin_lock(&sig->cputimer.lock);
+		raw_spin_lock_irqsave(&sig->cputimer.lock, flags);
 		group_sample = sig->cputimer.cputime;
-		raw_spin_unlock(&sig->cputimer.lock);
+		raw_spin_unlock_irqrestore(&sig->cputimer.lock, flags);
 
 		if (task_cputime_expired(&group_sample, &sig->cputime_expires))
 			return 1;
@@ -1130,13 +1132,13 @@
  * already updated our counts.  We need to check if any timers fire now.
  * Interrupts are disabled.
  */
-void run_posix_cpu_timers(struct task_struct *tsk)
+static void __run_posix_cpu_timers(struct task_struct *tsk)
 {
 	LIST_HEAD(firing);
 	struct k_itimer *timer, *next;
 	unsigned long flags;
 
-	WARN_ON_ONCE(!irqs_disabled());
+	WARN_ON_ONCE_NONRT(!irqs_disabled());
 
 	/*
 	 * The fast path checks that there are no expired thread or thread
@@ -1194,6 +1196,190 @@
 	}
 }
 
+#ifdef CONFIG_PREEMPT_RT_BASE
+#include <linux/kthread.h>
+#include <linux/cpu.h>
+DEFINE_PER_CPU(struct task_struct *, posix_timer_task);
+DEFINE_PER_CPU(struct task_struct *, posix_timer_tasklist);
+
+static int posix_cpu_timers_thread(void *data)
+{
+	int cpu = (long)data;
+
+	BUG_ON(per_cpu(posix_timer_task,cpu) != current);
+
+	while (!kthread_should_stop()) {
+		struct task_struct *tsk = NULL;
+		struct task_struct *next = NULL;
+
+		if (cpu_is_offline(cpu))
+			goto wait_to_die;
+
+		/* grab task list */
+		raw_local_irq_disable();
+		tsk = per_cpu(posix_timer_tasklist, cpu);
+		per_cpu(posix_timer_tasklist, cpu) = NULL;
+		raw_local_irq_enable();
+
+		/* its possible the list is empty, just return */
+		if (!tsk) {
+			set_current_state(TASK_INTERRUPTIBLE);
+			schedule();
+			__set_current_state(TASK_RUNNING);
+			continue;
+		}
+
+		/* Process task list */
+		while (1) {
+			/* save next */
+			next = tsk->posix_timer_list;
+
+			/* run the task timers, clear its ptr and
+			 * unreference it
+			 */
+			__run_posix_cpu_timers(tsk);
+			tsk->posix_timer_list = NULL;
+			put_task_struct(tsk);
+
+			/* check if this is the last on the list */
+			if (next == tsk)
+				break;
+			tsk = next;
+		}
+	}
+	return 0;
+
+wait_to_die:
+	/* Wait for kthread_stop */
+	set_current_state(TASK_INTERRUPTIBLE);
+	while (!kthread_should_stop()) {
+		schedule();
+		set_current_state(TASK_INTERRUPTIBLE);
+	}
+	__set_current_state(TASK_RUNNING);
+	return 0;
+}
+
+static inline int __fastpath_timer_check(struct task_struct *tsk)
+{
+	/* tsk == current, ensure it is safe to use ->signal/sighand */
+	if (unlikely(tsk->exit_state))
+		return 0;
+
+	if (!task_cputime_zero(&tsk->cputime_expires))
+			return 1;
+
+	if (!task_cputime_zero(&tsk->signal->cputime_expires))
+			return 1;
+
+	return 0;
+}
+
+void run_posix_cpu_timers(struct task_struct *tsk)
+{
+	unsigned long cpu = smp_processor_id();
+	struct task_struct *tasklist;
+
+	BUG_ON(!irqs_disabled());
+	if(!per_cpu(posix_timer_task, cpu))
+		return;
+	/* get per-cpu references */
+	tasklist = per_cpu(posix_timer_tasklist, cpu);
+
+	/* check to see if we're already queued */
+	if (!tsk->posix_timer_list && __fastpath_timer_check(tsk)) {
+		get_task_struct(tsk);
+		if (tasklist) {
+			tsk->posix_timer_list = tasklist;
+		} else {
+			/*
+			 * The list is terminated by a self-pointing
+			 * task_struct
+			 */
+			tsk->posix_timer_list = tsk;
+		}
+		per_cpu(posix_timer_tasklist, cpu) = tsk;
+
+		wake_up_process(per_cpu(posix_timer_task, cpu));
+	}
+}
+
+/*
+ * posix_cpu_thread_call - callback that gets triggered when a CPU is added.
+ * Here we can start up the necessary migration thread for the new CPU.
+ */
+static int posix_cpu_thread_call(struct notifier_block *nfb,
+				 unsigned long action, void *hcpu)
+{
+	int cpu = (long)hcpu;
+	struct task_struct *p;
+	struct sched_param param;
+
+	switch (action) {
+	case CPU_UP_PREPARE:
+		p = kthread_create(posix_cpu_timers_thread, hcpu,
+					"posixcputmr/%d",cpu);
+		if (IS_ERR(p))
+			return NOTIFY_BAD;
+		p->flags |= PF_NOFREEZE;
+		kthread_bind(p, cpu);
+		/* Must be high prio to avoid getting starved */
+		param.sched_priority = MAX_RT_PRIO-1;
+		sched_setscheduler(p, SCHED_FIFO, &param);
+		per_cpu(posix_timer_task,cpu) = p;
+		break;
+	case CPU_ONLINE:
+		/* Strictly unneccessary, as first user will wake it. */
+		wake_up_process(per_cpu(posix_timer_task,cpu));
+		break;
+#ifdef CONFIG_HOTPLUG_CPU
+	case CPU_UP_CANCELED:
+		/* Unbind it from offline cpu so it can run.  Fall thru. */
+		kthread_bind(per_cpu(posix_timer_task, cpu),
+			     cpumask_any(cpu_online_mask));
+		kthread_stop(per_cpu(posix_timer_task,cpu));
+		per_cpu(posix_timer_task,cpu) = NULL;
+		break;
+	case CPU_DEAD:
+		kthread_stop(per_cpu(posix_timer_task,cpu));
+		per_cpu(posix_timer_task,cpu) = NULL;
+		break;
+#endif
+	}
+	return NOTIFY_OK;
+}
+
+/* Register at highest priority so that task migration (migrate_all_tasks)
+ * happens before everything else.
+ */
+static struct notifier_block posix_cpu_thread_notifier = {
+	.notifier_call = posix_cpu_thread_call,
+	.priority = 10
+};
+
+static int __init posix_cpu_thread_init(void)
+{
+	void *hcpu = (void *)(long)smp_processor_id();
+	/* Start one for boot CPU. */
+	unsigned long cpu;
+
+	/* init the per-cpu posix_timer_tasklets */
+	for_each_possible_cpu(cpu)
+		per_cpu(posix_timer_tasklist, cpu) = NULL;
+
+	posix_cpu_thread_call(&posix_cpu_thread_notifier, CPU_UP_PREPARE, hcpu);
+	posix_cpu_thread_call(&posix_cpu_thread_notifier, CPU_ONLINE, hcpu);
+	register_cpu_notifier(&posix_cpu_thread_notifier);
+	return 0;
+}
+early_initcall(posix_cpu_thread_init);
+#else /* CONFIG_PREEMPT_RT_BASE */
+void run_posix_cpu_timers(struct task_struct *tsk)
+{
+	__run_posix_cpu_timers(tsk);
+}
+#endif /* CONFIG_PREEMPT_RT_BASE */
+
 /*
  * Set one of the process-wide special case CPU timers or RLIMIT_CPU.
  * The tsk->sighand->siglock must be held by the caller.
diff -Nur linux-3.18.12.orig/kernel/time/posix-timers.c linux-3.18.12/kernel/time/posix-timers.c
--- linux-3.18.12.orig/kernel/time/posix-timers.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/time/posix-timers.c	2015-04-26 13:32:22.451684003 -0500
@@ -499,6 +499,7 @@
 static struct pid *good_sigevent(sigevent_t * event)
 {
 	struct task_struct *rtn = current->group_leader;
+	int sig = event->sigev_signo;
 
 	if ((event->sigev_notify & SIGEV_THREAD_ID ) &&
 		(!(rtn = find_task_by_vpid(event->sigev_notify_thread_id)) ||
@@ -507,7 +508,8 @@
 		return NULL;
 
 	if (((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) &&
-	    ((event->sigev_signo <= 0) || (event->sigev_signo > SIGRTMAX)))
+	    (sig <= 0 || sig > SIGRTMAX || sig_kernel_only(sig) ||
+	     sig_kernel_coredump(sig)))
 		return NULL;
 
 	return task_pid(rtn);
@@ -819,6 +821,20 @@
 	return overrun;
 }
 
+/*
+ * Protected by RCU!
+ */
+static void timer_wait_for_callback(struct k_clock *kc, struct k_itimer *timr)
+{
+#ifdef CONFIG_PREEMPT_RT_FULL
+	if (kc->timer_set == common_timer_set)
+		hrtimer_wait_for_timer(&timr->it.real.timer);
+	else
+		/* FIXME: Whacky hack for posix-cpu-timers */
+		schedule_timeout(1);
+#endif
+}
+
 /* Set a POSIX.1b interval timer. */
 /* timr->it_lock is taken. */
 static int
@@ -896,6 +912,7 @@
 	if (!timr)
 		return -EINVAL;
 
+	rcu_read_lock();
 	kc = clockid_to_kclock(timr->it_clock);
 	if (WARN_ON_ONCE(!kc || !kc->timer_set))
 		error = -EINVAL;
@@ -904,9 +921,12 @@
 
 	unlock_timer(timr, flag);
 	if (error == TIMER_RETRY) {
+		timer_wait_for_callback(kc, timr);
 		rtn = NULL;	// We already got the old time...
+		rcu_read_unlock();
 		goto retry;
 	}
+	rcu_read_unlock();
 
 	if (old_setting && !error &&
 	    copy_to_user(old_setting, &old_spec, sizeof (old_spec)))
@@ -944,10 +964,15 @@
 	if (!timer)
 		return -EINVAL;
 
+	rcu_read_lock();
 	if (timer_delete_hook(timer) == TIMER_RETRY) {
 		unlock_timer(timer, flags);
+		timer_wait_for_callback(clockid_to_kclock(timer->it_clock),
+					timer);
+		rcu_read_unlock();
 		goto retry_delete;
 	}
+	rcu_read_unlock();
 
 	spin_lock(&current->sighand->siglock);
 	list_del(&timer->list);
@@ -973,8 +998,18 @@
 retry_delete:
 	spin_lock_irqsave(&timer->it_lock, flags);
 
+	/* On RT we can race with a deletion */
+	if (!timer->it_signal) {
+		unlock_timer(timer, flags);
+		return;
+	}
+
 	if (timer_delete_hook(timer) == TIMER_RETRY) {
+		rcu_read_lock();
 		unlock_timer(timer, flags);
+		timer_wait_for_callback(clockid_to_kclock(timer->it_clock),
+					timer);
+		rcu_read_unlock();
 		goto retry_delete;
 	}
 	list_del(&timer->list);
diff -Nur linux-3.18.12.orig/kernel/time/tick-common.c linux-3.18.12/kernel/time/tick-common.c
--- linux-3.18.12.orig/kernel/time/tick-common.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/time/tick-common.c	2015-04-26 13:32:22.451684003 -0500
@@ -78,13 +78,15 @@
 static void tick_periodic(int cpu)
 {
 	if (tick_do_timer_cpu == cpu) {
-		write_seqlock(&jiffies_lock);
+		raw_spin_lock(&jiffies_lock);
+		write_seqcount_begin(&jiffies_seq);
 
 		/* Keep track of the next tick event */
 		tick_next_period = ktime_add(tick_next_period, tick_period);
 
 		do_timer(1);
-		write_sequnlock(&jiffies_lock);
+		write_seqcount_end(&jiffies_seq);
+		raw_spin_unlock(&jiffies_lock);
 		update_wall_time();
 	}
 
@@ -146,9 +148,9 @@
 		ktime_t next;
 
 		do {
-			seq = read_seqbegin(&jiffies_lock);
+			seq = read_seqcount_begin(&jiffies_seq);
 			next = tick_next_period;
-		} while (read_seqretry(&jiffies_lock, seq));
+		} while (read_seqcount_retry(&jiffies_seq, seq));
 
 		clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT);
 
diff -Nur linux-3.18.12.orig/kernel/time/tick-internal.h linux-3.18.12/kernel/time/tick-internal.h
--- linux-3.18.12.orig/kernel/time/tick-internal.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/time/tick-internal.h	2015-04-26 13:32:22.451684003 -0500
@@ -6,7 +6,8 @@
 
 #include "timekeeping.h"
 
-extern seqlock_t jiffies_lock;
+extern raw_spinlock_t jiffies_lock;
+extern seqcount_t jiffies_seq;
 
 #define CS_NAME_LEN	32
 
diff -Nur linux-3.18.12.orig/kernel/time/tick-sched.c linux-3.18.12/kernel/time/tick-sched.c
--- linux-3.18.12.orig/kernel/time/tick-sched.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/time/tick-sched.c	2015-04-26 13:32:22.451684003 -0500
@@ -62,7 +62,8 @@
 		return;
 
 	/* Reevalute with jiffies_lock held */
-	write_seqlock(&jiffies_lock);
+	raw_spin_lock(&jiffies_lock);
+	write_seqcount_begin(&jiffies_seq);
 
 	delta = ktime_sub(now, last_jiffies_update);
 	if (delta.tv64 >= tick_period.tv64) {
@@ -85,10 +86,12 @@
 		/* Keep the tick_next_period variable up to date */
 		tick_next_period = ktime_add(last_jiffies_update, tick_period);
 	} else {
-		write_sequnlock(&jiffies_lock);
+		write_seqcount_end(&jiffies_seq);
+		raw_spin_unlock(&jiffies_lock);
 		return;
 	}
-	write_sequnlock(&jiffies_lock);
+	write_seqcount_end(&jiffies_seq);
+	raw_spin_unlock(&jiffies_lock);
 	update_wall_time();
 }
 
@@ -99,12 +102,14 @@
 {
 	ktime_t period;
 
-	write_seqlock(&jiffies_lock);
+	raw_spin_lock(&jiffies_lock);
+	write_seqcount_begin(&jiffies_seq);
 	/* Did we start the jiffies update yet ? */
 	if (last_jiffies_update.tv64 == 0)
 		last_jiffies_update = tick_next_period;
 	period = last_jiffies_update;
-	write_sequnlock(&jiffies_lock);
+	write_seqcount_end(&jiffies_seq);
+	raw_spin_unlock(&jiffies_lock);
 	return period;
 }
 
@@ -176,6 +181,11 @@
 		return false;
 	}
 
+	if (!arch_irq_work_has_interrupt()) {
+		trace_tick_stop(0, "missing irq work interrupt\n");
+		return false;
+	}
+
 	/* sched_clock_tick() needs us? */
 #ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
 	/*
@@ -217,11 +227,17 @@
 
 static void nohz_full_kick_work_func(struct irq_work *work)
 {
+	unsigned long flags;
+
+	/* ksoftirqd processes sirqs with interrupts enabled */
+	local_irq_save(flags);
 	__tick_nohz_full_check();
+	local_irq_restore(flags);
 }
 
 static DEFINE_PER_CPU(struct irq_work, nohz_full_kick_work) = {
 	.func = nohz_full_kick_work_func,
+	.flags = IRQ_WORK_HARD_IRQ,
 };
 
 /*
@@ -580,10 +596,10 @@
 
 	/* Read jiffies and the time when jiffies were updated last */
 	do {
-		seq = read_seqbegin(&jiffies_lock);
+		seq = read_seqcount_begin(&jiffies_seq);
 		last_update = last_jiffies_update;
 		last_jiffies = jiffies;
-	} while (read_seqretry(&jiffies_lock, seq));
+	} while (read_seqcount_retry(&jiffies_seq, seq));
 
 	if (rcu_needs_cpu(cpu, &rcu_delta_jiffies) ||
 	    arch_needs_cpu() || irq_work_needs_cpu()) {
@@ -761,14 +777,7 @@
 		return false;
 
 	if (unlikely(local_softirq_pending() && cpu_online(cpu))) {
-		static int ratelimit;
-
-		if (ratelimit < 10 &&
-		    (local_softirq_pending() & SOFTIRQ_STOP_IDLE_MASK)) {
-			pr_warn("NOHZ: local_softirq_pending %02x\n",
-				(unsigned int) local_softirq_pending());
-			ratelimit++;
-		}
+		softirq_check_pending_idle();
 		return false;
 	}
 
@@ -1156,6 +1165,7 @@
 	 * Emulate tick processing via per-CPU hrtimers:
 	 */
 	hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+	ts->sched_timer.irqsafe = 1;
 	ts->sched_timer.function = tick_sched_timer;
 
 	/* Get the next period (per cpu) */
diff -Nur linux-3.18.12.orig/kernel/time/timekeeping.c linux-3.18.12/kernel/time/timekeeping.c
--- linux-3.18.12.orig/kernel/time/timekeeping.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/time/timekeeping.c	2015-04-26 13:32:22.451684003 -0500
@@ -1814,8 +1814,10 @@
  */
 void xtime_update(unsigned long ticks)
 {
-	write_seqlock(&jiffies_lock);
+	raw_spin_lock(&jiffies_lock);
+	write_seqcount_begin(&jiffies_seq);
 	do_timer(ticks);
-	write_sequnlock(&jiffies_lock);
+	write_seqcount_end(&jiffies_seq);
+	raw_spin_unlock(&jiffies_lock);
 	update_wall_time();
 }
diff -Nur linux-3.18.12.orig/kernel/time/timer.c linux-3.18.12/kernel/time/timer.c
--- linux-3.18.12.orig/kernel/time/timer.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/time/timer.c	2015-04-26 13:32:22.455684003 -0500
@@ -78,6 +78,9 @@
 struct tvec_base {
 	spinlock_t lock;
 	struct timer_list *running_timer;
+#ifdef CONFIG_PREEMPT_RT_FULL
+	wait_queue_head_t wait_for_running_timer;
+#endif
 	unsigned long timer_jiffies;
 	unsigned long next_timer;
 	unsigned long active_timers;
@@ -758,6 +761,36 @@
 	}
 }
 
+#ifndef CONFIG_PREEMPT_RT_FULL
+static inline struct tvec_base *switch_timer_base(struct timer_list *timer,
+						  struct tvec_base *old,
+						  struct tvec_base *new)
+{
+	/* See the comment in lock_timer_base() */
+	timer_set_base(timer, NULL);
+	spin_unlock(&old->lock);
+	spin_lock(&new->lock);
+	timer_set_base(timer, new);
+	return new;
+}
+#else
+static inline struct tvec_base *switch_timer_base(struct timer_list *timer,
+						  struct tvec_base *old,
+						  struct tvec_base *new)
+{
+	/*
+	 * We cannot do the above because we might be preempted and
+	 * then the preempter would see NULL and loop forever.
+	 */
+	if (spin_trylock(&new->lock)) {
+		timer_set_base(timer, new);
+		spin_unlock(&old->lock);
+		return new;
+	}
+	return old;
+}
+#endif
+
 static inline int
 __mod_timer(struct timer_list *timer, unsigned long expires,
 						bool pending_only, int pinned)
@@ -788,14 +821,8 @@
 		 * handler yet has not finished. This also guarantees that
 		 * the timer is serialized wrt itself.
 		 */
-		if (likely(base->running_timer != timer)) {
-			/* See the comment in lock_timer_base() */
-			timer_set_base(timer, NULL);
-			spin_unlock(&base->lock);
-			base = new_base;
-			spin_lock(&base->lock);
-			timer_set_base(timer, base);
-		}
+		if (likely(base->running_timer != timer))
+			base = switch_timer_base(timer, base, new_base);
 	}
 
 	timer->expires = expires;
@@ -969,6 +996,29 @@
 }
 EXPORT_SYMBOL_GPL(add_timer_on);
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * Wait for a running timer
+ */
+static void wait_for_running_timer(struct timer_list *timer)
+{
+	struct tvec_base *base = timer->base;
+
+	if (base->running_timer == timer)
+		wait_event(base->wait_for_running_timer,
+			   base->running_timer != timer);
+}
+
+# define wakeup_timer_waiters(b)	wake_up(&(b)->wait_for_running_timer)
+#else
+static inline void wait_for_running_timer(struct timer_list *timer)
+{
+	cpu_relax();
+}
+
+# define wakeup_timer_waiters(b)	do { } while (0)
+#endif
+
 /**
  * del_timer - deactive a timer.
  * @timer: the timer to be deactivated
@@ -1026,7 +1076,7 @@
 }
 EXPORT_SYMBOL(try_to_del_timer_sync);
 
-#ifdef CONFIG_SMP
+#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT_FULL)
 /**
  * del_timer_sync - deactivate a timer and wait for the handler to finish.
  * @timer: the timer to be deactivated
@@ -1086,7 +1136,7 @@
 		int ret = try_to_del_timer_sync(timer);
 		if (ret >= 0)
 			return ret;
-		cpu_relax();
+		wait_for_running_timer(timer);
 	}
 }
 EXPORT_SYMBOL(del_timer_sync);
@@ -1207,15 +1257,17 @@
 			if (irqsafe) {
 				spin_unlock(&base->lock);
 				call_timer_fn(timer, fn, data);
+				base->running_timer = NULL;
 				spin_lock(&base->lock);
 			} else {
 				spin_unlock_irq(&base->lock);
 				call_timer_fn(timer, fn, data);
+				base->running_timer = NULL;
 				spin_lock_irq(&base->lock);
 			}
 		}
 	}
-	base->running_timer = NULL;
+	wakeup_timer_waiters(base);
 	spin_unlock_irq(&base->lock);
 }
 
@@ -1355,17 +1407,31 @@
 	if (cpu_is_offline(smp_processor_id()))
 		return expires;
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+	/*
+	 * On PREEMPT_RT we cannot sleep here. If the trylock does not
+	 * succeed then we return the worst-case 'expires in 1 tick'
+	 * value.  We use the rt functions here directly to avoid a
+	 * migrate_disable() call.
+	 */
+	if (!spin_do_trylock(&base->lock))
+		return  now + 1;
+#else
 	spin_lock(&base->lock);
+#endif
 	if (base->active_timers) {
 		if (time_before_eq(base->next_timer, base->timer_jiffies))
 			base->next_timer = __next_timer_interrupt(base);
 		expires = base->next_timer;
 	}
+#ifdef CONFIG_PREEMPT_RT_FULL
+	rt_spin_unlock_after_trylock_in_irq(&base->lock);
+#else
 	spin_unlock(&base->lock);
+#endif
 
 	if (time_before_eq(expires, now))
 		return now;
-
 	return cmp_next_hrtimer_event(now, expires);
 }
 #endif
@@ -1381,13 +1447,13 @@
 
 	/* Note: this timer irq context must be accounted for as well. */
 	account_process_tick(p, user_tick);
+	scheduler_tick();
 	run_local_timers();
 	rcu_check_callbacks(cpu, user_tick);
-#ifdef CONFIG_IRQ_WORK
-	if (in_irq())
-		irq_work_tick();
+
+#if defined(CONFIG_IRQ_WORK) && !defined(CONFIG_PREEMPT_RT_FULL)
+	irq_work_tick();
 #endif
-	scheduler_tick();
 	run_posix_cpu_timers(p);
 }
 
@@ -1400,6 +1466,10 @@
 
 	hrtimer_run_pending();
 
+#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_PREEMPT_RT_FULL)
+	irq_work_tick();
+#endif
+
 	if (time_after_eq(jiffies, base->timer_jiffies))
 		__run_timers(base);
 }
@@ -1574,6 +1644,9 @@
 		base = per_cpu(tvec_bases, cpu);
 	}
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+	init_waitqueue_head(&base->wait_for_running_timer);
+#endif
 
 	for (j = 0; j < TVN_SIZE; j++) {
 		INIT_LIST_HEAD(base->tv5.vec + j);
@@ -1613,7 +1686,7 @@
 
 	BUG_ON(cpu_online(cpu));
 	old_base = per_cpu(tvec_bases, cpu);
-	new_base = get_cpu_var(tvec_bases);
+	new_base = get_local_var(tvec_bases);
 	/*
 	 * The caller is globally serialized and nobody else
 	 * takes two locks at once, deadlock is not possible.
@@ -1634,7 +1707,7 @@
 
 	spin_unlock(&old_base->lock);
 	spin_unlock_irq(&new_base->lock);
-	put_cpu_var(tvec_bases);
+	put_local_var(tvec_bases);
 }
 #endif /* CONFIG_HOTPLUG_CPU */
 
diff -Nur linux-3.18.12.orig/kernel/trace/Kconfig linux-3.18.12/kernel/trace/Kconfig
--- linux-3.18.12.orig/kernel/trace/Kconfig	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/trace/Kconfig	2015-04-26 13:32:22.455684003 -0500
@@ -187,6 +187,24 @@
 	  enabled. This option and the preempt-off timing option can be
 	  used together or separately.)
 
+config INTERRUPT_OFF_HIST
+	bool "Interrupts-off Latency Histogram"
+	depends on IRQSOFF_TRACER
+	help
+	  This option generates continuously updated histograms (one per cpu)
+	  of the duration of time periods with interrupts disabled. The
+	  histograms are disabled by default. To enable them, write a non-zero
+	  number to
+
+	      /sys/kernel/debug/tracing/latency_hist/enable/preemptirqsoff
+
+	  If PREEMPT_OFF_HIST is also selected, additional histograms (one
+	  per cpu) are generated that accumulate the duration of time periods
+	  when both interrupts and preemption are disabled. The histogram data
+	  will be located in the debug file system at
+
+	      /sys/kernel/debug/tracing/latency_hist/irqsoff
+
 config PREEMPT_TRACER
 	bool "Preemption-off Latency Tracer"
 	default n
@@ -211,6 +229,24 @@
 	  enabled. This option and the irqs-off timing option can be
 	  used together or separately.)
 
+config PREEMPT_OFF_HIST
+	bool "Preemption-off Latency Histogram"
+	depends on PREEMPT_TRACER
+	help
+	  This option generates continuously updated histograms (one per cpu)
+	  of the duration of time periods with preemption disabled. The
+	  histograms are disabled by default. To enable them, write a non-zero
+	  number to
+
+	      /sys/kernel/debug/tracing/latency_hist/enable/preemptirqsoff
+
+	  If INTERRUPT_OFF_HIST is also selected, additional histograms (one
+	  per cpu) are generated that accumulate the duration of time periods
+	  when both interrupts and preemption are disabled. The histogram data
+	  will be located in the debug file system at
+
+	      /sys/kernel/debug/tracing/latency_hist/preemptoff
+
 config SCHED_TRACER
 	bool "Scheduling Latency Tracer"
 	select GENERIC_TRACER
@@ -221,6 +257,74 @@
 	  This tracer tracks the latency of the highest priority task
 	  to be scheduled in, starting from the point it has woken up.
 
+config WAKEUP_LATENCY_HIST
+	bool "Scheduling Latency Histogram"
+	depends on SCHED_TRACER
+	help
+	  This option generates continuously updated histograms (one per cpu)
+	  of the scheduling latency of the highest priority task.
+	  The histograms are disabled by default. To enable them, write a
+	  non-zero number to
+
+	      /sys/kernel/debug/tracing/latency_hist/enable/wakeup
+
+	  Two different algorithms are used, one to determine the latency of
+	  processes that exclusively use the highest priority of the system and
+	  another one to determine the latency of processes that share the
+	  highest system priority with other processes. The former is used to
+	  improve hardware and system software, the latter to optimize the
+	  priority design of a given system. The histogram data will be
+	  located in the debug file system at
+
+	      /sys/kernel/debug/tracing/latency_hist/wakeup
+
+	  and
+
+	      /sys/kernel/debug/tracing/latency_hist/wakeup/sharedprio
+
+	  If both Scheduling Latency Histogram and Missed Timer Offsets
+	  Histogram are selected, additional histogram data will be collected
+	  that contain, in addition to the wakeup latency, the timer latency, in
+	  case the wakeup was triggered by an expired timer. These histograms
+	  are available in the
+
+	      /sys/kernel/debug/tracing/latency_hist/timerandwakeup
+
+	  directory. They reflect the apparent interrupt and scheduling latency
+	  and are best suitable to determine the worst-case latency of a given
+	  system. To enable these histograms, write a non-zero number to
+
+	      /sys/kernel/debug/tracing/latency_hist/enable/timerandwakeup
+
+config MISSED_TIMER_OFFSETS_HIST
+	depends on HIGH_RES_TIMERS
+	select GENERIC_TRACER
+	bool "Missed Timer Offsets Histogram"
+	help
+	  Generate a histogram of missed timer offsets in microseconds. The
+	  histograms are disabled by default. To enable them, write a non-zero
+	  number to
+
+	      /sys/kernel/debug/tracing/latency_hist/enable/missed_timer_offsets
+
+	  The histogram data will be located in the debug file system at
+
+	      /sys/kernel/debug/tracing/latency_hist/missed_timer_offsets
+
+	  If both Scheduling Latency Histogram and Missed Timer Offsets
+	  Histogram are selected, additional histogram data will be collected
+	  that contain, in addition to the wakeup latency, the timer latency, in
+	  case the wakeup was triggered by an expired timer. These histograms
+	  are available in the
+
+	      /sys/kernel/debug/tracing/latency_hist/timerandwakeup
+
+	  directory. They reflect the apparent interrupt and scheduling latency
+	  and are best suitable to determine the worst-case latency of a given
+	  system. To enable these histograms, write a non-zero number to
+
+	      /sys/kernel/debug/tracing/latency_hist/enable/timerandwakeup
+
 config ENABLE_DEFAULT_TRACERS
 	bool "Trace process context switches and events"
 	depends on !GENERIC_TRACER
diff -Nur linux-3.18.12.orig/kernel/trace/latency_hist.c linux-3.18.12/kernel/trace/latency_hist.c
--- linux-3.18.12.orig/kernel/trace/latency_hist.c	1969-12-31 18:00:00.000000000 -0600
+++ linux-3.18.12/kernel/trace/latency_hist.c	2015-04-26 13:32:22.455684003 -0500
@@ -0,0 +1,1178 @@
+/*
+ * kernel/trace/latency_hist.c
+ *
+ * Add support for histograms of preemption-off latency and
+ * interrupt-off latency and wakeup latency, it depends on
+ * Real-Time Preemption Support.
+ *
+ *  Copyright (C) 2005 MontaVista Software, Inc.
+ *  Yi Yang <yyang@ch.mvista.com>
+ *
+ *  Converted to work with the new latency tracer.
+ *  Copyright (C) 2008 Red Hat, Inc.
+ *    Steven Rostedt <srostedt@redhat.com>
+ *
+ */
+#include <linux/module.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/percpu.h>
+#include <linux/kallsyms.h>
+#include <linux/uaccess.h>
+#include <linux/sched.h>
+#include <linux/sched/rt.h>
+#include <linux/slab.h>
+#include <linux/atomic.h>
+#include <asm/div64.h>
+
+#include "trace.h"
+#include <trace/events/sched.h>
+
+#define NSECS_PER_USECS 1000L
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/hist.h>
+
+enum {
+	IRQSOFF_LATENCY = 0,
+	PREEMPTOFF_LATENCY,
+	PREEMPTIRQSOFF_LATENCY,
+	WAKEUP_LATENCY,
+	WAKEUP_LATENCY_SHAREDPRIO,
+	MISSED_TIMER_OFFSETS,
+	TIMERANDWAKEUP_LATENCY,
+	MAX_LATENCY_TYPE,
+};
+
+#define MAX_ENTRY_NUM 10240
+
+struct hist_data {
+	atomic_t hist_mode; /* 0 log, 1 don't log */
+	long offset; /* set it to MAX_ENTRY_NUM/2 for a bipolar scale */
+	long min_lat;
+	long max_lat;
+	unsigned long long below_hist_bound_samples;
+	unsigned long long above_hist_bound_samples;
+	long long accumulate_lat;
+	unsigned long long total_samples;
+	unsigned long long hist_array[MAX_ENTRY_NUM];
+};
+
+struct enable_data {
+	int latency_type;
+	int enabled;
+};
+
+static char *latency_hist_dir_root = "latency_hist";
+
+#ifdef CONFIG_INTERRUPT_OFF_HIST
+static DEFINE_PER_CPU(struct hist_data, irqsoff_hist);
+static char *irqsoff_hist_dir = "irqsoff";
+static DEFINE_PER_CPU(cycles_t, hist_irqsoff_start);
+static DEFINE_PER_CPU(int, hist_irqsoff_counting);
+#endif
+
+#ifdef CONFIG_PREEMPT_OFF_HIST
+static DEFINE_PER_CPU(struct hist_data, preemptoff_hist);
+static char *preemptoff_hist_dir = "preemptoff";
+static DEFINE_PER_CPU(cycles_t, hist_preemptoff_start);
+static DEFINE_PER_CPU(int, hist_preemptoff_counting);
+#endif
+
+#if defined(CONFIG_PREEMPT_OFF_HIST) && defined(CONFIG_INTERRUPT_OFF_HIST)
+static DEFINE_PER_CPU(struct hist_data, preemptirqsoff_hist);
+static char *preemptirqsoff_hist_dir = "preemptirqsoff";
+static DEFINE_PER_CPU(cycles_t, hist_preemptirqsoff_start);
+static DEFINE_PER_CPU(int, hist_preemptirqsoff_counting);
+#endif
+
+#if defined(CONFIG_PREEMPT_OFF_HIST) || defined(CONFIG_INTERRUPT_OFF_HIST)
+static notrace void probe_preemptirqsoff_hist(void *v, int reason, int start);
+static struct enable_data preemptirqsoff_enabled_data = {
+	.latency_type = PREEMPTIRQSOFF_LATENCY,
+	.enabled = 0,
+};
+#endif
+
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+	defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+struct maxlatproc_data {
+	char comm[FIELD_SIZEOF(struct task_struct, comm)];
+	char current_comm[FIELD_SIZEOF(struct task_struct, comm)];
+	int pid;
+	int current_pid;
+	int prio;
+	int current_prio;
+	long latency;
+	long timeroffset;
+	cycle_t timestamp;
+};
+#endif
+
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+static DEFINE_PER_CPU(struct hist_data, wakeup_latency_hist);
+static DEFINE_PER_CPU(struct hist_data, wakeup_latency_hist_sharedprio);
+static char *wakeup_latency_hist_dir = "wakeup";
+static char *wakeup_latency_hist_dir_sharedprio = "sharedprio";
+static notrace void probe_wakeup_latency_hist_start(void *v,
+	struct task_struct *p, int success);
+static notrace void probe_wakeup_latency_hist_stop(void *v,
+	struct task_struct *prev, struct task_struct *next);
+static notrace void probe_sched_migrate_task(void *,
+	struct task_struct *task, int cpu);
+static struct enable_data wakeup_latency_enabled_data = {
+	.latency_type = WAKEUP_LATENCY,
+	.enabled = 0,
+};
+static DEFINE_PER_CPU(struct maxlatproc_data, wakeup_maxlatproc);
+static DEFINE_PER_CPU(struct maxlatproc_data, wakeup_maxlatproc_sharedprio);
+static DEFINE_PER_CPU(struct task_struct *, wakeup_task);
+static DEFINE_PER_CPU(int, wakeup_sharedprio);
+static unsigned long wakeup_pid;
+#endif
+
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+static DEFINE_PER_CPU(struct hist_data, missed_timer_offsets);
+static char *missed_timer_offsets_dir = "missed_timer_offsets";
+static notrace void probe_hrtimer_interrupt(void *v, int cpu,
+	long long offset, struct task_struct *curr, struct task_struct *task);
+static struct enable_data missed_timer_offsets_enabled_data = {
+	.latency_type = MISSED_TIMER_OFFSETS,
+	.enabled = 0,
+};
+static DEFINE_PER_CPU(struct maxlatproc_data, missed_timer_offsets_maxlatproc);
+static unsigned long missed_timer_offsets_pid;
+#endif
+
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) && \
+	defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+static DEFINE_PER_CPU(struct hist_data, timerandwakeup_latency_hist);
+static char *timerandwakeup_latency_hist_dir = "timerandwakeup";
+static struct enable_data timerandwakeup_enabled_data = {
+	.latency_type = TIMERANDWAKEUP_LATENCY,
+	.enabled = 0,
+};
+static DEFINE_PER_CPU(struct maxlatproc_data, timerandwakeup_maxlatproc);
+#endif
+
+void notrace latency_hist(int latency_type, int cpu, long latency,
+			  long timeroffset, cycle_t stop,
+			  struct task_struct *p)
+{
+	struct hist_data *my_hist;
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+	defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+	struct maxlatproc_data *mp = NULL;
+#endif
+
+	if (!cpu_possible(cpu) || latency_type < 0 ||
+	    latency_type >= MAX_LATENCY_TYPE)
+		return;
+
+	switch (latency_type) {
+#ifdef CONFIG_INTERRUPT_OFF_HIST
+	case IRQSOFF_LATENCY:
+		my_hist = &per_cpu(irqsoff_hist, cpu);
+		break;
+#endif
+#ifdef CONFIG_PREEMPT_OFF_HIST
+	case PREEMPTOFF_LATENCY:
+		my_hist = &per_cpu(preemptoff_hist, cpu);
+		break;
+#endif
+#if defined(CONFIG_PREEMPT_OFF_HIST) && defined(CONFIG_INTERRUPT_OFF_HIST)
+	case PREEMPTIRQSOFF_LATENCY:
+		my_hist = &per_cpu(preemptirqsoff_hist, cpu);
+		break;
+#endif
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+	case WAKEUP_LATENCY:
+		my_hist = &per_cpu(wakeup_latency_hist, cpu);
+		mp = &per_cpu(wakeup_maxlatproc, cpu);
+		break;
+	case WAKEUP_LATENCY_SHAREDPRIO:
+		my_hist = &per_cpu(wakeup_latency_hist_sharedprio, cpu);
+		mp = &per_cpu(wakeup_maxlatproc_sharedprio, cpu);
+		break;
+#endif
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+	case MISSED_TIMER_OFFSETS:
+		my_hist = &per_cpu(missed_timer_offsets, cpu);
+		mp = &per_cpu(missed_timer_offsets_maxlatproc, cpu);
+		break;
+#endif
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) && \
+	defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+	case TIMERANDWAKEUP_LATENCY:
+		my_hist = &per_cpu(timerandwakeup_latency_hist, cpu);
+		mp = &per_cpu(timerandwakeup_maxlatproc, cpu);
+		break;
+#endif
+
+	default:
+		return;
+	}
+
+	latency += my_hist->offset;
+
+	if (atomic_read(&my_hist->hist_mode) == 0)
+		return;
+
+	if (latency < 0 || latency >= MAX_ENTRY_NUM) {
+		if (latency < 0)
+			my_hist->below_hist_bound_samples++;
+		else
+			my_hist->above_hist_bound_samples++;
+	} else
+		my_hist->hist_array[latency]++;
+
+	if (unlikely(latency > my_hist->max_lat ||
+	    my_hist->min_lat == LONG_MAX)) {
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+	defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+		if (latency_type == WAKEUP_LATENCY ||
+		    latency_type == WAKEUP_LATENCY_SHAREDPRIO ||
+		    latency_type == MISSED_TIMER_OFFSETS ||
+		    latency_type == TIMERANDWAKEUP_LATENCY) {
+			strncpy(mp->comm, p->comm, sizeof(mp->comm));
+			strncpy(mp->current_comm, current->comm,
+			    sizeof(mp->current_comm));
+			mp->pid = task_pid_nr(p);
+			mp->current_pid = task_pid_nr(current);
+			mp->prio = p->prio;
+			mp->current_prio = current->prio;
+			mp->latency = latency;
+			mp->timeroffset = timeroffset;
+			mp->timestamp = stop;
+		}
+#endif
+		my_hist->max_lat = latency;
+	}
+	if (unlikely(latency < my_hist->min_lat))
+		my_hist->min_lat = latency;
+	my_hist->total_samples++;
+	my_hist->accumulate_lat += latency;
+}
+
+static void *l_start(struct seq_file *m, loff_t *pos)
+{
+	loff_t *index_ptr = NULL;
+	loff_t index = *pos;
+	struct hist_data *my_hist = m->private;
+
+	if (index == 0) {
+		char minstr[32], avgstr[32], maxstr[32];
+
+		atomic_dec(&my_hist->hist_mode);
+
+		if (likely(my_hist->total_samples)) {
+			long avg = (long) div64_s64(my_hist->accumulate_lat,
+			    my_hist->total_samples);
+			snprintf(minstr, sizeof(minstr), "%ld",
+			    my_hist->min_lat - my_hist->offset);
+			snprintf(avgstr, sizeof(avgstr), "%ld",
+			    avg - my_hist->offset);
+			snprintf(maxstr, sizeof(maxstr), "%ld",
+			    my_hist->max_lat - my_hist->offset);
+		} else {
+			strcpy(minstr, "<undef>");
+			strcpy(avgstr, minstr);
+			strcpy(maxstr, minstr);
+		}
+
+		seq_printf(m, "#Minimum latency: %s microseconds\n"
+			   "#Average latency: %s microseconds\n"
+			   "#Maximum latency: %s microseconds\n"
+			   "#Total samples: %llu\n"
+			   "#There are %llu samples lower than %ld"
+			   " microseconds.\n"
+			   "#There are %llu samples greater or equal"
+			   " than %ld microseconds.\n"
+			   "#usecs\t%16s\n",
+			   minstr, avgstr, maxstr,
+			   my_hist->total_samples,
+			   my_hist->below_hist_bound_samples,
+			   -my_hist->offset,
+			   my_hist->above_hist_bound_samples,
+			   MAX_ENTRY_NUM - my_hist->offset,
+			   "samples");
+	}
+	if (index < MAX_ENTRY_NUM) {
+		index_ptr = kmalloc(sizeof(loff_t), GFP_KERNEL);
+		if (index_ptr)
+			*index_ptr = index;
+	}
+
+	return index_ptr;
+}
+
+static void *l_next(struct seq_file *m, void *p, loff_t *pos)
+{
+	loff_t *index_ptr = p;
+	struct hist_data *my_hist = m->private;
+
+	if (++*pos >= MAX_ENTRY_NUM) {
+		atomic_inc(&my_hist->hist_mode);
+		return NULL;
+	}
+	*index_ptr = *pos;
+	return index_ptr;
+}
+
+static void l_stop(struct seq_file *m, void *p)
+{
+	kfree(p);
+}
+
+static int l_show(struct seq_file *m, void *p)
+{
+	int index = *(loff_t *) p;
+	struct hist_data *my_hist = m->private;
+
+	seq_printf(m, "%6ld\t%16llu\n", index - my_hist->offset,
+	    my_hist->hist_array[index]);
+	return 0;
+}
+
+static const struct seq_operations latency_hist_seq_op = {
+	.start = l_start,
+	.next  = l_next,
+	.stop  = l_stop,
+	.show  = l_show
+};
+
+static int latency_hist_open(struct inode *inode, struct file *file)
+{
+	int ret;
+
+	ret = seq_open(file, &latency_hist_seq_op);
+	if (!ret) {
+		struct seq_file *seq = file->private_data;
+		seq->private = inode->i_private;
+	}
+	return ret;
+}
+
+static const struct file_operations latency_hist_fops = {
+	.open = latency_hist_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = seq_release,
+};
+
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+	defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+static void clear_maxlatprocdata(struct maxlatproc_data *mp)
+{
+	mp->comm[0] = mp->current_comm[0] = '\0';
+	mp->prio = mp->current_prio = mp->pid = mp->current_pid =
+	    mp->latency = mp->timeroffset = -1;
+	mp->timestamp = 0;
+}
+#endif
+
+static void hist_reset(struct hist_data *hist)
+{
+	atomic_dec(&hist->hist_mode);
+
+	memset(hist->hist_array, 0, sizeof(hist->hist_array));
+	hist->below_hist_bound_samples = 0ULL;
+	hist->above_hist_bound_samples = 0ULL;
+	hist->min_lat = LONG_MAX;
+	hist->max_lat = LONG_MIN;
+	hist->total_samples = 0ULL;
+	hist->accumulate_lat = 0LL;
+
+	atomic_inc(&hist->hist_mode);
+}
+
+static ssize_t
+latency_hist_reset(struct file *file, const char __user *a,
+		   size_t size, loff_t *off)
+{
+	int cpu;
+	struct hist_data *hist = NULL;
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+	defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+	struct maxlatproc_data *mp = NULL;
+#endif
+	off_t latency_type = (off_t) file->private_data;
+
+	for_each_online_cpu(cpu) {
+
+		switch (latency_type) {
+#ifdef CONFIG_PREEMPT_OFF_HIST
+		case PREEMPTOFF_LATENCY:
+			hist = &per_cpu(preemptoff_hist, cpu);
+			break;
+#endif
+#ifdef CONFIG_INTERRUPT_OFF_HIST
+		case IRQSOFF_LATENCY:
+			hist = &per_cpu(irqsoff_hist, cpu);
+			break;
+#endif
+#if defined(CONFIG_INTERRUPT_OFF_HIST) && defined(CONFIG_PREEMPT_OFF_HIST)
+		case PREEMPTIRQSOFF_LATENCY:
+			hist = &per_cpu(preemptirqsoff_hist, cpu);
+			break;
+#endif
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+		case WAKEUP_LATENCY:
+			hist = &per_cpu(wakeup_latency_hist, cpu);
+			mp = &per_cpu(wakeup_maxlatproc, cpu);
+			break;
+		case WAKEUP_LATENCY_SHAREDPRIO:
+			hist = &per_cpu(wakeup_latency_hist_sharedprio, cpu);
+			mp = &per_cpu(wakeup_maxlatproc_sharedprio, cpu);
+			break;
+#endif
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+		case MISSED_TIMER_OFFSETS:
+			hist = &per_cpu(missed_timer_offsets, cpu);
+			mp = &per_cpu(missed_timer_offsets_maxlatproc, cpu);
+			break;
+#endif
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) && \
+	defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+		case TIMERANDWAKEUP_LATENCY:
+			hist = &per_cpu(timerandwakeup_latency_hist, cpu);
+			mp = &per_cpu(timerandwakeup_maxlatproc, cpu);
+			break;
+#endif
+		}
+
+		hist_reset(hist);
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+	defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+		if (latency_type == WAKEUP_LATENCY ||
+		    latency_type == WAKEUP_LATENCY_SHAREDPRIO ||
+		    latency_type == MISSED_TIMER_OFFSETS ||
+		    latency_type == TIMERANDWAKEUP_LATENCY)
+			clear_maxlatprocdata(mp);
+#endif
+	}
+
+	return size;
+}
+
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+	defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+static ssize_t
+show_pid(struct file *file, char __user *ubuf, size_t cnt, loff_t *ppos)
+{
+	char buf[64];
+	int r;
+	unsigned long *this_pid = file->private_data;
+
+	r = snprintf(buf, sizeof(buf), "%lu\n", *this_pid);
+	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+}
+
+static ssize_t do_pid(struct file *file, const char __user *ubuf,
+		      size_t cnt, loff_t *ppos)
+{
+	char buf[64];
+	unsigned long pid;
+	unsigned long *this_pid = file->private_data;
+
+	if (cnt >= sizeof(buf))
+		return -EINVAL;
+
+	if (copy_from_user(&buf, ubuf, cnt))
+		return -EFAULT;
+
+	buf[cnt] = '\0';
+
+	if (kstrtoul(buf, 10, &pid))
+		return -EINVAL;
+
+	*this_pid = pid;
+
+	return cnt;
+}
+#endif
+
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+	defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+static ssize_t
+show_maxlatproc(struct file *file, char __user *ubuf, size_t cnt, loff_t *ppos)
+{
+	int r;
+	struct maxlatproc_data *mp = file->private_data;
+	int strmaxlen = (TASK_COMM_LEN * 2) + (8 * 8);
+	unsigned long long t;
+	unsigned long usecs, secs;
+	char *buf;
+
+	if (mp->pid == -1 || mp->current_pid == -1) {
+		buf = "(none)\n";
+		return simple_read_from_buffer(ubuf, cnt, ppos, buf,
+		    strlen(buf));
+	}
+
+	buf = kmalloc(strmaxlen, GFP_KERNEL);
+	if (buf == NULL)
+		return -ENOMEM;
+
+	t = ns2usecs(mp->timestamp);
+	usecs = do_div(t, USEC_PER_SEC);
+	secs = (unsigned long) t;
+	r = snprintf(buf, strmaxlen,
+	    "%d %d %ld (%ld) %s <- %d %d %s %lu.%06lu\n", mp->pid,
+	    MAX_RT_PRIO-1 - mp->prio, mp->latency, mp->timeroffset, mp->comm,
+	    mp->current_pid, MAX_RT_PRIO-1 - mp->current_prio, mp->current_comm,
+	    secs, usecs);
+	r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+	kfree(buf);
+	return r;
+}
+#endif
+
+static ssize_t
+show_enable(struct file *file, char __user *ubuf, size_t cnt, loff_t *ppos)
+{
+	char buf[64];
+	struct enable_data *ed = file->private_data;
+	int r;
+
+	r = snprintf(buf, sizeof(buf), "%d\n", ed->enabled);
+	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+}
+
+static ssize_t
+do_enable(struct file *file, const char __user *ubuf, size_t cnt, loff_t *ppos)
+{
+	char buf[64];
+	long enable;
+	struct enable_data *ed = file->private_data;
+
+	if (cnt >= sizeof(buf))
+		return -EINVAL;
+
+	if (copy_from_user(&buf, ubuf, cnt))
+		return -EFAULT;
+
+	buf[cnt] = 0;
+
+	if (kstrtoul(buf, 10, &enable))
+		return -EINVAL;
+
+	if ((enable && ed->enabled) || (!enable && !ed->enabled))
+		return cnt;
+
+	if (enable) {
+		int ret;
+
+		switch (ed->latency_type) {
+#if defined(CONFIG_INTERRUPT_OFF_HIST) || defined(CONFIG_PREEMPT_OFF_HIST)
+		case PREEMPTIRQSOFF_LATENCY:
+			ret = register_trace_preemptirqsoff_hist(
+			    probe_preemptirqsoff_hist, NULL);
+			if (ret) {
+				pr_info("wakeup trace: Couldn't assign "
+				    "probe_preemptirqsoff_hist "
+				    "to trace_preemptirqsoff_hist\n");
+				return ret;
+			}
+			break;
+#endif
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+		case WAKEUP_LATENCY:
+			ret = register_trace_sched_wakeup(
+			    probe_wakeup_latency_hist_start, NULL);
+			if (ret) {
+				pr_info("wakeup trace: Couldn't assign "
+				    "probe_wakeup_latency_hist_start "
+				    "to trace_sched_wakeup\n");
+				return ret;
+			}
+			ret = register_trace_sched_wakeup_new(
+			    probe_wakeup_latency_hist_start, NULL);
+			if (ret) {
+				pr_info("wakeup trace: Couldn't assign "
+				    "probe_wakeup_latency_hist_start "
+				    "to trace_sched_wakeup_new\n");
+				unregister_trace_sched_wakeup(
+				    probe_wakeup_latency_hist_start, NULL);
+				return ret;
+			}
+			ret = register_trace_sched_switch(
+			    probe_wakeup_latency_hist_stop, NULL);
+			if (ret) {
+				pr_info("wakeup trace: Couldn't assign "
+				    "probe_wakeup_latency_hist_stop "
+				    "to trace_sched_switch\n");
+				unregister_trace_sched_wakeup(
+				    probe_wakeup_latency_hist_start, NULL);
+				unregister_trace_sched_wakeup_new(
+				    probe_wakeup_latency_hist_start, NULL);
+				return ret;
+			}
+			ret = register_trace_sched_migrate_task(
+			    probe_sched_migrate_task, NULL);
+			if (ret) {
+				pr_info("wakeup trace: Couldn't assign "
+				    "probe_sched_migrate_task "
+				    "to trace_sched_migrate_task\n");
+				unregister_trace_sched_wakeup(
+				    probe_wakeup_latency_hist_start, NULL);
+				unregister_trace_sched_wakeup_new(
+				    probe_wakeup_latency_hist_start, NULL);
+				unregister_trace_sched_switch(
+				    probe_wakeup_latency_hist_stop, NULL);
+				return ret;
+			}
+			break;
+#endif
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+		case MISSED_TIMER_OFFSETS:
+			ret = register_trace_hrtimer_interrupt(
+			    probe_hrtimer_interrupt, NULL);
+			if (ret) {
+				pr_info("wakeup trace: Couldn't assign "
+				    "probe_hrtimer_interrupt "
+				    "to trace_hrtimer_interrupt\n");
+				return ret;
+			}
+			break;
+#endif
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) && \
+	defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+		case TIMERANDWAKEUP_LATENCY:
+			if (!wakeup_latency_enabled_data.enabled ||
+			    !missed_timer_offsets_enabled_data.enabled)
+				return -EINVAL;
+			break;
+#endif
+		default:
+			break;
+		}
+	} else {
+		switch (ed->latency_type) {
+#if defined(CONFIG_INTERRUPT_OFF_HIST) || defined(CONFIG_PREEMPT_OFF_HIST)
+		case PREEMPTIRQSOFF_LATENCY:
+			{
+				int cpu;
+
+				unregister_trace_preemptirqsoff_hist(
+				    probe_preemptirqsoff_hist, NULL);
+				for_each_online_cpu(cpu) {
+#ifdef CONFIG_INTERRUPT_OFF_HIST
+					per_cpu(hist_irqsoff_counting,
+					    cpu) = 0;
+#endif
+#ifdef CONFIG_PREEMPT_OFF_HIST
+					per_cpu(hist_preemptoff_counting,
+					    cpu) = 0;
+#endif
+#if defined(CONFIG_INTERRUPT_OFF_HIST) && defined(CONFIG_PREEMPT_OFF_HIST)
+					per_cpu(hist_preemptirqsoff_counting,
+					    cpu) = 0;
+#endif
+				}
+			}
+			break;
+#endif
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+		case WAKEUP_LATENCY:
+			{
+				int cpu;
+
+				unregister_trace_sched_wakeup(
+				    probe_wakeup_latency_hist_start, NULL);
+				unregister_trace_sched_wakeup_new(
+				    probe_wakeup_latency_hist_start, NULL);
+				unregister_trace_sched_switch(
+				    probe_wakeup_latency_hist_stop, NULL);
+				unregister_trace_sched_migrate_task(
+				    probe_sched_migrate_task, NULL);
+
+				for_each_online_cpu(cpu) {
+					per_cpu(wakeup_task, cpu) = NULL;
+					per_cpu(wakeup_sharedprio, cpu) = 0;
+				}
+			}
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+			timerandwakeup_enabled_data.enabled = 0;
+#endif
+			break;
+#endif
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+		case MISSED_TIMER_OFFSETS:
+			unregister_trace_hrtimer_interrupt(
+			    probe_hrtimer_interrupt, NULL);
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+			timerandwakeup_enabled_data.enabled = 0;
+#endif
+			break;
+#endif
+		default:
+			break;
+		}
+	}
+	ed->enabled = enable;
+	return cnt;
+}
+
+static const struct file_operations latency_hist_reset_fops = {
+	.open = tracing_open_generic,
+	.write = latency_hist_reset,
+};
+
+static const struct file_operations enable_fops = {
+	.open = tracing_open_generic,
+	.read = show_enable,
+	.write = do_enable,
+};
+
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+	defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+static const struct file_operations pid_fops = {
+	.open = tracing_open_generic,
+	.read = show_pid,
+	.write = do_pid,
+};
+
+static const struct file_operations maxlatproc_fops = {
+	.open = tracing_open_generic,
+	.read = show_maxlatproc,
+};
+#endif
+
+#if defined(CONFIG_INTERRUPT_OFF_HIST) || defined(CONFIG_PREEMPT_OFF_HIST)
+static notrace void probe_preemptirqsoff_hist(void *v, int reason,
+	int starthist)
+{
+	int cpu = raw_smp_processor_id();
+	int time_set = 0;
+
+	if (starthist) {
+		cycle_t uninitialized_var(start);
+
+		if (!preempt_count() && !irqs_disabled())
+			return;
+
+#ifdef CONFIG_INTERRUPT_OFF_HIST
+		if ((reason == IRQS_OFF || reason == TRACE_START) &&
+		    !per_cpu(hist_irqsoff_counting, cpu)) {
+			per_cpu(hist_irqsoff_counting, cpu) = 1;
+			start = ftrace_now(cpu);
+			time_set++;
+			per_cpu(hist_irqsoff_start, cpu) = start;
+		}
+#endif
+
+#ifdef CONFIG_PREEMPT_OFF_HIST
+		if ((reason == PREEMPT_OFF || reason == TRACE_START) &&
+		    !per_cpu(hist_preemptoff_counting, cpu)) {
+			per_cpu(hist_preemptoff_counting, cpu) = 1;
+			if (!(time_set++))
+				start = ftrace_now(cpu);
+			per_cpu(hist_preemptoff_start, cpu) = start;
+		}
+#endif
+
+#if defined(CONFIG_INTERRUPT_OFF_HIST) && defined(CONFIG_PREEMPT_OFF_HIST)
+		if (per_cpu(hist_irqsoff_counting, cpu) &&
+		    per_cpu(hist_preemptoff_counting, cpu) &&
+		    !per_cpu(hist_preemptirqsoff_counting, cpu)) {
+			per_cpu(hist_preemptirqsoff_counting, cpu) = 1;
+			if (!time_set)
+				start = ftrace_now(cpu);
+			per_cpu(hist_preemptirqsoff_start, cpu) = start;
+		}
+#endif
+	} else {
+		cycle_t uninitialized_var(stop);
+
+#ifdef CONFIG_INTERRUPT_OFF_HIST
+		if ((reason == IRQS_ON || reason == TRACE_STOP) &&
+		    per_cpu(hist_irqsoff_counting, cpu)) {
+			cycle_t start = per_cpu(hist_irqsoff_start, cpu);
+
+			stop = ftrace_now(cpu);
+			time_set++;
+			if (start) {
+				long latency = ((long) (stop - start)) /
+				    NSECS_PER_USECS;
+
+				latency_hist(IRQSOFF_LATENCY, cpu, latency, 0,
+				    stop, NULL);
+			}
+			per_cpu(hist_irqsoff_counting, cpu) = 0;
+		}
+#endif
+
+#ifdef CONFIG_PREEMPT_OFF_HIST
+		if ((reason == PREEMPT_ON || reason == TRACE_STOP) &&
+		    per_cpu(hist_preemptoff_counting, cpu)) {
+			cycle_t start = per_cpu(hist_preemptoff_start, cpu);
+
+			if (!(time_set++))
+				stop = ftrace_now(cpu);
+			if (start) {
+				long latency = ((long) (stop - start)) /
+				    NSECS_PER_USECS;
+
+				latency_hist(PREEMPTOFF_LATENCY, cpu, latency,
+				    0, stop, NULL);
+			}
+			per_cpu(hist_preemptoff_counting, cpu) = 0;
+		}
+#endif
+
+#if defined(CONFIG_INTERRUPT_OFF_HIST) && defined(CONFIG_PREEMPT_OFF_HIST)
+		if ((!per_cpu(hist_irqsoff_counting, cpu) ||
+		     !per_cpu(hist_preemptoff_counting, cpu)) &&
+		   per_cpu(hist_preemptirqsoff_counting, cpu)) {
+			cycle_t start = per_cpu(hist_preemptirqsoff_start, cpu);
+
+			if (!time_set)
+				stop = ftrace_now(cpu);
+			if (start) {
+				long latency = ((long) (stop - start)) /
+				    NSECS_PER_USECS;
+
+				latency_hist(PREEMPTIRQSOFF_LATENCY, cpu,
+				    latency, 0, stop, NULL);
+			}
+			per_cpu(hist_preemptirqsoff_counting, cpu) = 0;
+		}
+#endif
+	}
+}
+#endif
+
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+static DEFINE_RAW_SPINLOCK(wakeup_lock);
+static notrace void probe_sched_migrate_task(void *v, struct task_struct *task,
+	int cpu)
+{
+	int old_cpu = task_cpu(task);
+
+	if (cpu != old_cpu) {
+		unsigned long flags;
+		struct task_struct *cpu_wakeup_task;
+
+		raw_spin_lock_irqsave(&wakeup_lock, flags);
+
+		cpu_wakeup_task = per_cpu(wakeup_task, old_cpu);
+		if (task == cpu_wakeup_task) {
+			put_task_struct(cpu_wakeup_task);
+			per_cpu(wakeup_task, old_cpu) = NULL;
+			cpu_wakeup_task = per_cpu(wakeup_task, cpu) = task;
+			get_task_struct(cpu_wakeup_task);
+		}
+
+		raw_spin_unlock_irqrestore(&wakeup_lock, flags);
+	}
+}
+
+static notrace void probe_wakeup_latency_hist_start(void *v,
+	struct task_struct *p, int success)
+{
+	unsigned long flags;
+	struct task_struct *curr = current;
+	int cpu = task_cpu(p);
+	struct task_struct *cpu_wakeup_task;
+
+	raw_spin_lock_irqsave(&wakeup_lock, flags);
+
+	cpu_wakeup_task = per_cpu(wakeup_task, cpu);
+
+	if (wakeup_pid) {
+		if ((cpu_wakeup_task && p->prio == cpu_wakeup_task->prio) ||
+		    p->prio == curr->prio)
+			per_cpu(wakeup_sharedprio, cpu) = 1;
+		if (likely(wakeup_pid != task_pid_nr(p)))
+			goto out;
+	} else {
+		if (likely(!rt_task(p)) ||
+		    (cpu_wakeup_task && p->prio > cpu_wakeup_task->prio) ||
+		    p->prio > curr->prio)
+			goto out;
+		if ((cpu_wakeup_task && p->prio == cpu_wakeup_task->prio) ||
+		    p->prio == curr->prio)
+			per_cpu(wakeup_sharedprio, cpu) = 1;
+	}
+
+	if (cpu_wakeup_task)
+		put_task_struct(cpu_wakeup_task);
+	cpu_wakeup_task = per_cpu(wakeup_task, cpu) = p;
+	get_task_struct(cpu_wakeup_task);
+	cpu_wakeup_task->preempt_timestamp_hist =
+		ftrace_now(raw_smp_processor_id());
+out:
+	raw_spin_unlock_irqrestore(&wakeup_lock, flags);
+}
+
+static notrace void probe_wakeup_latency_hist_stop(void *v,
+	struct task_struct *prev, struct task_struct *next)
+{
+	unsigned long flags;
+	int cpu = task_cpu(next);
+	long latency;
+	cycle_t stop;
+	struct task_struct *cpu_wakeup_task;
+
+	raw_spin_lock_irqsave(&wakeup_lock, flags);
+
+	cpu_wakeup_task = per_cpu(wakeup_task, cpu);
+
+	if (cpu_wakeup_task == NULL)
+		goto out;
+
+	/* Already running? */
+	if (unlikely(current == cpu_wakeup_task))
+		goto out_reset;
+
+	if (next != cpu_wakeup_task) {
+		if (next->prio < cpu_wakeup_task->prio)
+			goto out_reset;
+
+		if (next->prio == cpu_wakeup_task->prio)
+			per_cpu(wakeup_sharedprio, cpu) = 1;
+
+		goto out;
+	}
+
+	if (current->prio == cpu_wakeup_task->prio)
+		per_cpu(wakeup_sharedprio, cpu) = 1;
+
+	/*
+	 * The task we are waiting for is about to be switched to.
+	 * Calculate latency and store it in histogram.
+	 */
+	stop = ftrace_now(raw_smp_processor_id());
+
+	latency = ((long) (stop - next->preempt_timestamp_hist)) /
+	    NSECS_PER_USECS;
+
+	if (per_cpu(wakeup_sharedprio, cpu)) {
+		latency_hist(WAKEUP_LATENCY_SHAREDPRIO, cpu, latency, 0, stop,
+		    next);
+		per_cpu(wakeup_sharedprio, cpu) = 0;
+	} else {
+		latency_hist(WAKEUP_LATENCY, cpu, latency, 0, stop, next);
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+		if (timerandwakeup_enabled_data.enabled) {
+			latency_hist(TIMERANDWAKEUP_LATENCY, cpu,
+			    next->timer_offset + latency, next->timer_offset,
+			    stop, next);
+		}
+#endif
+	}
+
+out_reset:
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+	next->timer_offset = 0;
+#endif
+	put_task_struct(cpu_wakeup_task);
+	per_cpu(wakeup_task, cpu) = NULL;
+out:
+	raw_spin_unlock_irqrestore(&wakeup_lock, flags);
+}
+#endif
+
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+static notrace void probe_hrtimer_interrupt(void *v, int cpu,
+	long long latency_ns, struct task_struct *curr,
+	struct task_struct *task)
+{
+	if (latency_ns <= 0 && task != NULL && rt_task(task) &&
+	    (task->prio < curr->prio ||
+	    (task->prio == curr->prio &&
+	    !cpumask_test_cpu(cpu, &task->cpus_allowed)))) {
+		long latency;
+		cycle_t now;
+
+		if (missed_timer_offsets_pid) {
+			if (likely(missed_timer_offsets_pid !=
+			    task_pid_nr(task)))
+				return;
+		}
+
+		now = ftrace_now(cpu);
+		latency = (long) div_s64(-latency_ns, NSECS_PER_USECS);
+		latency_hist(MISSED_TIMER_OFFSETS, cpu, latency, latency, now,
+		    task);
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+		task->timer_offset = latency;
+#endif
+	}
+}
+#endif
+
+static __init int latency_hist_init(void)
+{
+	struct dentry *latency_hist_root = NULL;
+	struct dentry *dentry;
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+	struct dentry *dentry_sharedprio;
+#endif
+	struct dentry *entry;
+	struct dentry *enable_root;
+	int i = 0;
+	struct hist_data *my_hist;
+	char name[64];
+	char *cpufmt = "CPU%d";
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) || \
+	defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+	char *cpufmt_maxlatproc = "max_latency-CPU%d";
+	struct maxlatproc_data *mp = NULL;
+#endif
+
+	dentry = tracing_init_dentry();
+	latency_hist_root = debugfs_create_dir(latency_hist_dir_root, dentry);
+	enable_root = debugfs_create_dir("enable", latency_hist_root);
+
+#ifdef CONFIG_INTERRUPT_OFF_HIST
+	dentry = debugfs_create_dir(irqsoff_hist_dir, latency_hist_root);
+	for_each_possible_cpu(i) {
+		sprintf(name, cpufmt, i);
+		entry = debugfs_create_file(name, 0444, dentry,
+		    &per_cpu(irqsoff_hist, i), &latency_hist_fops);
+		my_hist = &per_cpu(irqsoff_hist, i);
+		atomic_set(&my_hist->hist_mode, 1);
+		my_hist->min_lat = LONG_MAX;
+	}
+	entry = debugfs_create_file("reset", 0644, dentry,
+	    (void *)IRQSOFF_LATENCY, &latency_hist_reset_fops);
+#endif
+
+#ifdef CONFIG_PREEMPT_OFF_HIST
+	dentry = debugfs_create_dir(preemptoff_hist_dir,
+	    latency_hist_root);
+	for_each_possible_cpu(i) {
+		sprintf(name, cpufmt, i);
+		entry = debugfs_create_file(name, 0444, dentry,
+		    &per_cpu(preemptoff_hist, i), &latency_hist_fops);
+		my_hist = &per_cpu(preemptoff_hist, i);
+		atomic_set(&my_hist->hist_mode, 1);
+		my_hist->min_lat = LONG_MAX;
+	}
+	entry = debugfs_create_file("reset", 0644, dentry,
+	    (void *)PREEMPTOFF_LATENCY, &latency_hist_reset_fops);
+#endif
+
+#if defined(CONFIG_INTERRUPT_OFF_HIST) && defined(CONFIG_PREEMPT_OFF_HIST)
+	dentry = debugfs_create_dir(preemptirqsoff_hist_dir,
+	    latency_hist_root);
+	for_each_possible_cpu(i) {
+		sprintf(name, cpufmt, i);
+		entry = debugfs_create_file(name, 0444, dentry,
+		    &per_cpu(preemptirqsoff_hist, i), &latency_hist_fops);
+		my_hist = &per_cpu(preemptirqsoff_hist, i);
+		atomic_set(&my_hist->hist_mode, 1);
+		my_hist->min_lat = LONG_MAX;
+	}
+	entry = debugfs_create_file("reset", 0644, dentry,
+	    (void *)PREEMPTIRQSOFF_LATENCY, &latency_hist_reset_fops);
+#endif
+
+#if defined(CONFIG_INTERRUPT_OFF_HIST) || defined(CONFIG_PREEMPT_OFF_HIST)
+	entry = debugfs_create_file("preemptirqsoff", 0644,
+	    enable_root, (void *)&preemptirqsoff_enabled_data,
+	    &enable_fops);
+#endif
+
+#ifdef CONFIG_WAKEUP_LATENCY_HIST
+	dentry = debugfs_create_dir(wakeup_latency_hist_dir,
+	    latency_hist_root);
+	dentry_sharedprio = debugfs_create_dir(
+	    wakeup_latency_hist_dir_sharedprio, dentry);
+	for_each_possible_cpu(i) {
+		sprintf(name, cpufmt, i);
+
+		entry = debugfs_create_file(name, 0444, dentry,
+		    &per_cpu(wakeup_latency_hist, i),
+		    &latency_hist_fops);
+		my_hist = &per_cpu(wakeup_latency_hist, i);
+		atomic_set(&my_hist->hist_mode, 1);
+		my_hist->min_lat = LONG_MAX;
+
+		entry = debugfs_create_file(name, 0444, dentry_sharedprio,
+		    &per_cpu(wakeup_latency_hist_sharedprio, i),
+		    &latency_hist_fops);
+		my_hist = &per_cpu(wakeup_latency_hist_sharedprio, i);
+		atomic_set(&my_hist->hist_mode, 1);
+		my_hist->min_lat = LONG_MAX;
+
+		sprintf(name, cpufmt_maxlatproc, i);
+
+		mp = &per_cpu(wakeup_maxlatproc, i);
+		entry = debugfs_create_file(name, 0444, dentry, mp,
+		    &maxlatproc_fops);
+		clear_maxlatprocdata(mp);
+
+		mp = &per_cpu(wakeup_maxlatproc_sharedprio, i);
+		entry = debugfs_create_file(name, 0444, dentry_sharedprio, mp,
+		    &maxlatproc_fops);
+		clear_maxlatprocdata(mp);
+	}
+	entry = debugfs_create_file("pid", 0644, dentry,
+	    (void *)&wakeup_pid, &pid_fops);
+	entry = debugfs_create_file("reset", 0644, dentry,
+	    (void *)WAKEUP_LATENCY, &latency_hist_reset_fops);
+	entry = debugfs_create_file("reset", 0644, dentry_sharedprio,
+	    (void *)WAKEUP_LATENCY_SHAREDPRIO, &latency_hist_reset_fops);
+	entry = debugfs_create_file("wakeup", 0644,
+	    enable_root, (void *)&wakeup_latency_enabled_data,
+	    &enable_fops);
+#endif
+
+#ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
+	dentry = debugfs_create_dir(missed_timer_offsets_dir,
+	    latency_hist_root);
+	for_each_possible_cpu(i) {
+		sprintf(name, cpufmt, i);
+		entry = debugfs_create_file(name, 0444, dentry,
+		    &per_cpu(missed_timer_offsets, i), &latency_hist_fops);
+		my_hist = &per_cpu(missed_timer_offsets, i);
+		atomic_set(&my_hist->hist_mode, 1);
+		my_hist->min_lat = LONG_MAX;
+
+		sprintf(name, cpufmt_maxlatproc, i);
+		mp = &per_cpu(missed_timer_offsets_maxlatproc, i);
+		entry = debugfs_create_file(name, 0444, dentry, mp,
+		    &maxlatproc_fops);
+		clear_maxlatprocdata(mp);
+	}
+	entry = debugfs_create_file("pid", 0644, dentry,
+	    (void *)&missed_timer_offsets_pid, &pid_fops);
+	entry = debugfs_create_file("reset", 0644, dentry,
+	    (void *)MISSED_TIMER_OFFSETS, &latency_hist_reset_fops);
+	entry = debugfs_create_file("missed_timer_offsets", 0644,
+	    enable_root, (void *)&missed_timer_offsets_enabled_data,
+	    &enable_fops);
+#endif
+
+#if defined(CONFIG_WAKEUP_LATENCY_HIST) && \
+	defined(CONFIG_MISSED_TIMER_OFFSETS_HIST)
+	dentry = debugfs_create_dir(timerandwakeup_latency_hist_dir,
+	    latency_hist_root);
+	for_each_possible_cpu(i) {
+		sprintf(name, cpufmt, i);
+		entry = debugfs_create_file(name, 0444, dentry,
+		    &per_cpu(timerandwakeup_latency_hist, i),
+		    &latency_hist_fops);
+		my_hist = &per_cpu(timerandwakeup_latency_hist, i);
+		atomic_set(&my_hist->hist_mode, 1);
+		my_hist->min_lat = LONG_MAX;
+
+		sprintf(name, cpufmt_maxlatproc, i);
+		mp = &per_cpu(timerandwakeup_maxlatproc, i);
+		entry = debugfs_create_file(name, 0444, dentry, mp,
+		    &maxlatproc_fops);
+		clear_maxlatprocdata(mp);
+	}
+	entry = debugfs_create_file("reset", 0644, dentry,
+	    (void *)TIMERANDWAKEUP_LATENCY, &latency_hist_reset_fops);
+	entry = debugfs_create_file("timerandwakeup", 0644,
+	    enable_root, (void *)&timerandwakeup_enabled_data,
+	    &enable_fops);
+#endif
+	return 0;
+}
+
+device_initcall(latency_hist_init);
diff -Nur linux-3.18.12.orig/kernel/trace/Makefile linux-3.18.12/kernel/trace/Makefile
--- linux-3.18.12.orig/kernel/trace/Makefile	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/trace/Makefile	2015-04-26 13:32:22.455684003 -0500
@@ -36,6 +36,10 @@
 obj-$(CONFIG_IRQSOFF_TRACER) += trace_irqsoff.o
 obj-$(CONFIG_PREEMPT_TRACER) += trace_irqsoff.o
 obj-$(CONFIG_SCHED_TRACER) += trace_sched_wakeup.o
+obj-$(CONFIG_INTERRUPT_OFF_HIST) += latency_hist.o
+obj-$(CONFIG_PREEMPT_OFF_HIST) += latency_hist.o
+obj-$(CONFIG_WAKEUP_LATENCY_HIST) += latency_hist.o
+obj-$(CONFIG_MISSED_TIMER_OFFSETS_HIST) += latency_hist.o
 obj-$(CONFIG_NOP_TRACER) += trace_nop.o
 obj-$(CONFIG_STACK_TRACER) += trace_stack.o
 obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o
diff -Nur linux-3.18.12.orig/kernel/trace/trace.c linux-3.18.12/kernel/trace/trace.c
--- linux-3.18.12.orig/kernel/trace/trace.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/trace/trace.c	2015-04-26 13:32:22.455684003 -0500
@@ -1579,6 +1579,7 @@
 	struct task_struct *tsk = current;
 
 	entry->preempt_count		= pc & 0xff;
+	entry->preempt_lazy_count	= preempt_lazy_count();
 	entry->pid			= (tsk) ? tsk->pid : 0;
 	entry->flags =
 #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
@@ -1588,8 +1589,11 @@
 #endif
 		((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
 		((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
-		(tif_need_resched() ? TRACE_FLAG_NEED_RESCHED : 0) |
+		(tif_need_resched_now() ? TRACE_FLAG_NEED_RESCHED : 0) |
+		(need_resched_lazy() ? TRACE_FLAG_NEED_RESCHED_LAZY : 0) |
 		(test_preempt_need_resched() ? TRACE_FLAG_PREEMPT_RESCHED : 0);
+
+	entry->migrate_disable = (tsk) ? __migrate_disabled(tsk) & 0xFF : 0;
 }
 EXPORT_SYMBOL_GPL(tracing_generic_entry_update);
 
@@ -2509,14 +2513,17 @@
 
 static void print_lat_help_header(struct seq_file *m)
 {
-	seq_puts(m, "#                  _------=> CPU#            \n");
-	seq_puts(m, "#                 / _-----=> irqs-off        \n");
-	seq_puts(m, "#                | / _----=> need-resched    \n");
-	seq_puts(m, "#                || / _---=> hardirq/softirq \n");
-	seq_puts(m, "#                ||| / _--=> preempt-depth   \n");
-	seq_puts(m, "#                |||| /     delay             \n");
-	seq_puts(m, "#  cmd     pid   ||||| time  |   caller      \n");
-	seq_puts(m, "#     \\   /      |||||  \\    |   /           \n");
+	seq_puts(m, "#                   _--------=> CPU#              \n");
+	seq_puts(m, "#                  / _-------=> irqs-off          \n");
+	seq_puts(m, "#                 | / _------=> need-resched      \n");
+	seq_puts(m, "#                 || / _-----=> need-resched_lazy \n");
+	seq_puts(m, "#                 ||| / _----=> hardirq/softirq   \n");
+	seq_puts(m, "#                 |||| / _---=> preempt-depth     \n");
+	seq_puts(m, "#                 ||||| / _--=> preempt-lazy-depth\n");
+	seq_puts(m, "#                 |||||| / _-=> migrate-disable   \n");
+	seq_puts(m, "#                 ||||||| /     delay             \n");
+	seq_puts(m, "#  cmd     pid    |||||||| time  |   caller       \n");
+	seq_puts(m, "#     \\   /      ||||||||  \\   |   /            \n");
 }
 
 static void print_event_info(struct trace_buffer *buf, struct seq_file *m)
@@ -2540,13 +2547,16 @@
 static void print_func_help_header_irq(struct trace_buffer *buf, struct seq_file *m)
 {
 	print_event_info(buf, m);
-	seq_puts(m, "#                              _-----=> irqs-off\n");
-	seq_puts(m, "#                             / _----=> need-resched\n");
-	seq_puts(m, "#                            | / _---=> hardirq/softirq\n");
-	seq_puts(m, "#                            || / _--=> preempt-depth\n");
-	seq_puts(m, "#                            ||| /     delay\n");
-	seq_puts(m, "#           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION\n");
-	seq_puts(m, "#              | |       |   ||||       |         |\n");
+	seq_puts(m, "#                              _-------=> irqs-off          \n");
+	seq_puts(m, "#                            /  _------=> need-resched      \n");
+	seq_puts(m, "#                            |/  _-----=> need-resched_lazy \n");
+	seq_puts(m, "#                            ||/  _----=> hardirq/softirq   \n");
+	seq_puts(m, "#                            |||/  _---=> preempt-depth     \n");
+	seq_puts(m, "#                            ||||/  _--=> preempt-lazy-depth\n");
+	seq_puts(m, "#                            ||||| / _-=> migrate-disable   \n");
+	seq_puts(m, "#                            |||||| /     delay\n");
+	seq_puts(m, "#           TASK-PID   CPU#  ||||||  TIMESTAMP  FUNCTION\n");
+	seq_puts(m, "#              | |       |   ||||||     |         |\n");
 }
 
 void
diff -Nur linux-3.18.12.orig/kernel/trace/trace_events.c linux-3.18.12/kernel/trace/trace_events.c
--- linux-3.18.12.orig/kernel/trace/trace_events.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/trace/trace_events.c	2015-04-26 13:32:22.455684003 -0500
@@ -162,6 +162,8 @@
 	__common_field(unsigned char, flags);
 	__common_field(unsigned char, preempt_count);
 	__common_field(int, pid);
+	__common_field(unsigned short, migrate_disable);
+	__common_field(unsigned short, padding);
 
 	return ret;
 }
diff -Nur linux-3.18.12.orig/kernel/trace/trace.h linux-3.18.12/kernel/trace/trace.h
--- linux-3.18.12.orig/kernel/trace/trace.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/trace/trace.h	2015-04-26 13:32:22.455684003 -0500
@@ -119,6 +119,7 @@
  *  NEED_RESCHED	- reschedule is requested
  *  HARDIRQ		- inside an interrupt handler
  *  SOFTIRQ		- inside a softirq handler
+ *  NEED_RESCHED_LAZY	- lazy reschedule is requested
  */
 enum trace_flag_type {
 	TRACE_FLAG_IRQS_OFF		= 0x01,
@@ -127,6 +128,7 @@
 	TRACE_FLAG_HARDIRQ		= 0x08,
 	TRACE_FLAG_SOFTIRQ		= 0x10,
 	TRACE_FLAG_PREEMPT_RESCHED	= 0x20,
+	TRACE_FLAG_NEED_RESCHED_LAZY    = 0x40,
 };
 
 #define TRACE_BUF_SIZE		1024
diff -Nur linux-3.18.12.orig/kernel/trace/trace_irqsoff.c linux-3.18.12/kernel/trace/trace_irqsoff.c
--- linux-3.18.12.orig/kernel/trace/trace_irqsoff.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/trace/trace_irqsoff.c	2015-04-26 13:32:22.455684003 -0500
@@ -17,6 +17,7 @@
 #include <linux/fs.h>
 
 #include "trace.h"
+#include <trace/events/hist.h>
 
 static struct trace_array		*irqsoff_trace __read_mostly;
 static int				tracer_enabled __read_mostly;
@@ -435,11 +436,13 @@
 {
 	if (preempt_trace() || irq_trace())
 		start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
+	trace_preemptirqsoff_hist(TRACE_START, 1);
 }
 EXPORT_SYMBOL_GPL(start_critical_timings);
 
 void stop_critical_timings(void)
 {
+	trace_preemptirqsoff_hist(TRACE_STOP, 0);
 	if (preempt_trace() || irq_trace())
 		stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
 }
@@ -449,6 +452,7 @@
 #ifdef CONFIG_PROVE_LOCKING
 void time_hardirqs_on(unsigned long a0, unsigned long a1)
 {
+	trace_preemptirqsoff_hist(IRQS_ON, 0);
 	if (!preempt_trace() && irq_trace())
 		stop_critical_timing(a0, a1);
 }
@@ -457,6 +461,7 @@
 {
 	if (!preempt_trace() && irq_trace())
 		start_critical_timing(a0, a1);
+	trace_preemptirqsoff_hist(IRQS_OFF, 1);
 }
 
 #else /* !CONFIG_PROVE_LOCKING */
@@ -482,6 +487,7 @@
  */
 void trace_hardirqs_on(void)
 {
+	trace_preemptirqsoff_hist(IRQS_ON, 0);
 	if (!preempt_trace() && irq_trace())
 		stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
 }
@@ -491,11 +497,13 @@
 {
 	if (!preempt_trace() && irq_trace())
 		start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
+	trace_preemptirqsoff_hist(IRQS_OFF, 1);
 }
 EXPORT_SYMBOL(trace_hardirqs_off);
 
 __visible void trace_hardirqs_on_caller(unsigned long caller_addr)
 {
+	trace_preemptirqsoff_hist(IRQS_ON, 0);
 	if (!preempt_trace() && irq_trace())
 		stop_critical_timing(CALLER_ADDR0, caller_addr);
 }
@@ -505,6 +513,7 @@
 {
 	if (!preempt_trace() && irq_trace())
 		start_critical_timing(CALLER_ADDR0, caller_addr);
+	trace_preemptirqsoff_hist(IRQS_OFF, 1);
 }
 EXPORT_SYMBOL(trace_hardirqs_off_caller);
 
@@ -514,12 +523,14 @@
 #ifdef CONFIG_PREEMPT_TRACER
 void trace_preempt_on(unsigned long a0, unsigned long a1)
 {
+	trace_preemptirqsoff_hist(PREEMPT_ON, 0);
 	if (preempt_trace() && !irq_trace())
 		stop_critical_timing(a0, a1);
 }
 
 void trace_preempt_off(unsigned long a0, unsigned long a1)
 {
+	trace_preemptirqsoff_hist(PREEMPT_ON, 1);
 	if (preempt_trace() && !irq_trace())
 		start_critical_timing(a0, a1);
 }
diff -Nur linux-3.18.12.orig/kernel/trace/trace_output.c linux-3.18.12/kernel/trace/trace_output.c
--- linux-3.18.12.orig/kernel/trace/trace_output.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/trace/trace_output.c	2015-04-26 13:32:22.455684003 -0500
@@ -410,6 +410,7 @@
 {
 	char hardsoft_irq;
 	char need_resched;
+	char need_resched_lazy;
 	char irqs_off;
 	int hardirq;
 	int softirq;
@@ -438,6 +439,8 @@
 		need_resched = '.';
 		break;
 	}
+	need_resched_lazy =
+		(entry->flags & TRACE_FLAG_NEED_RESCHED_LAZY) ? 'L' : '.';
 
 	hardsoft_irq =
 		(hardirq && softirq) ? 'H' :
@@ -445,8 +448,9 @@
 		softirq ? 's' :
 		'.';
 
-	if (!trace_seq_printf(s, "%c%c%c",
-			      irqs_off, need_resched, hardsoft_irq))
+	if (!trace_seq_printf(s, "%c%c%c%c",
+			      irqs_off, need_resched, need_resched_lazy,
+			      hardsoft_irq))
 		return 0;
 
 	if (entry->preempt_count)
@@ -454,6 +458,16 @@
 	else
 		ret = trace_seq_putc(s, '.');
 
+	if (entry->preempt_lazy_count)
+		ret = trace_seq_printf(s, "%x", entry->preempt_lazy_count);
+	else
+		ret = trace_seq_putc(s, '.');
+
+	if (entry->migrate_disable)
+		ret = trace_seq_printf(s, "%x", entry->migrate_disable);
+	else
+		ret = trace_seq_putc(s, '.');
+
 	return ret;
 }
 
diff -Nur linux-3.18.12.orig/kernel/user.c linux-3.18.12/kernel/user.c
--- linux-3.18.12.orig/kernel/user.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/user.c	2015-04-26 13:32:22.455684003 -0500
@@ -158,11 +158,11 @@
 	if (!up)
 		return;
 
-	local_irq_save(flags);
+	local_irq_save_nort(flags);
 	if (atomic_dec_and_lock(&up->__count, &uidhash_lock))
 		free_user(up, flags);
 	else
-		local_irq_restore(flags);
+		local_irq_restore_nort(flags);
 }
 
 struct user_struct *alloc_uid(kuid_t uid)
diff -Nur linux-3.18.12.orig/kernel/watchdog.c linux-3.18.12/kernel/watchdog.c
--- linux-3.18.12.orig/kernel/watchdog.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/watchdog.c	2015-04-26 13:32:22.459684003 -0500
@@ -248,6 +248,8 @@
 
 #ifdef CONFIG_HARDLOCKUP_DETECTOR
 
+static DEFINE_RAW_SPINLOCK(watchdog_output_lock);
+
 static struct perf_event_attr wd_hw_attr = {
 	.type		= PERF_TYPE_HARDWARE,
 	.config		= PERF_COUNT_HW_CPU_CYCLES,
@@ -281,13 +283,21 @@
 		/* only print hardlockups once */
 		if (__this_cpu_read(hard_watchdog_warn) == true)
 			return;
+		/*
+		 * If early-printk is enabled then make sure we do not
+		 * lock up in printk() and kill console logging:
+		 */
+		printk_kill();
 
-		if (hardlockup_panic)
+		if (hardlockup_panic) {
 			panic("Watchdog detected hard LOCKUP on cpu %d",
 			      this_cpu);
-		else
+		} else {
+			raw_spin_lock(&watchdog_output_lock);
 			WARN(1, "Watchdog detected hard LOCKUP on cpu %d",
 			     this_cpu);
+			raw_spin_unlock(&watchdog_output_lock);
+		}
 
 		__this_cpu_write(hard_watchdog_warn, true);
 		return;
@@ -430,6 +440,7 @@
 	/* kick off the timer for the hardlockup detector */
 	hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 	hrtimer->function = watchdog_timer_fn;
+	hrtimer->irqsafe = 1;
 
 	/* Enable the perf event */
 	watchdog_nmi_enable(cpu);
diff -Nur linux-3.18.12.orig/kernel/workqueue.c linux-3.18.12/kernel/workqueue.c
--- linux-3.18.12.orig/kernel/workqueue.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/workqueue.c	2015-04-26 13:32:22.459684003 -0500
@@ -48,6 +48,8 @@
 #include <linux/nodemask.h>
 #include <linux/moduleparam.h>
 #include <linux/uaccess.h>
+#include <linux/locallock.h>
+#include <linux/delay.h>
 
 #include "workqueue_internal.h"
 
@@ -121,15 +123,20 @@
  *    cpu or grabbing pool->lock is enough for read access.  If
  *    POOL_DISASSOCIATED is set, it's identical to L.
  *
+ *    On RT we need the extra protection via rt_lock_idle_list() for
+ *    the list manipulations against read access from
+ *    wq_worker_sleeping(). All other places are nicely serialized via
+ *    pool->lock.
+ *
  * A: pool->attach_mutex protected.
  *
  * PL: wq_pool_mutex protected.
  *
- * PR: wq_pool_mutex protected for writes.  Sched-RCU protected for reads.
+ * PR: wq_pool_mutex protected for writes.  RCU protected for reads.
  *
  * WQ: wq->mutex protected.
  *
- * WR: wq->mutex protected for writes.  Sched-RCU protected for reads.
+ * WR: wq->mutex protected for writes.  RCU protected for reads.
  *
  * MD: wq_mayday_lock protected.
  */
@@ -177,7 +184,7 @@
 	atomic_t		nr_running ____cacheline_aligned_in_smp;
 
 	/*
-	 * Destruction of pool is sched-RCU protected to allow dereferences
+	 * Destruction of pool is RCU protected to allow dereferences
 	 * from get_work_pool().
 	 */
 	struct rcu_head		rcu;
@@ -206,7 +213,7 @@
 	/*
 	 * Release of unbound pwq is punted to system_wq.  See put_pwq()
 	 * and pwq_unbound_release_workfn() for details.  pool_workqueue
-	 * itself is also sched-RCU protected so that the first pwq can be
+	 * itself is also RCU protected so that the first pwq can be
 	 * determined without grabbing wq->mutex.
 	 */
 	struct work_struct	unbound_release_work;
@@ -321,6 +328,8 @@
 struct workqueue_struct *system_freezable_power_efficient_wq __read_mostly;
 EXPORT_SYMBOL_GPL(system_freezable_power_efficient_wq);
 
+static DEFINE_LOCAL_IRQ_LOCK(pendingb_lock);
+
 static int worker_thread(void *__worker);
 static void copy_workqueue_attrs(struct workqueue_attrs *to,
 				 const struct workqueue_attrs *from);
@@ -329,14 +338,14 @@
 #include <trace/events/workqueue.h>
 
 #define assert_rcu_or_pool_mutex()					\
-	rcu_lockdep_assert(rcu_read_lock_sched_held() ||		\
+	rcu_lockdep_assert(rcu_read_lock_held() ||			\
 			   lockdep_is_held(&wq_pool_mutex),		\
-			   "sched RCU or wq_pool_mutex should be held")
+			   "RCU or wq_pool_mutex should be held")
 
 #define assert_rcu_or_wq_mutex(wq)					\
-	rcu_lockdep_assert(rcu_read_lock_sched_held() ||		\
+	rcu_lockdep_assert(rcu_read_lock_held() ||			\
 			   lockdep_is_held(&wq->mutex),			\
-			   "sched RCU or wq->mutex should be held")
+			   "RCU or wq->mutex should be held")
 
 #define for_each_cpu_worker_pool(pool, cpu)				\
 	for ((pool) = &per_cpu(cpu_worker_pools, cpu)[0];		\
@@ -348,7 +357,7 @@
  * @pool: iteration cursor
  * @pi: integer used for iteration
  *
- * This must be called either with wq_pool_mutex held or sched RCU read
+ * This must be called either with wq_pool_mutex held or RCU read
  * locked.  If the pool needs to be used beyond the locking in effect, the
  * caller is responsible for guaranteeing that the pool stays online.
  *
@@ -380,7 +389,7 @@
  * @pwq: iteration cursor
  * @wq: the target workqueue
  *
- * This must be called either with wq->mutex held or sched RCU read locked.
+ * This must be called either with wq->mutex held or RCU read locked.
  * If the pwq needs to be used beyond the locking in effect, the caller is
  * responsible for guaranteeing that the pwq stays online.
  *
@@ -392,6 +401,31 @@
 		if (({ assert_rcu_or_wq_mutex(wq); false; })) { }	\
 		else
 
+#ifdef CONFIG_PREEMPT_RT_BASE
+static inline void rt_lock_idle_list(struct worker_pool *pool)
+{
+	preempt_disable();
+}
+static inline void rt_unlock_idle_list(struct worker_pool *pool)
+{
+	preempt_enable();
+}
+static inline void sched_lock_idle_list(struct worker_pool *pool) { }
+static inline void sched_unlock_idle_list(struct worker_pool *pool) { }
+#else
+static inline void rt_lock_idle_list(struct worker_pool *pool) { }
+static inline void rt_unlock_idle_list(struct worker_pool *pool) { }
+static inline void sched_lock_idle_list(struct worker_pool *pool)
+{
+	spin_lock_irq(&pool->lock);
+}
+static inline void sched_unlock_idle_list(struct worker_pool *pool)
+{
+	spin_unlock_irq(&pool->lock);
+}
+#endif
+
+
 #ifdef CONFIG_DEBUG_OBJECTS_WORK
 
 static struct debug_obj_descr work_debug_descr;
@@ -542,7 +576,7 @@
  * @wq: the target workqueue
  * @node: the node ID
  *
- * This must be called either with pwq_lock held or sched RCU read locked.
+ * This must be called either with pwq_lock held or RCU read locked.
  * If the pwq needs to be used beyond the locking in effect, the caller is
  * responsible for guaranteeing that the pwq stays online.
  *
@@ -646,8 +680,8 @@
  * @work: the work item of interest
  *
  * Pools are created and destroyed under wq_pool_mutex, and allows read
- * access under sched-RCU read lock.  As such, this function should be
- * called under wq_pool_mutex or with preemption disabled.
+ * access under RCU read lock.  As such, this function should be
+ * called under wq_pool_mutex or inside of a rcu_read_lock() region.
  *
  * All fields of the returned pool are accessible as long as the above
  * mentioned locking is in effect.  If the returned pool needs to be used
@@ -784,51 +818,44 @@
  */
 static void wake_up_worker(struct worker_pool *pool)
 {
-	struct worker *worker = first_idle_worker(pool);
+	struct worker *worker;
+
+	rt_lock_idle_list(pool);
+
+	worker = first_idle_worker(pool);
 
 	if (likely(worker))
 		wake_up_process(worker->task);
+
+	rt_unlock_idle_list(pool);
 }
 
 /**
- * wq_worker_waking_up - a worker is waking up
- * @task: task waking up
- * @cpu: CPU @task is waking up to
- *
- * This function is called during try_to_wake_up() when a worker is
- * being awoken.
+ * wq_worker_running - a worker is running again
+ * @task: task returning from sleep
  *
- * CONTEXT:
- * spin_lock_irq(rq->lock)
+ * This function is called when a worker returns from schedule()
  */
-void wq_worker_waking_up(struct task_struct *task, int cpu)
+void wq_worker_running(struct task_struct *task)
 {
 	struct worker *worker = kthread_data(task);
 
-	if (!(worker->flags & WORKER_NOT_RUNNING)) {
-		WARN_ON_ONCE(worker->pool->cpu != cpu);
+	if (!worker->sleeping)
+		return;
+	if (!(worker->flags & WORKER_NOT_RUNNING))
 		atomic_inc(&worker->pool->nr_running);
-	}
+	worker->sleeping = 0;
 }
 
 /**
  * wq_worker_sleeping - a worker is going to sleep
  * @task: task going to sleep
- * @cpu: CPU in question, must be the current CPU number
- *
- * This function is called during schedule() when a busy worker is
- * going to sleep.  Worker on the same cpu can be woken up by
- * returning pointer to its task.
- *
- * CONTEXT:
- * spin_lock_irq(rq->lock)
- *
- * Return:
- * Worker task on @cpu to wake up, %NULL if none.
+ * This function is called from schedule() when a busy worker is
+ * going to sleep.
  */
-struct task_struct *wq_worker_sleeping(struct task_struct *task, int cpu)
+void wq_worker_sleeping(struct task_struct *task)
 {
-	struct worker *worker = kthread_data(task), *to_wakeup = NULL;
+	struct worker *worker = kthread_data(task);
 	struct worker_pool *pool;
 
 	/*
@@ -837,29 +864,26 @@
 	 * checking NOT_RUNNING.
 	 */
 	if (worker->flags & WORKER_NOT_RUNNING)
-		return NULL;
+		return;
 
 	pool = worker->pool;
 
-	/* this can only happen on the local cpu */
-	if (WARN_ON_ONCE(cpu != raw_smp_processor_id() || pool->cpu != cpu))
-		return NULL;
+	if (WARN_ON_ONCE(worker->sleeping))
+		return;
+
+	worker->sleeping = 1;
 
 	/*
 	 * The counterpart of the following dec_and_test, implied mb,
 	 * worklist not empty test sequence is in insert_work().
 	 * Please read comment there.
-	 *
-	 * NOT_RUNNING is clear.  This means that we're bound to and
-	 * running on the local cpu w/ rq lock held and preemption
-	 * disabled, which in turn means that none else could be
-	 * manipulating idle_list, so dereferencing idle_list without pool
-	 * lock is safe.
 	 */
 	if (atomic_dec_and_test(&pool->nr_running) &&
-	    !list_empty(&pool->worklist))
-		to_wakeup = first_idle_worker(pool);
-	return to_wakeup ? to_wakeup->task : NULL;
+	    !list_empty(&pool->worklist)) {
+		sched_lock_idle_list(pool);
+		wake_up_worker(pool);
+		sched_unlock_idle_list(pool);
+	}
 }
 
 /**
@@ -1053,12 +1077,12 @@
 {
 	if (pwq) {
 		/*
-		 * As both pwqs and pools are sched-RCU protected, the
+		 * As both pwqs and pools are RCU protected, the
 		 * following lock operations are safe.
 		 */
-		spin_lock_irq(&pwq->pool->lock);
+		local_spin_lock_irq(pendingb_lock, &pwq->pool->lock);
 		put_pwq(pwq);
-		spin_unlock_irq(&pwq->pool->lock);
+		local_spin_unlock_irq(pendingb_lock, &pwq->pool->lock);
 	}
 }
 
@@ -1160,7 +1184,7 @@
 	struct worker_pool *pool;
 	struct pool_workqueue *pwq;
 
-	local_irq_save(*flags);
+	local_lock_irqsave(pendingb_lock, *flags);
 
 	/* try to steal the timer if it exists */
 	if (is_dwork) {
@@ -1179,6 +1203,7 @@
 	if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work)))
 		return 0;
 
+	rcu_read_lock();
 	/*
 	 * The queueing is in progress, or it is already queued. Try to
 	 * steal it from ->worklist without clearing WORK_STRUCT_PENDING.
@@ -1217,14 +1242,16 @@
 		set_work_pool_and_keep_pending(work, pool->id);
 
 		spin_unlock(&pool->lock);
+		rcu_read_unlock();
 		return 1;
 	}
 	spin_unlock(&pool->lock);
 fail:
-	local_irq_restore(*flags);
+	rcu_read_unlock();
+	local_unlock_irqrestore(pendingb_lock, *flags);
 	if (work_is_canceling(work))
 		return -ENOENT;
-	cpu_relax();
+	cpu_chill();
 	return -EAGAIN;
 }
 
@@ -1293,7 +1320,7 @@
 	 * queued or lose PENDING.  Grabbing PENDING and queueing should
 	 * happen with IRQ disabled.
 	 */
-	WARN_ON_ONCE(!irqs_disabled());
+	WARN_ON_ONCE_NONRT(!irqs_disabled());
 
 	debug_work_activate(work);
 
@@ -1301,6 +1328,8 @@
 	if (unlikely(wq->flags & __WQ_DRAINING) &&
 	    WARN_ON_ONCE(!is_chained_work(wq)))
 		return;
+
+	rcu_read_lock();
 retry:
 	if (req_cpu == WORK_CPU_UNBOUND)
 		cpu = raw_smp_processor_id();
@@ -1357,10 +1386,8 @@
 	/* pwq determined, queue */
 	trace_workqueue_queue_work(req_cpu, pwq, work);
 
-	if (WARN_ON(!list_empty(&work->entry))) {
-		spin_unlock(&pwq->pool->lock);
-		return;
-	}
+	if (WARN_ON(!list_empty(&work->entry)))
+		goto out;
 
 	pwq->nr_in_flight[pwq->work_color]++;
 	work_flags = work_color_to_flags(pwq->work_color);
@@ -1376,7 +1403,9 @@
 
 	insert_work(pwq, work, worklist, work_flags);
 
+out:
 	spin_unlock(&pwq->pool->lock);
+	rcu_read_unlock();
 }
 
 /**
@@ -1396,14 +1425,14 @@
 	bool ret = false;
 	unsigned long flags;
 
-	local_irq_save(flags);
+	local_lock_irqsave(pendingb_lock,flags);
 
 	if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) {
 		__queue_work(cpu, wq, work);
 		ret = true;
 	}
 
-	local_irq_restore(flags);
+	local_unlock_irqrestore(pendingb_lock, flags);
 	return ret;
 }
 EXPORT_SYMBOL(queue_work_on);
@@ -1470,14 +1499,14 @@
 	unsigned long flags;
 
 	/* read the comment in __queue_work() */
-	local_irq_save(flags);
+	local_lock_irqsave(pendingb_lock, flags);
 
 	if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) {
 		__queue_delayed_work(cpu, wq, dwork, delay);
 		ret = true;
 	}
 
-	local_irq_restore(flags);
+	local_unlock_irqrestore(pendingb_lock, flags);
 	return ret;
 }
 EXPORT_SYMBOL(queue_delayed_work_on);
@@ -1512,7 +1541,7 @@
 
 	if (likely(ret >= 0)) {
 		__queue_delayed_work(cpu, wq, dwork, delay);
-		local_irq_restore(flags);
+		local_unlock_irqrestore(pendingb_lock, flags);
 	}
 
 	/* -ENOENT from try_to_grab_pending() becomes %true */
@@ -1545,7 +1574,9 @@
 	worker->last_active = jiffies;
 
 	/* idle_list is LIFO */
+	rt_lock_idle_list(pool);
 	list_add(&worker->entry, &pool->idle_list);
+	rt_unlock_idle_list(pool);
 
 	if (too_many_workers(pool) && !timer_pending(&pool->idle_timer))
 		mod_timer(&pool->idle_timer, jiffies + IDLE_WORKER_TIMEOUT);
@@ -1578,7 +1609,9 @@
 		return;
 	worker_clr_flags(worker, WORKER_IDLE);
 	pool->nr_idle--;
+	rt_lock_idle_list(pool);
 	list_del_init(&worker->entry);
+	rt_unlock_idle_list(pool);
 }
 
 static struct worker *alloc_worker(int node)
@@ -1746,7 +1779,9 @@
 	pool->nr_workers--;
 	pool->nr_idle--;
 
+	rt_lock_idle_list(pool);
 	list_del_init(&worker->entry);
+	rt_unlock_idle_list(pool);
 	worker->flags |= WORKER_DIE;
 	wake_up_process(worker->task);
 }
@@ -2641,14 +2676,14 @@
 
 	might_sleep();
 
-	local_irq_disable();
+	rcu_read_lock();
 	pool = get_work_pool(work);
 	if (!pool) {
-		local_irq_enable();
+		rcu_read_unlock();
 		return false;
 	}
 
-	spin_lock(&pool->lock);
+	spin_lock_irq(&pool->lock);
 	/* see the comment in try_to_grab_pending() with the same code */
 	pwq = get_work_pwq(work);
 	if (pwq) {
@@ -2675,10 +2710,11 @@
 	else
 		lock_map_acquire_read(&pwq->wq->lockdep_map);
 	lock_map_release(&pwq->wq->lockdep_map);
-
+	rcu_read_unlock();
 	return true;
 already_gone:
 	spin_unlock_irq(&pool->lock);
+	rcu_read_unlock();
 	return false;
 }
 
@@ -2765,7 +2801,7 @@
 
 	/* tell other tasks trying to grab @work to back off */
 	mark_work_canceling(work);
-	local_irq_restore(flags);
+	local_unlock_irqrestore(pendingb_lock, flags);
 
 	flush_work(work);
 	clear_work_data(work);
@@ -2820,10 +2856,10 @@
  */
 bool flush_delayed_work(struct delayed_work *dwork)
 {
-	local_irq_disable();
+	local_lock_irq(pendingb_lock);
 	if (del_timer_sync(&dwork->timer))
 		__queue_work(dwork->cpu, dwork->wq, &dwork->work);
-	local_irq_enable();
+	local_unlock_irq(pendingb_lock);
 	return flush_work(&dwork->work);
 }
 EXPORT_SYMBOL(flush_delayed_work);
@@ -2858,7 +2894,7 @@
 
 	set_work_pool_and_clear_pending(&dwork->work,
 					get_work_pool_id(&dwork->work));
-	local_irq_restore(flags);
+	local_unlock_irqrestore(pendingb_lock, flags);
 	return ret;
 }
 EXPORT_SYMBOL(cancel_delayed_work);
@@ -3044,7 +3080,8 @@
 	const char *delim = "";
 	int node, written = 0;
 
-	rcu_read_lock_sched();
+	get_online_cpus();
+	rcu_read_lock();
 	for_each_node(node) {
 		written += scnprintf(buf + written, PAGE_SIZE - written,
 				     "%s%d:%d", delim, node,
@@ -3052,7 +3089,8 @@
 		delim = " ";
 	}
 	written += scnprintf(buf + written, PAGE_SIZE - written, "\n");
-	rcu_read_unlock_sched();
+	rcu_read_unlock();
+	put_online_cpus();
 
 	return written;
 }
@@ -3420,7 +3458,7 @@
  * put_unbound_pool - put a worker_pool
  * @pool: worker_pool to put
  *
- * Put @pool.  If its refcnt reaches zero, it gets destroyed in sched-RCU
+ * Put @pool.  If its refcnt reaches zero, it gets destroyed in RCU
  * safe manner.  get_unbound_pool() calls this function on its failure path
  * and this function should be able to release pools which went through,
  * successfully or not, init_worker_pool().
@@ -3474,8 +3512,8 @@
 	del_timer_sync(&pool->idle_timer);
 	del_timer_sync(&pool->mayday_timer);
 
-	/* sched-RCU protected to allow dereferences from get_work_pool() */
-	call_rcu_sched(&pool->rcu, rcu_free_pool);
+	/* RCU protected to allow dereferences from get_work_pool() */
+	call_rcu(&pool->rcu, rcu_free_pool);
 }
 
 /**
@@ -3580,7 +3618,7 @@
 	put_unbound_pool(pool);
 	mutex_unlock(&wq_pool_mutex);
 
-	call_rcu_sched(&pwq->rcu, rcu_free_pwq);
+	call_rcu(&pwq->rcu, rcu_free_pwq);
 
 	/*
 	 * If we're the last pwq going away, @wq is already dead and no one
@@ -4292,7 +4330,8 @@
 	struct pool_workqueue *pwq;
 	bool ret;
 
-	rcu_read_lock_sched();
+	rcu_read_lock();
+	preempt_disable();
 
 	if (cpu == WORK_CPU_UNBOUND)
 		cpu = smp_processor_id();
@@ -4303,7 +4342,8 @@
 		pwq = unbound_pwq_by_node(wq, cpu_to_node(cpu));
 
 	ret = !list_empty(&pwq->delayed_works);
-	rcu_read_unlock_sched();
+	preempt_enable();
+	rcu_read_unlock();
 
 	return ret;
 }
@@ -4329,16 +4369,15 @@
 	if (work_pending(work))
 		ret |= WORK_BUSY_PENDING;
 
-	local_irq_save(flags);
+	rcu_read_lock();
 	pool = get_work_pool(work);
 	if (pool) {
-		spin_lock(&pool->lock);
+		spin_lock_irqsave(&pool->lock, flags);
 		if (find_worker_executing_work(pool, work))
 			ret |= WORK_BUSY_RUNNING;
-		spin_unlock(&pool->lock);
+		spin_unlock_irqrestore(&pool->lock, flags);
 	}
-	local_irq_restore(flags);
-
+	rcu_read_unlock();
 	return ret;
 }
 EXPORT_SYMBOL_GPL(work_busy);
@@ -4767,16 +4806,16 @@
 		 * nr_active is monotonically decreasing.  It's safe
 		 * to peek without lock.
 		 */
-		rcu_read_lock_sched();
+		rcu_read_lock();
 		for_each_pwq(pwq, wq) {
 			WARN_ON_ONCE(pwq->nr_active < 0);
 			if (pwq->nr_active) {
 				busy = true;
-				rcu_read_unlock_sched();
+				rcu_read_unlock();
 				goto out_unlock;
 			}
 		}
-		rcu_read_unlock_sched();
+		rcu_read_unlock();
 	}
 out_unlock:
 	mutex_unlock(&wq_pool_mutex);
diff -Nur linux-3.18.12.orig/kernel/workqueue_internal.h linux-3.18.12/kernel/workqueue_internal.h
--- linux-3.18.12.orig/kernel/workqueue_internal.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/kernel/workqueue_internal.h	2015-04-26 13:32:22.459684003 -0500
@@ -43,6 +43,7 @@
 	unsigned long		last_active;	/* L: last active timestamp */
 	unsigned int		flags;		/* X: flags */
 	int			id;		/* I: worker id */
+	int			sleeping;	/* None */
 
 	/*
 	 * Opaque string set with work_set_desc().  Printed out with task
@@ -68,7 +69,7 @@
  * Scheduler hooks for concurrency managed workqueue.  Only to be used from
  * sched/core.c and workqueue.c.
  */
-void wq_worker_waking_up(struct task_struct *task, int cpu);
-struct task_struct *wq_worker_sleeping(struct task_struct *task, int cpu);
+void wq_worker_running(struct task_struct *task);
+void wq_worker_sleeping(struct task_struct *task);
 
 #endif /* _KERNEL_WORKQUEUE_INTERNAL_H */
diff -Nur linux-3.18.12.orig/lib/debugobjects.c linux-3.18.12/lib/debugobjects.c
--- linux-3.18.12.orig/lib/debugobjects.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/lib/debugobjects.c	2015-04-26 13:32:22.459684003 -0500
@@ -309,7 +309,10 @@
 	struct debug_obj *obj;
 	unsigned long flags;
 
-	fill_pool();
+#ifdef CONFIG_PREEMPT_RT_FULL
+	if (preempt_count() == 0 && !irqs_disabled())
+#endif
+		fill_pool();
 
 	db = get_bucket((unsigned long) addr);
 
diff -Nur linux-3.18.12.orig/lib/idr.c linux-3.18.12/lib/idr.c
--- linux-3.18.12.orig/lib/idr.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/lib/idr.c	2015-04-26 13:32:22.459684003 -0500
@@ -31,6 +31,7 @@
 #include <linux/spinlock.h>
 #include <linux/percpu.h>
 #include <linux/hardirq.h>
+#include <linux/locallock.h>
 
 #define MAX_IDR_SHIFT		(sizeof(int) * 8 - 1)
 #define MAX_IDR_BIT		(1U << MAX_IDR_SHIFT)
@@ -367,6 +368,35 @@
 	idr_mark_full(pa, id);
 }
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+static DEFINE_LOCAL_IRQ_LOCK(idr_lock);
+
+static inline void idr_preload_lock(void)
+{
+	local_lock(idr_lock);
+}
+
+static inline void idr_preload_unlock(void)
+{
+	local_unlock(idr_lock);
+}
+
+void idr_preload_end(void)
+{
+	idr_preload_unlock();
+}
+EXPORT_SYMBOL(idr_preload_end);
+#else
+static inline void idr_preload_lock(void)
+{
+	preempt_disable();
+}
+
+static inline void idr_preload_unlock(void)
+{
+	preempt_enable();
+}
+#endif
 
 /**
  * idr_preload - preload for idr_alloc()
@@ -402,7 +432,7 @@
 	WARN_ON_ONCE(in_interrupt());
 	might_sleep_if(gfp_mask & __GFP_WAIT);
 
-	preempt_disable();
+	idr_preload_lock();
 
 	/*
 	 * idr_alloc() is likely to succeed w/o full idr_layer buffer and
@@ -414,9 +444,9 @@
 	while (__this_cpu_read(idr_preload_cnt) < MAX_IDR_FREE) {
 		struct idr_layer *new;
 
-		preempt_enable();
+		idr_preload_unlock();
 		new = kmem_cache_zalloc(idr_layer_cache, gfp_mask);
-		preempt_disable();
+		idr_preload_lock();
 		if (!new)
 			break;
 
diff -Nur linux-3.18.12.orig/lib/Kconfig linux-3.18.12/lib/Kconfig
--- linux-3.18.12.orig/lib/Kconfig	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/lib/Kconfig	2015-04-26 13:32:22.459684003 -0500
@@ -383,6 +383,7 @@
 
 config CPUMASK_OFFSTACK
 	bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS
+	depends on !PREEMPT_RT_FULL
 	help
 	  Use dynamic allocation for cpumask_var_t, instead of putting
 	  them on the stack.  This is a bit more expensive, but avoids
diff -Nur linux-3.18.12.orig/lib/Kconfig.debug linux-3.18.12/lib/Kconfig.debug
--- linux-3.18.12.orig/lib/Kconfig.debug	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/lib/Kconfig.debug	2015-04-26 13:32:22.459684003 -0500
@@ -639,7 +639,7 @@
 
 config DEBUG_SHIRQ
 	bool "Debug shared IRQ handlers"
-	depends on DEBUG_KERNEL
+	depends on DEBUG_KERNEL && !PREEMPT_RT_BASE
 	help
 	  Enable this to generate a spurious interrupt as soon as a shared
 	  interrupt handler is registered, and just before one is deregistered.
diff -Nur linux-3.18.12.orig/lib/locking-selftest.c linux-3.18.12/lib/locking-selftest.c
--- linux-3.18.12.orig/lib/locking-selftest.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/lib/locking-selftest.c	2015-04-26 13:32:22.459684003 -0500
@@ -590,6 +590,8 @@
 #include "locking-selftest-spin-hardirq.h"
 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_hard_spin)
 
+#ifndef CONFIG_PREEMPT_RT_FULL
+
 #include "locking-selftest-rlock-hardirq.h"
 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_hard_rlock)
 
@@ -605,9 +607,12 @@
 #include "locking-selftest-wlock-softirq.h"
 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_soft_wlock)
 
+#endif
+
 #undef E1
 #undef E2
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 /*
  * Enabling hardirqs with a softirq-safe lock held:
  */
@@ -640,6 +645,8 @@
 #undef E1
 #undef E2
 
+#endif
+
 /*
  * Enabling irqs with an irq-safe lock held:
  */
@@ -663,6 +670,8 @@
 #include "locking-selftest-spin-hardirq.h"
 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_hard_spin)
 
+#ifndef CONFIG_PREEMPT_RT_FULL
+
 #include "locking-selftest-rlock-hardirq.h"
 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_hard_rlock)
 
@@ -678,6 +687,8 @@
 #include "locking-selftest-wlock-softirq.h"
 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_soft_wlock)
 
+#endif
+
 #undef E1
 #undef E2
 
@@ -709,6 +720,8 @@
 #include "locking-selftest-spin-hardirq.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_hard_spin)
 
+#ifndef CONFIG_PREEMPT_RT_FULL
+
 #include "locking-selftest-rlock-hardirq.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_hard_rlock)
 
@@ -724,6 +737,8 @@
 #include "locking-selftest-wlock-softirq.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_soft_wlock)
 
+#endif
+
 #undef E1
 #undef E2
 #undef E3
@@ -757,6 +772,8 @@
 #include "locking-selftest-spin-hardirq.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_hard_spin)
 
+#ifndef CONFIG_PREEMPT_RT_FULL
+
 #include "locking-selftest-rlock-hardirq.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_hard_rlock)
 
@@ -772,10 +789,14 @@
 #include "locking-selftest-wlock-softirq.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_soft_wlock)
 
+#endif
+
 #undef E1
 #undef E2
 #undef E3
 
+#ifndef CONFIG_PREEMPT_RT_FULL
+
 /*
  * read-lock / write-lock irq inversion.
  *
@@ -838,6 +859,10 @@
 #undef E2
 #undef E3
 
+#endif
+
+#ifndef CONFIG_PREEMPT_RT_FULL
+
 /*
  * read-lock / write-lock recursion that is actually safe.
  */
@@ -876,6 +901,8 @@
 #undef E2
 #undef E3
 
+#endif
+
 /*
  * read-lock / write-lock recursion that is unsafe.
  */
@@ -1858,6 +1885,7 @@
 
 	printk("  --------------------------------------------------------------------------\n");
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 	/*
 	 * irq-context testcases:
 	 */
@@ -1870,6 +1898,28 @@
 
 	DO_TESTCASE_6x2("irq read-recursion", irq_read_recursion);
 //	DO_TESTCASE_6x2B("irq read-recursion #2", irq_read_recursion2);
+#else
+	/* On -rt, we only do hardirq context test for raw spinlock */
+	DO_TESTCASE_1B("hard-irqs-on + irq-safe-A", irqsafe1_hard_spin, 12);
+	DO_TESTCASE_1B("hard-irqs-on + irq-safe-A", irqsafe1_hard_spin, 21);
+
+	DO_TESTCASE_1B("hard-safe-A + irqs-on", irqsafe2B_hard_spin, 12);
+	DO_TESTCASE_1B("hard-safe-A + irqs-on", irqsafe2B_hard_spin, 21);
+
+	DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 123);
+	DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 132);
+	DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 213);
+	DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 231);
+	DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 312);
+	DO_TESTCASE_1B("hard-safe-A + unsafe-B #1", irqsafe3_hard_spin, 321);
+
+	DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 123);
+	DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 132);
+	DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 213);
+	DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 231);
+	DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 312);
+	DO_TESTCASE_1B("hard-safe-A + unsafe-B #2", irqsafe4_hard_spin, 321);
+#endif
 
 	ww_tests();
 
diff -Nur linux-3.18.12.orig/lib/percpu_ida.c linux-3.18.12/lib/percpu_ida.c
--- linux-3.18.12.orig/lib/percpu_ida.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/lib/percpu_ida.c	2015-04-26 13:32:22.459684003 -0500
@@ -29,6 +29,9 @@
 #include <linux/string.h>
 #include <linux/spinlock.h>
 #include <linux/percpu_ida.h>
+#include <linux/locallock.h>
+
+static DEFINE_LOCAL_IRQ_LOCK(irq_off_lock);
 
 struct percpu_ida_cpu {
 	/*
@@ -151,13 +154,13 @@
 	unsigned long flags;
 	int tag;
 
-	local_irq_save(flags);
+	local_lock_irqsave(irq_off_lock, flags);
 	tags = this_cpu_ptr(pool->tag_cpu);
 
 	/* Fastpath */
 	tag = alloc_local_tag(tags);
 	if (likely(tag >= 0)) {
-		local_irq_restore(flags);
+		local_unlock_irqrestore(irq_off_lock, flags);
 		return tag;
 	}
 
@@ -176,6 +179,7 @@
 
 		if (!tags->nr_free)
 			alloc_global_tags(pool, tags);
+
 		if (!tags->nr_free)
 			steal_tags(pool, tags);
 
@@ -187,7 +191,7 @@
 		}
 
 		spin_unlock(&pool->lock);
-		local_irq_restore(flags);
+		local_unlock_irqrestore(irq_off_lock, flags);
 
 		if (tag >= 0 || state == TASK_RUNNING)
 			break;
@@ -199,7 +203,7 @@
 
 		schedule();
 
-		local_irq_save(flags);
+		local_lock_irqsave(irq_off_lock, flags);
 		tags = this_cpu_ptr(pool->tag_cpu);
 	}
 	if (state != TASK_RUNNING)
@@ -224,7 +228,7 @@
 
 	BUG_ON(tag >= pool->nr_tags);
 
-	local_irq_save(flags);
+	local_lock_irqsave(irq_off_lock, flags);
 	tags = this_cpu_ptr(pool->tag_cpu);
 
 	spin_lock(&tags->lock);
@@ -256,7 +260,7 @@
 		spin_unlock(&pool->lock);
 	}
 
-	local_irq_restore(flags);
+	local_unlock_irqrestore(irq_off_lock, flags);
 }
 EXPORT_SYMBOL_GPL(percpu_ida_free);
 
@@ -348,7 +352,7 @@
 	struct percpu_ida_cpu *remote;
 	unsigned cpu, i, err = 0;
 
-	local_irq_save(flags);
+	local_lock_irqsave(irq_off_lock, flags);
 	for_each_possible_cpu(cpu) {
 		remote = per_cpu_ptr(pool->tag_cpu, cpu);
 		spin_lock(&remote->lock);
@@ -370,7 +374,7 @@
 	}
 	spin_unlock(&pool->lock);
 out:
-	local_irq_restore(flags);
+	local_unlock_irqrestore(irq_off_lock, flags);
 	return err;
 }
 EXPORT_SYMBOL_GPL(percpu_ida_for_each_free);
diff -Nur linux-3.18.12.orig/lib/radix-tree.c linux-3.18.12/lib/radix-tree.c
--- linux-3.18.12.orig/lib/radix-tree.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/lib/radix-tree.c	2015-04-26 13:32:22.459684003 -0500
@@ -195,12 +195,13 @@
 		 * succeed in getting a node here (and never reach
 		 * kmem_cache_alloc)
 		 */
-		rtp = this_cpu_ptr(&radix_tree_preloads);
+		rtp = &get_cpu_var(radix_tree_preloads);
 		if (rtp->nr) {
 			ret = rtp->nodes[rtp->nr - 1];
 			rtp->nodes[rtp->nr - 1] = NULL;
 			rtp->nr--;
 		}
+		put_cpu_var(radix_tree_preloads);
 		/*
 		 * Update the allocation stack trace as this is more useful
 		 * for debugging.
@@ -240,6 +241,7 @@
 	call_rcu(&node->rcu_head, radix_tree_node_rcu_free);
 }
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 /*
  * Load up this CPU's radix_tree_node buffer with sufficient objects to
  * ensure that the addition of a single element in the tree cannot fail.  On
@@ -305,6 +307,7 @@
 	return 0;
 }
 EXPORT_SYMBOL(radix_tree_maybe_preload);
+#endif
 
 /*
  *	Return the maximum key which can be store into a
diff -Nur linux-3.18.12.orig/lib/scatterlist.c linux-3.18.12/lib/scatterlist.c
--- linux-3.18.12.orig/lib/scatterlist.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/lib/scatterlist.c	2015-04-26 13:32:22.459684003 -0500
@@ -592,7 +592,7 @@
 			flush_kernel_dcache_page(miter->page);
 
 		if (miter->__flags & SG_MITER_ATOMIC) {
-			WARN_ON_ONCE(preemptible());
+			WARN_ON_ONCE(!pagefault_disabled());
 			kunmap_atomic(miter->addr);
 		} else
 			kunmap(miter->page);
@@ -637,7 +637,7 @@
 	if (!sg_miter_skip(&miter, skip))
 		return false;
 
-	local_irq_save(flags);
+	local_irq_save_nort(flags);
 
 	while (sg_miter_next(&miter) && offset < buflen) {
 		unsigned int len;
@@ -654,7 +654,7 @@
 
 	sg_miter_stop(&miter);
 
-	local_irq_restore(flags);
+	local_irq_restore_nort(flags);
 	return offset;
 }
 
diff -Nur linux-3.18.12.orig/lib/smp_processor_id.c linux-3.18.12/lib/smp_processor_id.c
--- linux-3.18.12.orig/lib/smp_processor_id.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/lib/smp_processor_id.c	2015-04-26 13:32:22.459684003 -0500
@@ -39,8 +39,9 @@
 	if (!printk_ratelimit())
 		goto out_enable;
 
-	printk(KERN_ERR "BUG: using %s%s() in preemptible [%08x] code: %s/%d\n",
-		what1, what2, preempt_count() - 1, current->comm, current->pid);
+	printk(KERN_ERR "BUG: using %s%s() in preemptible [%08x %08x] code: %s/%d\n",
+		what1, what2, preempt_count() - 1, __migrate_disabled(current),
+		current->comm, current->pid);
 
 	print_symbol("caller is %s\n", (long)__builtin_return_address(0));
 	dump_stack();
diff -Nur linux-3.18.12.orig/mm/filemap.c linux-3.18.12/mm/filemap.c
--- linux-3.18.12.orig/mm/filemap.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/mm/filemap.c	2015-04-26 13:32:22.463684003 -0500
@@ -168,7 +168,9 @@
 	if (!workingset_node_pages(node) &&
 	    list_empty(&node->private_list)) {
 		node->private_data = mapping;
-		list_lru_add(&workingset_shadow_nodes, &node->private_list);
+		local_lock(workingset_shadow_lock);
+		list_lru_add(&__workingset_shadow_nodes, &node->private_list);
+		local_unlock(workingset_shadow_lock);
 	}
 }
 
@@ -535,9 +537,12 @@
 		 * node->private_list is protected by
 		 * mapping->tree_lock.
 		 */
-		if (!list_empty(&node->private_list))
-			list_lru_del(&workingset_shadow_nodes,
+		if (!list_empty(&node->private_list)) {
+			local_lock(workingset_shadow_lock);
+			list_lru_del(&__workingset_shadow_nodes,
 				     &node->private_list);
+			local_unlock(workingset_shadow_lock);
+		}
 	}
 	return 0;
 }
diff -Nur linux-3.18.12.orig/mm/highmem.c linux-3.18.12/mm/highmem.c
--- linux-3.18.12.orig/mm/highmem.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/mm/highmem.c	2015-04-26 13:32:22.463684003 -0500
@@ -29,10 +29,11 @@
 #include <linux/kgdb.h>
 #include <asm/tlbflush.h>
 
-
+#ifndef CONFIG_PREEMPT_RT_FULL
 #if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
 DEFINE_PER_CPU(int, __kmap_atomic_idx);
 #endif
+#endif
 
 /*
  * Virtual_count is not a pure "count".
@@ -107,8 +108,9 @@
 unsigned long totalhigh_pages __read_mostly;
 EXPORT_SYMBOL(totalhigh_pages);
 
-
+#ifndef CONFIG_PREEMPT_RT_FULL
 EXPORT_PER_CPU_SYMBOL(__kmap_atomic_idx);
+#endif
 
 unsigned int nr_free_highpages (void)
 {
diff -Nur linux-3.18.12.orig/mm/Kconfig linux-3.18.12/mm/Kconfig
--- linux-3.18.12.orig/mm/Kconfig	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/mm/Kconfig	2015-04-26 13:32:22.463684003 -0500
@@ -408,7 +408,7 @@
 
 config TRANSPARENT_HUGEPAGE
 	bool "Transparent Hugepage Support"
-	depends on HAVE_ARCH_TRANSPARENT_HUGEPAGE
+	depends on HAVE_ARCH_TRANSPARENT_HUGEPAGE && !PREEMPT_RT_FULL
 	select COMPACTION
 	help
 	  Transparent Hugepages allows the kernel to use huge pages and
diff -Nur linux-3.18.12.orig/mm/memcontrol.c linux-3.18.12/mm/memcontrol.c
--- linux-3.18.12.orig/mm/memcontrol.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/mm/memcontrol.c	2015-04-26 13:32:22.463684003 -0500
@@ -60,6 +60,8 @@
 #include <net/sock.h>
 #include <net/ip.h>
 #include <net/tcp_memcontrol.h>
+#include <linux/locallock.h>
+
 #include "slab.h"
 
 #include <asm/uaccess.h>
@@ -87,6 +89,7 @@
 #define do_swap_account		0
 #endif
 
+static DEFINE_LOCAL_IRQ_LOCK(event_lock);
 
 static const char * const mem_cgroup_stat_names[] = {
 	"cache",
@@ -2376,14 +2379,17 @@
  */
 static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
 {
-	struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock);
+	struct memcg_stock_pcp *stock;
+	int cpu = get_cpu_light();
+
+	stock = &per_cpu(memcg_stock, cpu);
 
 	if (stock->cached != memcg) { /* reset if necessary */
 		drain_stock(stock);
 		stock->cached = memcg;
 	}
 	stock->nr_pages += nr_pages;
-	put_cpu_var(memcg_stock);
+	put_cpu_light();
 }
 
 /*
@@ -2397,7 +2403,7 @@
 
 	/* Notify other cpus that system-wide "drain" is running */
 	get_online_cpus();
-	curcpu = get_cpu();
+	curcpu = get_cpu_light();
 	for_each_online_cpu(cpu) {
 		struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
 		struct mem_cgroup *memcg;
@@ -2414,7 +2420,7 @@
 				schedule_work_on(cpu, &stock->work);
 		}
 	}
-	put_cpu();
+	put_cpu_light();
 
 	if (!sync)
 		goto out;
@@ -3419,12 +3425,12 @@
 	move_unlock_mem_cgroup(from, &flags);
 	ret = 0;
 
-	local_irq_disable();
+	local_lock_irq(event_lock);
 	mem_cgroup_charge_statistics(to, page, nr_pages);
 	memcg_check_events(to, page);
 	mem_cgroup_charge_statistics(from, page, -nr_pages);
 	memcg_check_events(from, page);
-	local_irq_enable();
+	local_unlock_irq(event_lock);
 out_unlock:
 	unlock_page(page);
 out:
@@ -6406,10 +6412,10 @@
 		VM_BUG_ON_PAGE(!PageTransHuge(page), page);
 	}
 
-	local_irq_disable();
+	local_lock_irq(event_lock);
 	mem_cgroup_charge_statistics(memcg, page, nr_pages);
 	memcg_check_events(memcg, page);
-	local_irq_enable();
+	local_unlock_irq(event_lock);
 
 	if (do_swap_account && PageSwapCache(page)) {
 		swp_entry_t entry = { .val = page_private(page) };
@@ -6468,14 +6474,14 @@
 		memcg_oom_recover(memcg);
 	}
 
-	local_irq_save(flags);
+	local_lock_irqsave(event_lock, flags);
 	__this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS], nr_anon);
 	__this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_CACHE], nr_file);
 	__this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE], nr_huge);
 	__this_cpu_add(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT], pgpgout);
 	__this_cpu_add(memcg->stat->nr_page_events, nr_anon + nr_file);
 	memcg_check_events(memcg, dummy_page);
-	local_irq_restore(flags);
+	local_unlock_irqrestore(event_lock, flags);
 }
 
 static void uncharge_list(struct list_head *page_list)
diff -Nur linux-3.18.12.orig/mm/memory.c linux-3.18.12/mm/memory.c
--- linux-3.18.12.orig/mm/memory.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/mm/memory.c	2015-04-26 13:32:22.463684003 -0500
@@ -3244,6 +3244,32 @@
 	return 0;
 }
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+void pagefault_disable(void)
+{
+	migrate_disable();
+	current->pagefault_disabled++;
+	/*
+	 * make sure to have issued the store before a pagefault
+	 * can hit.
+	 */
+	barrier();
+}
+EXPORT_SYMBOL(pagefault_disable);
+
+void pagefault_enable(void)
+{
+	/*
+	 * make sure to issue those last loads/stores before enabling
+	 * the pagefault handler again.
+	 */
+	barrier();
+	current->pagefault_disabled--;
+	migrate_enable();
+}
+EXPORT_SYMBOL(pagefault_enable);
+#endif
+
 /*
  * By the time we get here, we already hold the mm semaphore
  *
diff -Nur linux-3.18.12.orig/mm/mmu_context.c linux-3.18.12/mm/mmu_context.c
--- linux-3.18.12.orig/mm/mmu_context.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/mm/mmu_context.c	2015-04-26 13:32:22.463684003 -0500
@@ -23,6 +23,7 @@
 	struct task_struct *tsk = current;
 
 	task_lock(tsk);
+	preempt_disable_rt();
 	active_mm = tsk->active_mm;
 	if (active_mm != mm) {
 		atomic_inc(&mm->mm_count);
@@ -30,6 +31,7 @@
 	}
 	tsk->mm = mm;
 	switch_mm(active_mm, mm, tsk);
+	preempt_enable_rt();
 	task_unlock(tsk);
 #ifdef finish_arch_post_lock_switch
 	finish_arch_post_lock_switch();
diff -Nur linux-3.18.12.orig/mm/page_alloc.c linux-3.18.12/mm/page_alloc.c
--- linux-3.18.12.orig/mm/page_alloc.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/mm/page_alloc.c	2015-04-26 13:32:22.463684003 -0500
@@ -59,6 +59,7 @@
 #include <linux/page-debug-flags.h>
 #include <linux/hugetlb.h>
 #include <linux/sched/rt.h>
+#include <linux/locallock.h>
 
 #include <asm/sections.h>
 #include <asm/tlbflush.h>
@@ -230,6 +231,18 @@
 EXPORT_SYMBOL(nr_online_nodes);
 #endif
 
+static DEFINE_LOCAL_IRQ_LOCK(pa_lock);
+
+#ifdef CONFIG_PREEMPT_RT_BASE
+# define cpu_lock_irqsave(cpu, flags)		\
+	local_lock_irqsave_on(pa_lock, flags, cpu)
+# define cpu_unlock_irqrestore(cpu, flags)	\
+	local_unlock_irqrestore_on(pa_lock, flags, cpu)
+#else
+# define cpu_lock_irqsave(cpu, flags)		local_irq_save(flags)
+# define cpu_unlock_irqrestore(cpu, flags)	local_irq_restore(flags)
+#endif
+
 int page_group_by_mobility_disabled __read_mostly;
 
 void set_pageblock_migratetype(struct page *page, int migratetype)
@@ -654,7 +667,7 @@
 }
 
 /*
- * Frees a number of pages from the PCP lists
+ * Frees a number of pages which have been collected from the pcp lists.
  * Assumes all pages on list are in same zone, and of same order.
  * count is the number of pages to free.
  *
@@ -665,18 +678,51 @@
  * pinned" detection logic.
  */
 static void free_pcppages_bulk(struct zone *zone, int count,
-					struct per_cpu_pages *pcp)
+			       struct list_head *list)
 {
-	int migratetype = 0;
-	int batch_free = 0;
 	int to_free = count;
 	unsigned long nr_scanned;
+	unsigned long flags;
+
+	spin_lock_irqsave(&zone->lock, flags);
 
-	spin_lock(&zone->lock);
 	nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
 	if (nr_scanned)
 		__mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
 
+	while (!list_empty(list)) {
+		struct page *page = list_first_entry(list, struct page, lru);
+		int mt;	/* migratetype of the to-be-freed page */
+
+		/* must delete as __free_one_page list manipulates */
+		list_del(&page->lru);
+
+		mt = get_freepage_migratetype(page);
+		if (unlikely(has_isolate_pageblock(zone)))
+			mt = get_pageblock_migratetype(page);
+
+		/* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
+		__free_one_page(page, page_to_pfn(page), zone, 0, mt);
+		trace_mm_page_pcpu_drain(page, 0, mt);
+		to_free--;
+	}
+	WARN_ON(to_free != 0);
+	spin_unlock_irqrestore(&zone->lock, flags);
+}
+
+/*
+ * Moves a number of pages from the PCP lists to free list which
+ * is freed outside of the locked region.
+ *
+ * Assumes all pages on list are in same zone, and of same order.
+ * count is the number of pages to free.
+ */
+static void isolate_pcp_pages(int to_free, struct per_cpu_pages *src,
+			      struct list_head *dst)
+{
+	int migratetype = 0;
+	int batch_free = 0;
+
 	while (to_free) {
 		struct page *page;
 		struct list_head *list;
@@ -692,7 +738,7 @@
 			batch_free++;
 			if (++migratetype == MIGRATE_PCPTYPES)
 				migratetype = 0;
-			list = &pcp->lists[migratetype];
+			list = &src->lists[migratetype];
 		} while (list_empty(list));
 
 		/* This is the only non-empty list. Free them all. */
@@ -700,21 +746,11 @@
 			batch_free = to_free;
 
 		do {
-			int mt;	/* migratetype of the to-be-freed page */
-
-			page = list_entry(list->prev, struct page, lru);
-			/* must delete as __free_one_page list manipulates */
+			page = list_last_entry(list, struct page, lru);
 			list_del(&page->lru);
-			mt = get_freepage_migratetype(page);
-			if (unlikely(has_isolate_pageblock(zone)))
-				mt = get_pageblock_migratetype(page);
-
-			/* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
-			__free_one_page(page, page_to_pfn(page), zone, 0, mt);
-			trace_mm_page_pcpu_drain(page, 0, mt);
+			list_add(&page->lru, dst);
 		} while (--to_free && --batch_free && !list_empty(list));
 	}
-	spin_unlock(&zone->lock);
 }
 
 static void free_one_page(struct zone *zone,
@@ -723,7 +759,9 @@
 				int migratetype)
 {
 	unsigned long nr_scanned;
-	spin_lock(&zone->lock);
+	unsigned long flags;
+
+	spin_lock_irqsave(&zone->lock, flags);
 	nr_scanned = zone_page_state(zone, NR_PAGES_SCANNED);
 	if (nr_scanned)
 		__mod_zone_page_state(zone, NR_PAGES_SCANNED, -nr_scanned);
@@ -733,7 +771,7 @@
 		migratetype = get_pfnblock_migratetype(page, pfn);
 	}
 	__free_one_page(page, pfn, zone, order, migratetype);
-	spin_unlock(&zone->lock);
+	spin_unlock_irqrestore(&zone->lock, flags);
 }
 
 static bool free_pages_prepare(struct page *page, unsigned int order)
@@ -773,11 +811,11 @@
 		return;
 
 	migratetype = get_pfnblock_migratetype(page, pfn);
-	local_irq_save(flags);
+	local_lock_irqsave(pa_lock, flags);
 	__count_vm_events(PGFREE, 1 << order);
 	set_freepage_migratetype(page, migratetype);
 	free_one_page(page_zone(page), page, pfn, order, migratetype);
-	local_irq_restore(flags);
+	local_unlock_irqrestore(pa_lock, flags);
 }
 
 void __init __free_pages_bootmem(struct page *page, unsigned int order)
@@ -1251,16 +1289,18 @@
 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp)
 {
 	unsigned long flags;
+	LIST_HEAD(dst);
 	int to_drain, batch;
 
-	local_irq_save(flags);
+	local_lock_irqsave(pa_lock, flags);
 	batch = ACCESS_ONCE(pcp->batch);
 	to_drain = min(pcp->count, batch);
 	if (to_drain > 0) {
-		free_pcppages_bulk(zone, to_drain, pcp);
+		isolate_pcp_pages(to_drain, pcp, &dst);
 		pcp->count -= to_drain;
 	}
-	local_irq_restore(flags);
+	local_unlock_irqrestore(pa_lock, flags);
+	free_pcppages_bulk(zone, to_drain, &dst);
 }
 #endif
 
@@ -1279,16 +1319,21 @@
 	for_each_populated_zone(zone) {
 		struct per_cpu_pageset *pset;
 		struct per_cpu_pages *pcp;
+		LIST_HEAD(dst);
+		int count;
 
-		local_irq_save(flags);
+		cpu_lock_irqsave(cpu, flags);
 		pset = per_cpu_ptr(zone->pageset, cpu);
 
 		pcp = &pset->pcp;
-		if (pcp->count) {
-			free_pcppages_bulk(zone, pcp->count, pcp);
+		count = pcp->count;
+		if (count) {
+			isolate_pcp_pages(count, pcp, &dst);
 			pcp->count = 0;
 		}
-		local_irq_restore(flags);
+		cpu_unlock_irqrestore(cpu, flags);
+		if (count)
+			free_pcppages_bulk(zone, count, &dst);
 	}
 }
 
@@ -1341,7 +1386,12 @@
 		else
 			cpumask_clear_cpu(cpu, &cpus_with_pcps);
 	}
+#ifndef CONFIG_PREEMPT_RT_BASE
 	on_each_cpu_mask(&cpus_with_pcps, drain_local_pages, NULL, 1);
+#else
+	for_each_cpu(cpu, &cpus_with_pcps)
+		drain_pages(cpu);
+#endif
 }
 
 #ifdef CONFIG_HIBERNATION
@@ -1397,7 +1447,7 @@
 
 	migratetype = get_pfnblock_migratetype(page, pfn);
 	set_freepage_migratetype(page, migratetype);
-	local_irq_save(flags);
+	local_lock_irqsave(pa_lock, flags);
 	__count_vm_event(PGFREE);
 
 	/*
@@ -1423,12 +1473,17 @@
 	pcp->count++;
 	if (pcp->count >= pcp->high) {
 		unsigned long batch = ACCESS_ONCE(pcp->batch);
-		free_pcppages_bulk(zone, batch, pcp);
+		LIST_HEAD(dst);
+
+		isolate_pcp_pages(batch, pcp, &dst);
 		pcp->count -= batch;
+		local_unlock_irqrestore(pa_lock, flags);
+		free_pcppages_bulk(zone, batch, &dst);
+		return;
 	}
 
 out:
-	local_irq_restore(flags);
+	local_unlock_irqrestore(pa_lock, flags);
 }
 
 /*
@@ -1558,7 +1613,7 @@
 		struct per_cpu_pages *pcp;
 		struct list_head *list;
 
-		local_irq_save(flags);
+		local_lock_irqsave(pa_lock, flags);
 		pcp = &this_cpu_ptr(zone->pageset)->pcp;
 		list = &pcp->lists[migratetype];
 		if (list_empty(list)) {
@@ -1590,13 +1645,15 @@
 			 */
 			WARN_ON_ONCE(order > 1);
 		}
-		spin_lock_irqsave(&zone->lock, flags);
+		local_spin_lock_irqsave(pa_lock, &zone->lock, flags);
 		page = __rmqueue(zone, order, migratetype);
-		spin_unlock(&zone->lock);
-		if (!page)
+		if (!page) {
+			spin_unlock(&zone->lock);
 			goto failed;
+		}
 		__mod_zone_freepage_state(zone, -(1 << order),
 					  get_freepage_migratetype(page));
+		spin_unlock(&zone->lock);
 	}
 
 	__mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
@@ -1606,7 +1663,7 @@
 
 	__count_zone_vm_events(PGALLOC, zone, 1 << order);
 	zone_statistics(preferred_zone, zone, gfp_flags);
-	local_irq_restore(flags);
+	local_unlock_irqrestore(pa_lock, flags);
 
 	VM_BUG_ON_PAGE(bad_range(zone, page), page);
 	if (prep_new_page(page, order, gfp_flags))
@@ -1614,7 +1671,7 @@
 	return page;
 
 failed:
-	local_irq_restore(flags);
+	local_unlock_irqrestore(pa_lock, flags);
 	return NULL;
 }
 
@@ -2325,8 +2382,8 @@
 	count_vm_event(COMPACTSTALL);
 
 	/* Page migration frees to the PCP lists but we want merging */
-	drain_pages(get_cpu());
-	put_cpu();
+	drain_pages(get_cpu_light());
+	put_cpu_light();
 
 	page = get_page_from_freelist(gfp_mask, nodemask,
 			order, zonelist, high_zoneidx,
@@ -5565,6 +5622,7 @@
 void __init page_alloc_init(void)
 {
 	hotcpu_notifier(page_alloc_cpu_notify, 0);
+	local_irq_lock_init(pa_lock);
 }
 
 /*
@@ -6459,7 +6517,7 @@
 	struct per_cpu_pageset *pset;
 
 	/* avoid races with drain_pages()  */
-	local_irq_save(flags);
+	local_lock_irqsave(pa_lock, flags);
 	if (zone->pageset != &boot_pageset) {
 		for_each_online_cpu(cpu) {
 			pset = per_cpu_ptr(zone->pageset, cpu);
@@ -6468,7 +6526,7 @@
 		free_percpu(zone->pageset);
 		zone->pageset = &boot_pageset;
 	}
-	local_irq_restore(flags);
+	local_unlock_irqrestore(pa_lock, flags);
 }
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
diff -Nur linux-3.18.12.orig/mm/slab.h linux-3.18.12/mm/slab.h
--- linux-3.18.12.orig/mm/slab.h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/mm/slab.h	2015-04-26 13:32:22.467684003 -0500
@@ -315,7 +315,11 @@
  * The slab lists for all objects.
  */
 struct kmem_cache_node {
+#ifdef CONFIG_SLUB
+	raw_spinlock_t list_lock;
+#else
 	spinlock_t list_lock;
+#endif
 
 #ifdef CONFIG_SLAB
 	struct list_head slabs_partial;	/* partial list first, better asm code */
diff -Nur linux-3.18.12.orig/mm/slub.c linux-3.18.12/mm/slub.c
--- linux-3.18.12.orig/mm/slub.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/mm/slub.c	2015-04-26 13:32:22.467684003 -0500
@@ -1044,7 +1044,7 @@
 {
 	struct kmem_cache_node *n = get_node(s, page_to_nid(page));
 
-	spin_lock_irqsave(&n->list_lock, *flags);
+	raw_spin_lock_irqsave(&n->list_lock, *flags);
 	slab_lock(page);
 
 	if (!check_slab(s, page))
@@ -1091,7 +1091,7 @@
 
 fail:
 	slab_unlock(page);
-	spin_unlock_irqrestore(&n->list_lock, *flags);
+	raw_spin_unlock_irqrestore(&n->list_lock, *flags);
 	slab_fix(s, "Object at 0x%p not freed", object);
 	return NULL;
 }
@@ -1219,6 +1219,12 @@
 
 #endif /* CONFIG_SLUB_DEBUG */
 
+struct slub_free_list {
+	raw_spinlock_t		lock;
+	struct list_head	list;
+};
+static DEFINE_PER_CPU(struct slub_free_list, slub_free_list);
+
 /*
  * Hooks for other subsystems that check memory allocations. In a typical
  * production configuration these hooks all should produce no code at all.
@@ -1303,10 +1309,15 @@
 	struct page *page;
 	struct kmem_cache_order_objects oo = s->oo;
 	gfp_t alloc_gfp;
+	bool enableirqs;
 
 	flags &= gfp_allowed_mask;
 
-	if (flags & __GFP_WAIT)
+	enableirqs = (flags & __GFP_WAIT) != 0;
+#ifdef CONFIG_PREEMPT_RT_FULL
+	enableirqs |= system_state == SYSTEM_RUNNING;
+#endif
+	if (enableirqs)
 		local_irq_enable();
 
 	flags |= s->allocflags;
@@ -1347,7 +1358,7 @@
 			kmemcheck_mark_unallocated_pages(page, pages);
 	}
 
-	if (flags & __GFP_WAIT)
+	if (enableirqs)
 		local_irq_disable();
 	if (!page)
 		return NULL;
@@ -1365,8 +1376,10 @@
 				void *object)
 {
 	setup_object_debug(s, page, object);
+#ifndef CONFIG_PREEMPT_RT_FULL
 	if (unlikely(s->ctor))
 		s->ctor(object);
+#endif
 }
 
 static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
@@ -1442,6 +1455,16 @@
 	memcg_uncharge_slab(s, order);
 }
 
+static void free_delayed(struct list_head *h)
+{
+	while(!list_empty(h)) {
+		struct page *page = list_first_entry(h, struct page, lru);
+
+		list_del(&page->lru);
+		__free_slab(page->slab_cache, page);
+	}
+}
+
 #define need_reserve_slab_rcu						\
 	(sizeof(((struct page *)NULL)->lru) < sizeof(struct rcu_head))
 
@@ -1476,6 +1499,12 @@
 		}
 
 		call_rcu(head, rcu_free_slab);
+	} else if (irqs_disabled()) {
+		struct slub_free_list *f = &__get_cpu_var(slub_free_list);
+
+		raw_spin_lock(&f->lock);
+		list_add(&page->lru, &f->list);
+		raw_spin_unlock(&f->lock);
 	} else
 		__free_slab(s, page);
 }
@@ -1589,7 +1618,7 @@
 	if (!n || !n->nr_partial)
 		return NULL;
 
-	spin_lock(&n->list_lock);
+	raw_spin_lock(&n->list_lock);
 	list_for_each_entry_safe(page, page2, &n->partial, lru) {
 		void *t;
 
@@ -1614,7 +1643,7 @@
 			break;
 
 	}
-	spin_unlock(&n->list_lock);
+	raw_spin_unlock(&n->list_lock);
 	return object;
 }
 
@@ -1860,7 +1889,7 @@
 			 * that acquire_slab() will see a slab page that
 			 * is frozen
 			 */
-			spin_lock(&n->list_lock);
+			raw_spin_lock(&n->list_lock);
 		}
 	} else {
 		m = M_FULL;
@@ -1871,7 +1900,7 @@
 			 * slabs from diagnostic functions will not see
 			 * any frozen slabs.
 			 */
-			spin_lock(&n->list_lock);
+			raw_spin_lock(&n->list_lock);
 		}
 	}
 
@@ -1906,7 +1935,7 @@
 		goto redo;
 
 	if (lock)
-		spin_unlock(&n->list_lock);
+		raw_spin_unlock(&n->list_lock);
 
 	if (m == M_FREE) {
 		stat(s, DEACTIVATE_EMPTY);
@@ -1938,10 +1967,10 @@
 		n2 = get_node(s, page_to_nid(page));
 		if (n != n2) {
 			if (n)
-				spin_unlock(&n->list_lock);
+				raw_spin_unlock(&n->list_lock);
 
 			n = n2;
-			spin_lock(&n->list_lock);
+			raw_spin_lock(&n->list_lock);
 		}
 
 		do {
@@ -1970,7 +1999,7 @@
 	}
 
 	if (n)
-		spin_unlock(&n->list_lock);
+		raw_spin_unlock(&n->list_lock);
 
 	while (discard_page) {
 		page = discard_page;
@@ -2008,14 +2037,21 @@
 			pobjects = oldpage->pobjects;
 			pages = oldpage->pages;
 			if (drain && pobjects > s->cpu_partial) {
+				struct slub_free_list *f;
 				unsigned long flags;
+				LIST_HEAD(tofree);
 				/*
 				 * partial array is full. Move the existing
 				 * set to the per node partial list.
 				 */
 				local_irq_save(flags);
 				unfreeze_partials(s, this_cpu_ptr(s->cpu_slab));
+				f = &__get_cpu_var(slub_free_list);
+				raw_spin_lock(&f->lock);
+				list_splice_init(&f->list, &tofree);
+				raw_spin_unlock(&f->lock);
 				local_irq_restore(flags);
+				free_delayed(&tofree);
 				oldpage = NULL;
 				pobjects = 0;
 				pages = 0;
@@ -2079,7 +2115,22 @@
 
 static void flush_all(struct kmem_cache *s)
 {
+	LIST_HEAD(tofree);
+	int cpu;
+
 	on_each_cpu_cond(has_cpu_slab, flush_cpu_slab, s, 1, GFP_ATOMIC);
+	for_each_online_cpu(cpu) {
+		struct slub_free_list *f;
+
+		if (!has_cpu_slab(cpu, s))
+			continue;
+
+		f = &per_cpu(slub_free_list, cpu);
+		raw_spin_lock_irq(&f->lock);
+		list_splice_init(&f->list, &tofree);
+		raw_spin_unlock_irq(&f->lock);
+		free_delayed(&tofree);
+	}
 }
 
 /*
@@ -2115,10 +2166,10 @@
 	unsigned long x = 0;
 	struct page *page;
 
-	spin_lock_irqsave(&n->list_lock, flags);
+	raw_spin_lock_irqsave(&n->list_lock, flags);
 	list_for_each_entry(page, &n->partial, lru)
 		x += get_count(page);
-	spin_unlock_irqrestore(&n->list_lock, flags);
+	raw_spin_unlock_irqrestore(&n->list_lock, flags);
 	return x;
 }
 #endif /* CONFIG_SLUB_DEBUG || CONFIG_SYSFS */
@@ -2255,9 +2306,11 @@
 static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
 			  unsigned long addr, struct kmem_cache_cpu *c)
 {
+	struct slub_free_list *f;
 	void *freelist;
 	struct page *page;
 	unsigned long flags;
+	LIST_HEAD(tofree);
 
 	local_irq_save(flags);
 #ifdef CONFIG_PREEMPT
@@ -2325,7 +2378,13 @@
 	VM_BUG_ON(!c->page->frozen);
 	c->freelist = get_freepointer(s, freelist);
 	c->tid = next_tid(c->tid);
+out:
+	f = &__get_cpu_var(slub_free_list);
+	raw_spin_lock(&f->lock);
+	list_splice_init(&f->list, &tofree);
+	raw_spin_unlock(&f->lock);
 	local_irq_restore(flags);
+	free_delayed(&tofree);
 	return freelist;
 
 new_slab:
@@ -2342,8 +2401,7 @@
 
 	if (unlikely(!freelist)) {
 		slab_out_of_memory(s, gfpflags, node);
-		local_irq_restore(flags);
-		return NULL;
+		goto out;
 	}
 
 	page = c->page;
@@ -2358,8 +2416,7 @@
 	deactivate_slab(s, page, get_freepointer(s, freelist));
 	c->page = NULL;
 	c->freelist = NULL;
-	local_irq_restore(flags);
-	return freelist;
+	goto out;
 }
 
 /*
@@ -2444,6 +2501,10 @@
 
 	if (unlikely(gfpflags & __GFP_ZERO) && object)
 		memset(object, 0, s->object_size);
+#ifdef CONFIG_PREEMPT_RT_FULL
+	if (unlikely(s->ctor) && object)
+		s->ctor(object);
+#endif
 
 	slab_post_alloc_hook(s, gfpflags, object);
 
@@ -2531,7 +2592,7 @@
 
 	do {
 		if (unlikely(n)) {
-			spin_unlock_irqrestore(&n->list_lock, flags);
+			raw_spin_unlock_irqrestore(&n->list_lock, flags);
 			n = NULL;
 		}
 		prior = page->freelist;
@@ -2563,7 +2624,7 @@
 				 * Otherwise the list_lock will synchronize with
 				 * other processors updating the list of slabs.
 				 */
-				spin_lock_irqsave(&n->list_lock, flags);
+				raw_spin_lock_irqsave(&n->list_lock, flags);
 
 			}
 		}
@@ -2605,7 +2666,7 @@
 		add_partial(n, page, DEACTIVATE_TO_TAIL);
 		stat(s, FREE_ADD_PARTIAL);
 	}
-	spin_unlock_irqrestore(&n->list_lock, flags);
+	raw_spin_unlock_irqrestore(&n->list_lock, flags);
 	return;
 
 slab_empty:
@@ -2620,7 +2681,7 @@
 		remove_full(s, n, page);
 	}
 
-	spin_unlock_irqrestore(&n->list_lock, flags);
+	raw_spin_unlock_irqrestore(&n->list_lock, flags);
 	stat(s, FREE_SLAB);
 	discard_slab(s, page);
 }
@@ -2816,7 +2877,7 @@
 init_kmem_cache_node(struct kmem_cache_node *n)
 {
 	n->nr_partial = 0;
-	spin_lock_init(&n->list_lock);
+	raw_spin_lock_init(&n->list_lock);
 	INIT_LIST_HEAD(&n->partial);
 #ifdef CONFIG_SLUB_DEBUG
 	atomic_long_set(&n->nr_slabs, 0);
@@ -3373,7 +3434,7 @@
 		for (i = 0; i < objects; i++)
 			INIT_LIST_HEAD(slabs_by_inuse + i);
 
-		spin_lock_irqsave(&n->list_lock, flags);
+		raw_spin_lock_irqsave(&n->list_lock, flags);
 
 		/*
 		 * Build lists indexed by the items in use in each slab.
@@ -3394,7 +3455,7 @@
 		for (i = objects - 1; i > 0; i--)
 			list_splice(slabs_by_inuse + i, n->partial.prev);
 
-		spin_unlock_irqrestore(&n->list_lock, flags);
+		raw_spin_unlock_irqrestore(&n->list_lock, flags);
 
 		/* Release empty slabs */
 		list_for_each_entry_safe(page, t, slabs_by_inuse, lru)
@@ -3567,6 +3628,12 @@
 {
 	static __initdata struct kmem_cache boot_kmem_cache,
 		boot_kmem_cache_node;
+	int cpu;
+
+	for_each_possible_cpu(cpu) {
+		raw_spin_lock_init(&per_cpu(slub_free_list, cpu).lock);
+		INIT_LIST_HEAD(&per_cpu(slub_free_list, cpu).list);
+	}
 
 	if (debug_guardpage_minorder())
 		slub_max_order = 0;
@@ -3815,7 +3882,7 @@
 	struct page *page;
 	unsigned long flags;
 
-	spin_lock_irqsave(&n->list_lock, flags);
+	raw_spin_lock_irqsave(&n->list_lock, flags);
 
 	list_for_each_entry(page, &n->partial, lru) {
 		validate_slab_slab(s, page, map);
@@ -3837,7 +3904,7 @@
 		       s->name, count, atomic_long_read(&n->nr_slabs));
 
 out:
-	spin_unlock_irqrestore(&n->list_lock, flags);
+	raw_spin_unlock_irqrestore(&n->list_lock, flags);
 	return count;
 }
 
@@ -4025,12 +4092,12 @@
 		if (!atomic_long_read(&n->nr_slabs))
 			continue;
 
-		spin_lock_irqsave(&n->list_lock, flags);
+		raw_spin_lock_irqsave(&n->list_lock, flags);
 		list_for_each_entry(page, &n->partial, lru)
 			process_slab(&t, s, page, alloc, map);
 		list_for_each_entry(page, &n->full, lru)
 			process_slab(&t, s, page, alloc, map);
-		spin_unlock_irqrestore(&n->list_lock, flags);
+		raw_spin_unlock_irqrestore(&n->list_lock, flags);
 	}
 
 	for (i = 0; i < t.count; i++) {
diff -Nur linux-3.18.12.orig/mm/swap.c linux-3.18.12/mm/swap.c
--- linux-3.18.12.orig/mm/swap.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/mm/swap.c	2015-04-26 13:32:22.467684003 -0500
@@ -31,6 +31,7 @@
 #include <linux/memcontrol.h>
 #include <linux/gfp.h>
 #include <linux/uio.h>
+#include <linux/locallock.h>
 
 #include "internal.h"
 
@@ -44,6 +45,9 @@
 static DEFINE_PER_CPU(struct pagevec, lru_rotate_pvecs);
 static DEFINE_PER_CPU(struct pagevec, lru_deactivate_pvecs);
 
+static DEFINE_LOCAL_IRQ_LOCK(rotate_lock);
+static DEFINE_LOCAL_IRQ_LOCK(swapvec_lock);
+
 /*
  * This path almost never happens for VM activity - pages are normally
  * freed via pagevecs.  But it gets used by networking.
@@ -473,11 +477,11 @@
 		unsigned long flags;
 
 		page_cache_get(page);
-		local_irq_save(flags);
+		local_lock_irqsave(rotate_lock, flags);
 		pvec = this_cpu_ptr(&lru_rotate_pvecs);
 		if (!pagevec_add(pvec, page))
 			pagevec_move_tail(pvec);
-		local_irq_restore(flags);
+		local_unlock_irqrestore(rotate_lock, flags);
 	}
 }
 
@@ -528,12 +532,13 @@
 void activate_page(struct page *page)
 {
 	if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
-		struct pagevec *pvec = &get_cpu_var(activate_page_pvecs);
+		struct pagevec *pvec = &get_locked_var(swapvec_lock,
+						       activate_page_pvecs);
 
 		page_cache_get(page);
 		if (!pagevec_add(pvec, page))
 			pagevec_lru_move_fn(pvec, __activate_page, NULL);
-		put_cpu_var(activate_page_pvecs);
+		put_locked_var(swapvec_lock, activate_page_pvecs);
 	}
 }
 
@@ -559,7 +564,7 @@
 
 static void __lru_cache_activate_page(struct page *page)
 {
-	struct pagevec *pvec = &get_cpu_var(lru_add_pvec);
+	struct pagevec *pvec = &get_locked_var(swapvec_lock, lru_add_pvec);
 	int i;
 
 	/*
@@ -581,7 +586,7 @@
 		}
 	}
 
-	put_cpu_var(lru_add_pvec);
+	put_locked_var(swapvec_lock, lru_add_pvec);
 }
 
 /*
@@ -620,13 +625,13 @@
 
 static void __lru_cache_add(struct page *page)
 {
-	struct pagevec *pvec = &get_cpu_var(lru_add_pvec);
+	struct pagevec *pvec = &get_locked_var(swapvec_lock, lru_add_pvec);
 
 	page_cache_get(page);
 	if (!pagevec_space(pvec))
 		__pagevec_lru_add(pvec);
 	pagevec_add(pvec, page);
-	put_cpu_var(lru_add_pvec);
+	put_locked_var(swapvec_lock, lru_add_pvec);
 }
 
 /**
@@ -806,9 +811,9 @@
 		unsigned long flags;
 
 		/* No harm done if a racing interrupt already did this */
-		local_irq_save(flags);
+		local_lock_irqsave(rotate_lock, flags);
 		pagevec_move_tail(pvec);
-		local_irq_restore(flags);
+		local_unlock_irqrestore(rotate_lock, flags);
 	}
 
 	pvec = &per_cpu(lru_deactivate_pvecs, cpu);
@@ -836,18 +841,19 @@
 		return;
 
 	if (likely(get_page_unless_zero(page))) {
-		struct pagevec *pvec = &get_cpu_var(lru_deactivate_pvecs);
+		struct pagevec *pvec = &get_locked_var(swapvec_lock,
+						       lru_deactivate_pvecs);
 
 		if (!pagevec_add(pvec, page))
 			pagevec_lru_move_fn(pvec, lru_deactivate_fn, NULL);
-		put_cpu_var(lru_deactivate_pvecs);
+		put_locked_var(swapvec_lock, lru_deactivate_pvecs);
 	}
 }
 
 void lru_add_drain(void)
 {
-	lru_add_drain_cpu(get_cpu());
-	put_cpu();
+	lru_add_drain_cpu(local_lock_cpu(swapvec_lock));
+	local_unlock_cpu(swapvec_lock);
 }
 
 static void lru_add_drain_per_cpu(struct work_struct *dummy)
diff -Nur linux-3.18.12.orig/mm/truncate.c linux-3.18.12/mm/truncate.c
--- linux-3.18.12.orig/mm/truncate.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/mm/truncate.c	2015-04-26 13:32:22.467684003 -0500
@@ -56,8 +56,11 @@
 	 * protected by mapping->tree_lock.
 	 */
 	if (!workingset_node_shadows(node) &&
-	    !list_empty(&node->private_list))
-		list_lru_del(&workingset_shadow_nodes, &node->private_list);
+	    !list_empty(&node->private_list)) {
+		local_lock(workingset_shadow_lock);
+		list_lru_del(&__workingset_shadow_nodes, &node->private_list);
+		local_unlock(workingset_shadow_lock);
+	}
 	__radix_tree_delete_node(&mapping->page_tree, node);
 unlock:
 	spin_unlock_irq(&mapping->tree_lock);
diff -Nur linux-3.18.12.orig/mm/vmalloc.c linux-3.18.12/mm/vmalloc.c
--- linux-3.18.12.orig/mm/vmalloc.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/mm/vmalloc.c	2015-04-26 13:32:22.467684003 -0500
@@ -798,7 +798,7 @@
 	struct vmap_block *vb;
 	struct vmap_area *va;
 	unsigned long vb_idx;
-	int node, err;
+	int node, err, cpu;
 
 	node = numa_node_id();
 
@@ -836,11 +836,12 @@
 	BUG_ON(err);
 	radix_tree_preload_end();
 
-	vbq = &get_cpu_var(vmap_block_queue);
+	cpu = get_cpu_light();
+	vbq = &__get_cpu_var(vmap_block_queue);
 	spin_lock(&vbq->lock);
 	list_add_rcu(&vb->free_list, &vbq->free);
 	spin_unlock(&vbq->lock);
-	put_cpu_var(vmap_block_queue);
+	put_cpu_light();
 
 	return vb;
 }
@@ -908,6 +909,7 @@
 	struct vmap_block *vb;
 	unsigned long addr = 0;
 	unsigned int order;
+	int cpu = 0;
 
 	BUG_ON(size & ~PAGE_MASK);
 	BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
@@ -923,7 +925,8 @@
 
 again:
 	rcu_read_lock();
-	vbq = &get_cpu_var(vmap_block_queue);
+	cpu = get_cpu_light();
+	vbq = &__get_cpu_var(vmap_block_queue);
 	list_for_each_entry_rcu(vb, &vbq->free, free_list) {
 		int i;
 
@@ -947,7 +950,7 @@
 		spin_unlock(&vb->lock);
 	}
 
-	put_cpu_var(vmap_block_queue);
+	put_cpu_light();
 	rcu_read_unlock();
 
 	if (!addr) {
diff -Nur linux-3.18.12.orig/mm/vmstat.c linux-3.18.12/mm/vmstat.c
--- linux-3.18.12.orig/mm/vmstat.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/mm/vmstat.c	2015-04-26 13:32:22.467684003 -0500
@@ -221,6 +221,7 @@
 	long x;
 	long t;
 
+	preempt_disable_rt();
 	x = delta + __this_cpu_read(*p);
 
 	t = __this_cpu_read(pcp->stat_threshold);
@@ -230,6 +231,7 @@
 		x = 0;
 	}
 	__this_cpu_write(*p, x);
+	preempt_enable_rt();
 }
 EXPORT_SYMBOL(__mod_zone_page_state);
 
@@ -262,6 +264,7 @@
 	s8 __percpu *p = pcp->vm_stat_diff + item;
 	s8 v, t;
 
+	preempt_disable_rt();
 	v = __this_cpu_inc_return(*p);
 	t = __this_cpu_read(pcp->stat_threshold);
 	if (unlikely(v > t)) {
@@ -270,6 +273,7 @@
 		zone_page_state_add(v + overstep, zone, item);
 		__this_cpu_write(*p, -overstep);
 	}
+	preempt_enable_rt();
 }
 
 void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
@@ -284,6 +288,7 @@
 	s8 __percpu *p = pcp->vm_stat_diff + item;
 	s8 v, t;
 
+	preempt_disable_rt();
 	v = __this_cpu_dec_return(*p);
 	t = __this_cpu_read(pcp->stat_threshold);
 	if (unlikely(v < - t)) {
@@ -292,6 +297,7 @@
 		zone_page_state_add(v - overstep, zone, item);
 		__this_cpu_write(*p, overstep);
 	}
+	preempt_enable_rt();
 }
 
 void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
diff -Nur linux-3.18.12.orig/mm/workingset.c linux-3.18.12/mm/workingset.c
--- linux-3.18.12.orig/mm/workingset.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/mm/workingset.c	2015-04-26 13:32:22.467684003 -0500
@@ -264,7 +264,8 @@
  * point where they would still be useful.
  */
 
-struct list_lru workingset_shadow_nodes;
+struct list_lru __workingset_shadow_nodes;
+DEFINE_LOCAL_IRQ_LOCK(workingset_shadow_lock);
 
 static unsigned long count_shadow_nodes(struct shrinker *shrinker,
 					struct shrink_control *sc)
@@ -274,9 +275,9 @@
 	unsigned long pages;
 
 	/* list_lru lock nests inside IRQ-safe mapping->tree_lock */
-	local_irq_disable();
-	shadow_nodes = list_lru_count_node(&workingset_shadow_nodes, sc->nid);
-	local_irq_enable();
+	local_lock_irq(workingset_shadow_lock);
+	shadow_nodes = list_lru_count_node(&__workingset_shadow_nodes, sc->nid);
+	local_unlock_irq(workingset_shadow_lock);
 
 	pages = node_present_pages(sc->nid);
 	/*
@@ -362,9 +363,9 @@
 	spin_unlock(&mapping->tree_lock);
 	ret = LRU_REMOVED_RETRY;
 out:
-	local_irq_enable();
+	local_unlock_irq(workingset_shadow_lock);
 	cond_resched();
-	local_irq_disable();
+	local_lock_irq(workingset_shadow_lock);
 	spin_lock(lru_lock);
 	return ret;
 }
@@ -375,10 +376,10 @@
 	unsigned long ret;
 
 	/* list_lru lock nests inside IRQ-safe mapping->tree_lock */
-	local_irq_disable();
-	ret =  list_lru_walk_node(&workingset_shadow_nodes, sc->nid,
+	local_lock_irq(workingset_shadow_lock);
+	ret =  list_lru_walk_node(&__workingset_shadow_nodes, sc->nid,
 				  shadow_lru_isolate, NULL, &sc->nr_to_scan);
-	local_irq_enable();
+	local_unlock_irq(workingset_shadow_lock);
 	return ret;
 }
 
@@ -399,7 +400,7 @@
 {
 	int ret;
 
-	ret = list_lru_init_key(&workingset_shadow_nodes, &shadow_nodes_key);
+	ret = list_lru_init_key(&__workingset_shadow_nodes, &shadow_nodes_key);
 	if (ret)
 		goto err;
 	ret = register_shrinker(&workingset_shadow_shrinker);
@@ -407,7 +408,7 @@
 		goto err_list_lru;
 	return 0;
 err_list_lru:
-	list_lru_destroy(&workingset_shadow_nodes);
+	list_lru_destroy(&__workingset_shadow_nodes);
 err:
 	return ret;
 }
diff -Nur linux-3.18.12.orig/net/core/dev.c linux-3.18.12/net/core/dev.c
--- linux-3.18.12.orig/net/core/dev.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/net/core/dev.c	2015-04-26 13:32:22.471684003 -0500
@@ -182,6 +182,7 @@
 static DEFINE_HASHTABLE(napi_hash, 8);
 
 static seqcount_t devnet_rename_seq;
+static DEFINE_MUTEX(devnet_rename_mutex);
 
 static inline void dev_base_seq_inc(struct net *net)
 {
@@ -203,14 +204,14 @@
 static inline void rps_lock(struct softnet_data *sd)
 {
 #ifdef CONFIG_RPS
-	spin_lock(&sd->input_pkt_queue.lock);
+	raw_spin_lock(&sd->input_pkt_queue.raw_lock);
 #endif
 }
 
 static inline void rps_unlock(struct softnet_data *sd)
 {
 #ifdef CONFIG_RPS
-	spin_unlock(&sd->input_pkt_queue.lock);
+	raw_spin_unlock(&sd->input_pkt_queue.raw_lock);
 #endif
 }
 
@@ -832,7 +833,8 @@
 	strcpy(name, dev->name);
 	rcu_read_unlock();
 	if (read_seqcount_retry(&devnet_rename_seq, seq)) {
-		cond_resched();
+		mutex_lock(&devnet_rename_mutex);
+		mutex_unlock(&devnet_rename_mutex);
 		goto retry;
 	}
 
@@ -1101,20 +1103,17 @@
 	if (dev->flags & IFF_UP)
 		return -EBUSY;
 
-	write_seqcount_begin(&devnet_rename_seq);
+	mutex_lock(&devnet_rename_mutex);
+	__raw_write_seqcount_begin(&devnet_rename_seq);
 
-	if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
-		write_seqcount_end(&devnet_rename_seq);
-		return 0;
-	}
+	if (strncmp(newname, dev->name, IFNAMSIZ) == 0)
+		goto outunlock;
 
 	memcpy(oldname, dev->name, IFNAMSIZ);
 
 	err = dev_get_valid_name(net, dev, newname);
-	if (err < 0) {
-		write_seqcount_end(&devnet_rename_seq);
-		return err;
-	}
+	if (err < 0)
+		goto outunlock;
 
 	if (oldname[0] && !strchr(oldname, '%'))
 		netdev_info(dev, "renamed from %s\n", oldname);
@@ -1127,11 +1126,12 @@
 	if (ret) {
 		memcpy(dev->name, oldname, IFNAMSIZ);
 		dev->name_assign_type = old_assign_type;
-		write_seqcount_end(&devnet_rename_seq);
-		return ret;
+		err = ret;
+		goto outunlock;
 	}
 
-	write_seqcount_end(&devnet_rename_seq);
+	__raw_write_seqcount_end(&devnet_rename_seq);
+	mutex_unlock(&devnet_rename_mutex);
 
 	netdev_adjacent_rename_links(dev, oldname);
 
@@ -1152,7 +1152,8 @@
 		/* err >= 0 after dev_alloc_name() or stores the first errno */
 		if (err >= 0) {
 			err = ret;
-			write_seqcount_begin(&devnet_rename_seq);
+			mutex_lock(&devnet_rename_mutex);
+			__raw_write_seqcount_begin(&devnet_rename_seq);
 			memcpy(dev->name, oldname, IFNAMSIZ);
 			memcpy(oldname, newname, IFNAMSIZ);
 			dev->name_assign_type = old_assign_type;
@@ -1165,6 +1166,11 @@
 	}
 
 	return err;
+
+outunlock:
+	__raw_write_seqcount_end(&devnet_rename_seq);
+	mutex_unlock(&devnet_rename_mutex);
+	return err;
 }
 
 /**
@@ -2160,6 +2166,7 @@
 	sd->output_queue_tailp = &q->next_sched;
 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
 	local_irq_restore(flags);
+	preempt_check_resched_rt();
 }
 
 void __netif_schedule(struct Qdisc *q)
@@ -2241,6 +2248,7 @@
 	__this_cpu_write(softnet_data.completion_queue, skb);
 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
 	local_irq_restore(flags);
+	preempt_check_resched_rt();
 }
 EXPORT_SYMBOL(__dev_kfree_skb_irq);
 
@@ -3336,6 +3344,7 @@
 	rps_unlock(sd);
 
 	local_irq_restore(flags);
+	preempt_check_resched_rt();
 
 	atomic_long_inc(&skb->dev->rx_dropped);
 	kfree_skb(skb);
@@ -3354,7 +3363,7 @@
 		struct rps_dev_flow voidflow, *rflow = &voidflow;
 		int cpu;
 
-		preempt_disable();
+		migrate_disable();
 		rcu_read_lock();
 
 		cpu = get_rps_cpu(skb->dev, skb, &rflow);
@@ -3364,13 +3373,13 @@
 		ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
 
 		rcu_read_unlock();
-		preempt_enable();
+		migrate_enable();
 	} else
 #endif
 	{
 		unsigned int qtail;
-		ret = enqueue_to_backlog(skb, get_cpu(), &qtail);
-		put_cpu();
+		ret = enqueue_to_backlog(skb, get_cpu_light(), &qtail);
+		put_cpu_light();
 	}
 	return ret;
 }
@@ -3404,16 +3413,44 @@
 
 	trace_netif_rx_ni_entry(skb);
 
-	preempt_disable();
+	local_bh_disable();
 	err = netif_rx_internal(skb);
-	if (local_softirq_pending())
-		do_softirq();
-	preempt_enable();
+	local_bh_enable();
 
 	return err;
 }
 EXPORT_SYMBOL(netif_rx_ni);
 
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * RT runs ksoftirqd as a real time thread and the root_lock is a
+ * "sleeping spinlock". If the trylock fails then we can go into an
+ * infinite loop when ksoftirqd preempted the task which actually
+ * holds the lock, because we requeue q and raise NET_TX softirq
+ * causing ksoftirqd to loop forever.
+ *
+ * It's safe to use spin_lock on RT here as softirqs run in thread
+ * context and cannot deadlock against the thread which is holding
+ * root_lock.
+ *
+ * On !RT the trylock might fail, but there we bail out from the
+ * softirq loop after 10 attempts which we can't do on RT. And the
+ * task holding root_lock cannot be preempted, so the only downside of
+ * that trylock is that we need 10 loops to decide that we should have
+ * given up in the first one :)
+ */
+static inline int take_root_lock(spinlock_t *lock)
+{
+	spin_lock(lock);
+	return 1;
+}
+#else
+static inline int take_root_lock(spinlock_t *lock)
+{
+	return spin_trylock(lock);
+}
+#endif
+
 static void net_tx_action(struct softirq_action *h)
 {
 	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
@@ -3455,7 +3492,7 @@
 			head = head->next_sched;
 
 			root_lock = qdisc_lock(q);
-			if (spin_trylock(root_lock)) {
+			if (take_root_lock(root_lock)) {
 				smp_mb__before_atomic();
 				clear_bit(__QDISC_STATE_SCHED,
 					  &q->state);
@@ -3848,7 +3885,7 @@
 	skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
 		if (skb->dev == dev) {
 			__skb_unlink(skb, &sd->input_pkt_queue);
-			kfree_skb(skb);
+			__skb_queue_tail(&sd->tofree_queue, skb);
 			input_queue_head_incr(sd);
 		}
 	}
@@ -3857,10 +3894,13 @@
 	skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
 		if (skb->dev == dev) {
 			__skb_unlink(skb, &sd->process_queue);
-			kfree_skb(skb);
+			__skb_queue_tail(&sd->tofree_queue, skb);
 			input_queue_head_incr(sd);
 		}
 	}
+
+	if (!skb_queue_empty(&sd->tofree_queue))
+		raise_softirq_irqoff(NET_RX_SOFTIRQ);
 }
 
 static int napi_gro_complete(struct sk_buff *skb)
@@ -4323,6 +4363,7 @@
 	} else
 #endif
 		local_irq_enable();
+	preempt_check_resched_rt();
 }
 
 static int process_backlog(struct napi_struct *napi, int quota)
@@ -4394,6 +4435,7 @@
 	local_irq_save(flags);
 	____napi_schedule(this_cpu_ptr(&softnet_data), n);
 	local_irq_restore(flags);
+	preempt_check_resched_rt();
 }
 EXPORT_SYMBOL(__napi_schedule);
 
@@ -4516,10 +4558,17 @@
 	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
 	unsigned long time_limit = jiffies + 2;
 	int budget = netdev_budget;
+	struct sk_buff *skb;
 	void *have;
 
 	local_irq_disable();
 
+	while ((skb = __skb_dequeue(&sd->tofree_queue))) {
+		local_irq_enable();
+		kfree_skb(skb);
+		local_irq_disable();
+	}
+
 	while (!list_empty(&sd->poll_list)) {
 		struct napi_struct *n;
 		int work, weight;
@@ -7008,6 +7057,7 @@
 
 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
 	local_irq_enable();
+	preempt_check_resched_rt();
 
 	/* Process offline CPU's input_pkt_queue */
 	while ((skb = __skb_dequeue(&oldsd->process_queue))) {
@@ -7018,6 +7068,9 @@
 		netif_rx_internal(skb);
 		input_queue_head_incr(oldsd);
 	}
+	while ((skb = __skb_dequeue(&oldsd->tofree_queue))) {
+		kfree_skb(skb);
+	}
 
 	return NOTIFY_OK;
 }
@@ -7319,8 +7372,9 @@
 	for_each_possible_cpu(i) {
 		struct softnet_data *sd = &per_cpu(softnet_data, i);
 
-		skb_queue_head_init(&sd->input_pkt_queue);
-		skb_queue_head_init(&sd->process_queue);
+		skb_queue_head_init_raw(&sd->input_pkt_queue);
+		skb_queue_head_init_raw(&sd->process_queue);
+		skb_queue_head_init_raw(&sd->tofree_queue);
 		INIT_LIST_HEAD(&sd->poll_list);
 		sd->output_queue_tailp = &sd->output_queue;
 #ifdef CONFIG_RPS
diff -Nur linux-3.18.12.orig/net/core/skbuff.c linux-3.18.12/net/core/skbuff.c
--- linux-3.18.12.orig/net/core/skbuff.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/net/core/skbuff.c	2015-04-26 13:32:22.471684003 -0500
@@ -63,6 +63,7 @@
 #include <linux/errqueue.h>
 #include <linux/prefetch.h>
 #include <linux/if_vlan.h>
+#include <linux/locallock.h>
 
 #include <net/protocol.h>
 #include <net/dst.h>
@@ -336,6 +337,7 @@
 	unsigned int		pagecnt_bias;
 };
 static DEFINE_PER_CPU(struct netdev_alloc_cache, netdev_alloc_cache);
+static DEFINE_LOCAL_IRQ_LOCK(netdev_alloc_lock);
 
 static void *__netdev_alloc_frag(unsigned int fragsz, gfp_t gfp_mask)
 {
@@ -344,7 +346,7 @@
 	int order;
 	unsigned long flags;
 
-	local_irq_save(flags);
+	local_lock_irqsave(netdev_alloc_lock, flags);
 	nc = this_cpu_ptr(&netdev_alloc_cache);
 	if (unlikely(!nc->frag.page)) {
 refill:
@@ -389,7 +391,7 @@
 	nc->frag.offset += fragsz;
 	nc->pagecnt_bias--;
 end:
-	local_irq_restore(flags);
+	local_unlock_irqrestore(netdev_alloc_lock, flags);
 	return data;
 }
 
diff -Nur linux-3.18.12.orig/net/core/sock.c linux-3.18.12/net/core/sock.c
--- linux-3.18.12.orig/net/core/sock.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/net/core/sock.c	2015-04-26 13:32:22.471684003 -0500
@@ -2326,12 +2326,11 @@
 	if (sk->sk_lock.owned)
 		__lock_sock(sk);
 	sk->sk_lock.owned = 1;
-	spin_unlock(&sk->sk_lock.slock);
+	spin_unlock_bh(&sk->sk_lock.slock);
 	/*
 	 * The sk_lock has mutex_lock() semantics here:
 	 */
 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
-	local_bh_enable();
 }
 EXPORT_SYMBOL(lock_sock_nested);
 
diff -Nur linux-3.18.12.orig/net/ipv4/icmp.c linux-3.18.12/net/ipv4/icmp.c
--- linux-3.18.12.orig/net/ipv4/icmp.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/net/ipv4/icmp.c	2015-04-26 13:32:22.471684003 -0500
@@ -69,6 +69,7 @@
 #include <linux/jiffies.h>
 #include <linux/kernel.h>
 #include <linux/fcntl.h>
+#include <linux/sysrq.h>
 #include <linux/socket.h>
 #include <linux/in.h>
 #include <linux/inet.h>
@@ -864,6 +865,30 @@
 }
 
 /*
+ * 32bit and 64bit have different timestamp length, so we check for
+ * the cookie at offset 20 and verify it is repeated at offset 50
+ */
+#define CO_POS0		20
+#define CO_POS1		50
+#define CO_SIZE		sizeof(int)
+#define ICMP_SYSRQ_SIZE	57
+
+/*
+ * We got a ICMP_SYSRQ_SIZE sized ping request. Check for the cookie
+ * pattern and if it matches send the next byte as a trigger to sysrq.
+ */
+static void icmp_check_sysrq(struct net *net, struct sk_buff *skb)
+{
+	int cookie = htonl(net->ipv4.sysctl_icmp_echo_sysrq);
+	char *p = skb->data;
+
+	if (!memcmp(&cookie, p + CO_POS0, CO_SIZE) &&
+	    !memcmp(&cookie, p + CO_POS1, CO_SIZE) &&
+	    p[CO_POS0 + CO_SIZE] == p[CO_POS1 + CO_SIZE])
+		handle_sysrq(p[CO_POS0 + CO_SIZE]);
+}
+
+/*
  *	Handle ICMP_ECHO ("ping") requests.
  *
  *	RFC 1122: 3.2.2.6 MUST have an echo server that answers ICMP echo
@@ -890,6 +915,11 @@
 		icmp_param.data_len	   = skb->len;
 		icmp_param.head_len	   = sizeof(struct icmphdr);
 		icmp_reply(&icmp_param, skb);
+
+		if (skb->len == ICMP_SYSRQ_SIZE &&
+		    net->ipv4.sysctl_icmp_echo_sysrq) {
+			icmp_check_sysrq(net, skb);
+		}
 	}
 }
 
diff -Nur linux-3.18.12.orig/net/ipv4/sysctl_net_ipv4.c linux-3.18.12/net/ipv4/sysctl_net_ipv4.c
--- linux-3.18.12.orig/net/ipv4/sysctl_net_ipv4.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/net/ipv4/sysctl_net_ipv4.c	2015-04-26 13:32:22.471684003 -0500
@@ -779,6 +779,13 @@
 		.proc_handler	= proc_dointvec
 	},
 	{
+		.procname	= "icmp_echo_sysrq",
+		.data		= &init_net.ipv4.sysctl_icmp_echo_sysrq,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec
+	},
+	{
 		.procname	= "icmp_ignore_bogus_error_responses",
 		.data		= &init_net.ipv4.sysctl_icmp_ignore_bogus_error_responses,
 		.maxlen		= sizeof(int),
diff -Nur linux-3.18.12.orig/net/mac80211/rx.c linux-3.18.12/net/mac80211/rx.c
--- linux-3.18.12.orig/net/mac80211/rx.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/net/mac80211/rx.c	2015-04-26 13:32:22.471684003 -0500
@@ -3359,7 +3359,7 @@
 	struct ieee80211_supported_band *sband;
 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 
-	WARN_ON_ONCE(softirq_count() == 0);
+	WARN_ON_ONCE_NONRT(softirq_count() == 0);
 
 	if (WARN_ON(status->band >= IEEE80211_NUM_BANDS))
 		goto drop;
diff -Nur linux-3.18.12.orig/net/mac80211/rx.c.orig linux-3.18.12/net/mac80211/rx.c.orig
--- linux-3.18.12.orig/net/mac80211/rx.c.orig	1969-12-31 18:00:00.000000000 -0600
+++ linux-3.18.12/net/mac80211/rx.c.orig	2015-04-20 14:48:02.000000000 -0500
@@ -0,0 +1,3476 @@
+/*
+ * Copyright 2002-2005, Instant802 Networks, Inc.
+ * Copyright 2005-2006, Devicescape Software, Inc.
+ * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
+ * Copyright 2007-2010	Johannes Berg <johannes@sipsolutions.net>
+ * Copyright 2013-2014  Intel Mobile Communications GmbH
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/jiffies.h>
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/rcupdate.h>
+#include <linux/export.h>
+#include <net/mac80211.h>
+#include <net/ieee80211_radiotap.h>
+#include <asm/unaligned.h>
+
+#include "ieee80211_i.h"
+#include "driver-ops.h"
+#include "led.h"
+#include "mesh.h"
+#include "wep.h"
+#include "wpa.h"
+#include "tkip.h"
+#include "wme.h"
+#include "rate.h"
+
+/*
+ * monitor mode reception
+ *
+ * This function cleans up the SKB, i.e. it removes all the stuff
+ * only useful for monitoring.
+ */
+static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
+					   struct sk_buff *skb)
+{
+	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
+		if (likely(skb->len > FCS_LEN))
+			__pskb_trim(skb, skb->len - FCS_LEN);
+		else {
+			/* driver bug */
+			WARN_ON(1);
+			dev_kfree_skb(skb);
+			return NULL;
+		}
+	}
+
+	return skb;
+}
+
+static inline bool should_drop_frame(struct sk_buff *skb, int present_fcs_len)
+{
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
+	struct ieee80211_hdr *hdr = (void *)skb->data;
+
+	if (status->flag & (RX_FLAG_FAILED_FCS_CRC |
+			    RX_FLAG_FAILED_PLCP_CRC |
+			    RX_FLAG_AMPDU_IS_ZEROLEN))
+		return true;
+
+	if (unlikely(skb->len < 16 + present_fcs_len))
+		return true;
+
+	if (ieee80211_is_ctl(hdr->frame_control) &&
+	    !ieee80211_is_pspoll(hdr->frame_control) &&
+	    !ieee80211_is_back_req(hdr->frame_control))
+		return true;
+
+	return false;
+}
+
+static int
+ieee80211_rx_radiotap_space(struct ieee80211_local *local,
+			    struct ieee80211_rx_status *status)
+{
+	int len;
+
+	/* always present fields */
+	len = sizeof(struct ieee80211_radiotap_header) + 8;
+
+	/* allocate extra bitmaps */
+	if (status->chains)
+		len += 4 * hweight8(status->chains);
+
+	if (ieee80211_have_rx_timestamp(status)) {
+		len = ALIGN(len, 8);
+		len += 8;
+	}
+	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
+		len += 1;
+
+	/* antenna field, if we don't have per-chain info */
+	if (!status->chains)
+		len += 1;
+
+	/* padding for RX_FLAGS if necessary */
+	len = ALIGN(len, 2);
+
+	if (status->flag & RX_FLAG_HT) /* HT info */
+		len += 3;
+
+	if (status->flag & RX_FLAG_AMPDU_DETAILS) {
+		len = ALIGN(len, 4);
+		len += 8;
+	}
+
+	if (status->flag & RX_FLAG_VHT) {
+		len = ALIGN(len, 2);
+		len += 12;
+	}
+
+	if (status->chains) {
+		/* antenna and antenna signal fields */
+		len += 2 * hweight8(status->chains);
+	}
+
+	return len;
+}
+
+/*
+ * ieee80211_add_rx_radiotap_header - add radiotap header
+ *
+ * add a radiotap header containing all the fields which the hardware provided.
+ */
+static void
+ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
+				 struct sk_buff *skb,
+				 struct ieee80211_rate *rate,
+				 int rtap_len, bool has_fcs)
+{
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
+	struct ieee80211_radiotap_header *rthdr;
+	unsigned char *pos;
+	__le32 *it_present;
+	u32 it_present_val;
+	u16 rx_flags = 0;
+	u16 channel_flags = 0;
+	int mpdulen, chain;
+	unsigned long chains = status->chains;
+
+	mpdulen = skb->len;
+	if (!(has_fcs && (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)))
+		mpdulen += FCS_LEN;
+
+	rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
+	memset(rthdr, 0, rtap_len);
+	it_present = &rthdr->it_present;
+
+	/* radiotap header, set always present flags */
+	rthdr->it_len = cpu_to_le16(rtap_len);
+	it_present_val = BIT(IEEE80211_RADIOTAP_FLAGS) |
+			 BIT(IEEE80211_RADIOTAP_CHANNEL) |
+			 BIT(IEEE80211_RADIOTAP_RX_FLAGS);
+
+	if (!status->chains)
+		it_present_val |= BIT(IEEE80211_RADIOTAP_ANTENNA);
+
+	for_each_set_bit(chain, &chains, IEEE80211_MAX_CHAINS) {
+		it_present_val |=
+			BIT(IEEE80211_RADIOTAP_EXT) |
+			BIT(IEEE80211_RADIOTAP_RADIOTAP_NAMESPACE);
+		put_unaligned_le32(it_present_val, it_present);
+		it_present++;
+		it_present_val = BIT(IEEE80211_RADIOTAP_ANTENNA) |
+				 BIT(IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
+	}
+
+	put_unaligned_le32(it_present_val, it_present);
+
+	pos = (void *)(it_present + 1);
+
+	/* the order of the following fields is important */
+
+	/* IEEE80211_RADIOTAP_TSFT */
+	if (ieee80211_have_rx_timestamp(status)) {
+		/* padding */
+		while ((pos - (u8 *)rthdr) & 7)
+			*pos++ = 0;
+		put_unaligned_le64(
+			ieee80211_calculate_rx_timestamp(local, status,
+							 mpdulen, 0),
+			pos);
+		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
+		pos += 8;
+	}
+
+	/* IEEE80211_RADIOTAP_FLAGS */
+	if (has_fcs && (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS))
+		*pos |= IEEE80211_RADIOTAP_F_FCS;
+	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
+		*pos |= IEEE80211_RADIOTAP_F_BADFCS;
+	if (status->flag & RX_FLAG_SHORTPRE)
+		*pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
+	pos++;
+
+	/* IEEE80211_RADIOTAP_RATE */
+	if (!rate || status->flag & (RX_FLAG_HT | RX_FLAG_VHT)) {
+		/*
+		 * Without rate information don't add it. If we have,
+		 * MCS information is a separate field in radiotap,
+		 * added below. The byte here is needed as padding
+		 * for the channel though, so initialise it to 0.
+		 */
+		*pos = 0;
+	} else {
+		int shift = 0;
+		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
+		if (status->flag & RX_FLAG_10MHZ)
+			shift = 1;
+		else if (status->flag & RX_FLAG_5MHZ)
+			shift = 2;
+		*pos = DIV_ROUND_UP(rate->bitrate, 5 * (1 << shift));
+	}
+	pos++;
+
+	/* IEEE80211_RADIOTAP_CHANNEL */
+	put_unaligned_le16(status->freq, pos);
+	pos += 2;
+	if (status->flag & RX_FLAG_10MHZ)
+		channel_flags |= IEEE80211_CHAN_HALF;
+	else if (status->flag & RX_FLAG_5MHZ)
+		channel_flags |= IEEE80211_CHAN_QUARTER;
+
+	if (status->band == IEEE80211_BAND_5GHZ)
+		channel_flags |= IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ;
+	else if (status->flag & (RX_FLAG_HT | RX_FLAG_VHT))
+		channel_flags |= IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ;
+	else if (rate && rate->flags & IEEE80211_RATE_ERP_G)
+		channel_flags |= IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ;
+	else if (rate)
+		channel_flags |= IEEE80211_CHAN_CCK | IEEE80211_CHAN_2GHZ;
+	else
+		channel_flags |= IEEE80211_CHAN_2GHZ;
+	put_unaligned_le16(channel_flags, pos);
+	pos += 2;
+
+	/* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
+	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM &&
+	    !(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
+		*pos = status->signal;
+		rthdr->it_present |=
+			cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
+		pos++;
+	}
+
+	/* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */
+
+	if (!status->chains) {
+		/* IEEE80211_RADIOTAP_ANTENNA */
+		*pos = status->antenna;
+		pos++;
+	}
+
+	/* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */
+
+	/* IEEE80211_RADIOTAP_RX_FLAGS */
+	/* ensure 2 byte alignment for the 2 byte field as required */
+	if ((pos - (u8 *)rthdr) & 1)
+		*pos++ = 0;
+	if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
+		rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
+	put_unaligned_le16(rx_flags, pos);
+	pos += 2;
+
+	if (status->flag & RX_FLAG_HT) {
+		unsigned int stbc;
+
+		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
+		*pos++ = local->hw.radiotap_mcs_details;
+		*pos = 0;
+		if (status->flag & RX_FLAG_SHORT_GI)
+			*pos |= IEEE80211_RADIOTAP_MCS_SGI;
+		if (status->flag & RX_FLAG_40MHZ)
+			*pos |= IEEE80211_RADIOTAP_MCS_BW_40;
+		if (status->flag & RX_FLAG_HT_GF)
+			*pos |= IEEE80211_RADIOTAP_MCS_FMT_GF;
+		if (status->flag & RX_FLAG_LDPC)
+			*pos |= IEEE80211_RADIOTAP_MCS_FEC_LDPC;
+		stbc = (status->flag & RX_FLAG_STBC_MASK) >> RX_FLAG_STBC_SHIFT;
+		*pos |= stbc << IEEE80211_RADIOTAP_MCS_STBC_SHIFT;
+		pos++;
+		*pos++ = status->rate_idx;
+	}
+
+	if (status->flag & RX_FLAG_AMPDU_DETAILS) {
+		u16 flags = 0;
+
+		/* ensure 4 byte alignment */
+		while ((pos - (u8 *)rthdr) & 3)
+			pos++;
+		rthdr->it_present |=
+			cpu_to_le32(1 << IEEE80211_RADIOTAP_AMPDU_STATUS);
+		put_unaligned_le32(status->ampdu_reference, pos);
+		pos += 4;
+		if (status->flag & RX_FLAG_AMPDU_REPORT_ZEROLEN)
+			flags |= IEEE80211_RADIOTAP_AMPDU_REPORT_ZEROLEN;
+		if (status->flag & RX_FLAG_AMPDU_IS_ZEROLEN)
+			flags |= IEEE80211_RADIOTAP_AMPDU_IS_ZEROLEN;
+		if (status->flag & RX_FLAG_AMPDU_LAST_KNOWN)
+			flags |= IEEE80211_RADIOTAP_AMPDU_LAST_KNOWN;
+		if (status->flag & RX_FLAG_AMPDU_IS_LAST)
+			flags |= IEEE80211_RADIOTAP_AMPDU_IS_LAST;
+		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_ERROR)
+			flags |= IEEE80211_RADIOTAP_AMPDU_DELIM_CRC_ERR;
+		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_KNOWN)
+			flags |= IEEE80211_RADIOTAP_AMPDU_DELIM_CRC_KNOWN;
+		put_unaligned_le16(flags, pos);
+		pos += 2;
+		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_KNOWN)
+			*pos++ = status->ampdu_delimiter_crc;
+		else
+			*pos++ = 0;
+		*pos++ = 0;
+	}
+
+	if (status->flag & RX_FLAG_VHT) {
+		u16 known = local->hw.radiotap_vht_details;
+
+		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_VHT);
+		/* known field - how to handle 80+80? */
+		if (status->vht_flag & RX_VHT_FLAG_80P80MHZ)
+			known &= ~IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH;
+		put_unaligned_le16(known, pos);
+		pos += 2;
+		/* flags */
+		if (status->flag & RX_FLAG_SHORT_GI)
+			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_SGI;
+		/* in VHT, STBC is binary */
+		if (status->flag & RX_FLAG_STBC_MASK)
+			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_STBC;
+		if (status->vht_flag & RX_VHT_FLAG_BF)
+			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_BEAMFORMED;
+		pos++;
+		/* bandwidth */
+		if (status->vht_flag & RX_VHT_FLAG_80MHZ)
+			*pos++ = 4;
+		else if (status->vht_flag & RX_VHT_FLAG_80P80MHZ)
+			*pos++ = 0; /* marked not known above */
+		else if (status->vht_flag & RX_VHT_FLAG_160MHZ)
+			*pos++ = 11;
+		else if (status->flag & RX_FLAG_40MHZ)
+			*pos++ = 1;
+		else /* 20 MHz */
+			*pos++ = 0;
+		/* MCS/NSS */
+		*pos = (status->rate_idx << 4) | status->vht_nss;
+		pos += 4;
+		/* coding field */
+		if (status->flag & RX_FLAG_LDPC)
+			*pos |= IEEE80211_RADIOTAP_CODING_LDPC_USER0;
+		pos++;
+		/* group ID */
+		pos++;
+		/* partial_aid */
+		pos += 2;
+	}
+
+	for_each_set_bit(chain, &chains, IEEE80211_MAX_CHAINS) {
+		*pos++ = status->chain_signal[chain];
+		*pos++ = chain;
+	}
+}
+
+/*
+ * This function copies a received frame to all monitor interfaces and
+ * returns a cleaned-up SKB that no longer includes the FCS nor the
+ * radiotap header the driver might have added.
+ */
+static struct sk_buff *
+ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
+		     struct ieee80211_rate *rate)
+{
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
+	struct ieee80211_sub_if_data *sdata;
+	int needed_headroom;
+	struct sk_buff *skb, *skb2;
+	struct net_device *prev_dev = NULL;
+	int present_fcs_len = 0;
+
+	/*
+	 * First, we may need to make a copy of the skb because
+	 *  (1) we need to modify it for radiotap (if not present), and
+	 *  (2) the other RX handlers will modify the skb we got.
+	 *
+	 * We don't need to, of course, if we aren't going to return
+	 * the SKB because it has a bad FCS/PLCP checksum.
+	 */
+
+	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
+		present_fcs_len = FCS_LEN;
+
+	/* ensure hdr->frame_control is in skb head */
+	if (!pskb_may_pull(origskb, 2)) {
+		dev_kfree_skb(origskb);
+		return NULL;
+	}
+
+	if (!local->monitors) {
+		if (should_drop_frame(origskb, present_fcs_len)) {
+			dev_kfree_skb(origskb);
+			return NULL;
+		}
+
+		return remove_monitor_info(local, origskb);
+	}
+
+	/* room for the radiotap header based on driver features */
+	needed_headroom = ieee80211_rx_radiotap_space(local, status);
+
+	if (should_drop_frame(origskb, present_fcs_len)) {
+		/* only need to expand headroom if necessary */
+		skb = origskb;
+		origskb = NULL;
+
+		/*
+		 * This shouldn't trigger often because most devices have an
+		 * RX header they pull before we get here, and that should
+		 * be big enough for our radiotap information. We should
+		 * probably export the length to drivers so that we can have
+		 * them allocate enough headroom to start with.
+		 */
+		if (skb_headroom(skb) < needed_headroom &&
+		    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
+			dev_kfree_skb(skb);
+			return NULL;
+		}
+	} else {
+		/*
+		 * Need to make a copy and possibly remove radiotap header
+		 * and FCS from the original.
+		 */
+		skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);
+
+		origskb = remove_monitor_info(local, origskb);
+
+		if (!skb)
+			return origskb;
+	}
+
+	/* prepend radiotap information */
+	ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom,
+					 true);
+
+	skb_reset_mac_header(skb);
+	skb->ip_summed = CHECKSUM_UNNECESSARY;
+	skb->pkt_type = PACKET_OTHERHOST;
+	skb->protocol = htons(ETH_P_802_2);
+
+	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
+		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
+			continue;
+
+		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
+			continue;
+
+		if (!ieee80211_sdata_running(sdata))
+			continue;
+
+		if (prev_dev) {
+			skb2 = skb_clone(skb, GFP_ATOMIC);
+			if (skb2) {
+				skb2->dev = prev_dev;
+				netif_receive_skb(skb2);
+			}
+		}
+
+		prev_dev = sdata->dev;
+		sdata->dev->stats.rx_packets++;
+		sdata->dev->stats.rx_bytes += skb->len;
+	}
+
+	if (prev_dev) {
+		skb->dev = prev_dev;
+		netif_receive_skb(skb);
+	} else
+		dev_kfree_skb(skb);
+
+	return origskb;
+}
+
+static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
+{
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
+	int tid, seqno_idx, security_idx;
+
+	/* does the frame have a qos control field? */
+	if (ieee80211_is_data_qos(hdr->frame_control)) {
+		u8 *qc = ieee80211_get_qos_ctl(hdr);
+		/* frame has qos control */
+		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
+		if (*qc & IEEE80211_QOS_CTL_A_MSDU_PRESENT)
+			status->rx_flags |= IEEE80211_RX_AMSDU;
+
+		seqno_idx = tid;
+		security_idx = tid;
+	} else {
+		/*
+		 * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
+		 *
+		 *	Sequence numbers for management frames, QoS data
+		 *	frames with a broadcast/multicast address in the
+		 *	Address 1 field, and all non-QoS data frames sent
+		 *	by QoS STAs are assigned using an additional single
+		 *	modulo-4096 counter, [...]
+		 *
+		 * We also use that counter for non-QoS STAs.
+		 */
+		seqno_idx = IEEE80211_NUM_TIDS;
+		security_idx = 0;
+		if (ieee80211_is_mgmt(hdr->frame_control))
+			security_idx = IEEE80211_NUM_TIDS;
+		tid = 0;
+	}
+
+	rx->seqno_idx = seqno_idx;
+	rx->security_idx = security_idx;
+	/* Set skb->priority to 1d tag if highest order bit of TID is not set.
+	 * For now, set skb->priority to 0 for other cases. */
+	rx->skb->priority = (tid > 7) ? 0 : tid;
+}
+
+/**
+ * DOC: Packet alignment
+ *
+ * Drivers always need to pass packets that are aligned to two-byte boundaries
+ * to the stack.
+ *
+ * Additionally, should, if possible, align the payload data in a way that
+ * guarantees that the contained IP header is aligned to a four-byte
+ * boundary. In the case of regular frames, this simply means aligning the
+ * payload to a four-byte boundary (because either the IP header is directly
+ * contained, or IV/RFC1042 headers that have a length divisible by four are
+ * in front of it).  If the payload data is not properly aligned and the
+ * architecture doesn't support efficient unaligned operations, mac80211
+ * will align the data.
+ *
+ * With A-MSDU frames, however, the payload data address must yield two modulo
+ * four because there are 14-byte 802.3 headers within the A-MSDU frames that
+ * push the IP header further back to a multiple of four again. Thankfully, the
+ * specs were sane enough this time around to require padding each A-MSDU
+ * subframe to a length that is a multiple of four.
+ *
+ * Padding like Atheros hardware adds which is between the 802.11 header and
+ * the payload is not supported, the driver is required to move the 802.11
+ * header to be directly in front of the payload in that case.
+ */
+static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
+{
+#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
+	WARN_ONCE((unsigned long)rx->skb->data & 1,
+		  "unaligned packet at 0x%p\n", rx->skb->data);
+#endif
+}
+
+
+/* rx handlers */
+
+static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
+{
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+
+	if (is_multicast_ether_addr(hdr->addr1))
+		return 0;
+
+	return ieee80211_is_robust_mgmt_frame(skb);
+}
+
+
+static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
+{
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+
+	if (!is_multicast_ether_addr(hdr->addr1))
+		return 0;
+
+	return ieee80211_is_robust_mgmt_frame(skb);
+}
+
+
+/* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
+static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
+{
+	struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
+	struct ieee80211_mmie *mmie;
+
+	if (skb->len < 24 + sizeof(*mmie) || !is_multicast_ether_addr(hdr->da))
+		return -1;
+
+	if (!ieee80211_is_robust_mgmt_frame(skb))
+		return -1; /* not a robust management frame */
+
+	mmie = (struct ieee80211_mmie *)
+		(skb->data + skb->len - sizeof(*mmie));
+	if (mmie->element_id != WLAN_EID_MMIE ||
+	    mmie->length != sizeof(*mmie) - 2)
+		return -1;
+
+	return le16_to_cpu(mmie->key_id);
+}
+
+static int iwl80211_get_cs_keyid(const struct ieee80211_cipher_scheme *cs,
+				 struct sk_buff *skb)
+{
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
+	__le16 fc;
+	int hdrlen;
+	u8 keyid;
+
+	fc = hdr->frame_control;
+	hdrlen = ieee80211_hdrlen(fc);
+
+	if (skb->len < hdrlen + cs->hdr_len)
+		return -EINVAL;
+
+	skb_copy_bits(skb, hdrlen + cs->key_idx_off, &keyid, 1);
+	keyid &= cs->key_idx_mask;
+	keyid >>= cs->key_idx_shift;
+
+	return keyid;
+}
+
+static ieee80211_rx_result ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
+{
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
+	char *dev_addr = rx->sdata->vif.addr;
+
+	if (ieee80211_is_data(hdr->frame_control)) {
+		if (is_multicast_ether_addr(hdr->addr1)) {
+			if (ieee80211_has_tods(hdr->frame_control) ||
+			    !ieee80211_has_fromds(hdr->frame_control))
+				return RX_DROP_MONITOR;
+			if (ether_addr_equal(hdr->addr3, dev_addr))
+				return RX_DROP_MONITOR;
+		} else {
+			if (!ieee80211_has_a4(hdr->frame_control))
+				return RX_DROP_MONITOR;
+			if (ether_addr_equal(hdr->addr4, dev_addr))
+				return RX_DROP_MONITOR;
+		}
+	}
+
+	/* If there is not an established peer link and this is not a peer link
+	 * establisment frame, beacon or probe, drop the frame.
+	 */
+
+	if (!rx->sta || sta_plink_state(rx->sta) != NL80211_PLINK_ESTAB) {
+		struct ieee80211_mgmt *mgmt;
+
+		if (!ieee80211_is_mgmt(hdr->frame_control))
+			return RX_DROP_MONITOR;
+
+		if (ieee80211_is_action(hdr->frame_control)) {
+			u8 category;
+
+			/* make sure category field is present */
+			if (rx->skb->len < IEEE80211_MIN_ACTION_SIZE)
+				return RX_DROP_MONITOR;
+
+			mgmt = (struct ieee80211_mgmt *)hdr;
+			category = mgmt->u.action.category;
+			if (category != WLAN_CATEGORY_MESH_ACTION &&
+			    category != WLAN_CATEGORY_SELF_PROTECTED)
+				return RX_DROP_MONITOR;
+			return RX_CONTINUE;
+		}
+
+		if (ieee80211_is_probe_req(hdr->frame_control) ||
+		    ieee80211_is_probe_resp(hdr->frame_control) ||
+		    ieee80211_is_beacon(hdr->frame_control) ||
+		    ieee80211_is_auth(hdr->frame_control))
+			return RX_CONTINUE;
+
+		return RX_DROP_MONITOR;
+	}
+
+	return RX_CONTINUE;
+}
+
+static void ieee80211_release_reorder_frame(struct ieee80211_sub_if_data *sdata,
+					    struct tid_ampdu_rx *tid_agg_rx,
+					    int index,
+					    struct sk_buff_head *frames)
+{
+	struct sk_buff_head *skb_list = &tid_agg_rx->reorder_buf[index];
+	struct sk_buff *skb;
+	struct ieee80211_rx_status *status;
+
+	lockdep_assert_held(&tid_agg_rx->reorder_lock);
+
+	if (skb_queue_empty(skb_list))
+		goto no_frame;
+
+	if (!ieee80211_rx_reorder_ready(skb_list)) {
+		__skb_queue_purge(skb_list);
+		goto no_frame;
+	}
+
+	/* release frames from the reorder ring buffer */
+	tid_agg_rx->stored_mpdu_num--;
+	while ((skb = __skb_dequeue(skb_list))) {
+		status = IEEE80211_SKB_RXCB(skb);
+		status->rx_flags |= IEEE80211_RX_DEFERRED_RELEASE;
+		__skb_queue_tail(frames, skb);
+	}
+
+no_frame:
+	tid_agg_rx->head_seq_num = ieee80211_sn_inc(tid_agg_rx->head_seq_num);
+}
+
+static void ieee80211_release_reorder_frames(struct ieee80211_sub_if_data *sdata,
+					     struct tid_ampdu_rx *tid_agg_rx,
+					     u16 head_seq_num,
+					     struct sk_buff_head *frames)
+{
+	int index;
+
+	lockdep_assert_held(&tid_agg_rx->reorder_lock);
+
+	while (ieee80211_sn_less(tid_agg_rx->head_seq_num, head_seq_num)) {
+		index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
+		ieee80211_release_reorder_frame(sdata, tid_agg_rx, index,
+						frames);
+	}
+}
+
+/*
+ * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
+ * the skb was added to the buffer longer than this time ago, the earlier
+ * frames that have not yet been received are assumed to be lost and the skb
+ * can be released for processing. This may also release other skb's from the
+ * reorder buffer if there are no additional gaps between the frames.
+ *
+ * Callers must hold tid_agg_rx->reorder_lock.
+ */
+#define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)
+
+static void ieee80211_sta_reorder_release(struct ieee80211_sub_if_data *sdata,
+					  struct tid_ampdu_rx *tid_agg_rx,
+					  struct sk_buff_head *frames)
+{
+	int index, i, j;
+
+	lockdep_assert_held(&tid_agg_rx->reorder_lock);
+
+	/* release the buffer until next missing frame */
+	index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
+	if (!ieee80211_rx_reorder_ready(&tid_agg_rx->reorder_buf[index]) &&
+	    tid_agg_rx->stored_mpdu_num) {
+		/*
+		 * No buffers ready to be released, but check whether any
+		 * frames in the reorder buffer have timed out.
+		 */
+		int skipped = 1;
+		for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
+		     j = (j + 1) % tid_agg_rx->buf_size) {
+			if (!ieee80211_rx_reorder_ready(
+					&tid_agg_rx->reorder_buf[j])) {
+				skipped++;
+				continue;
+			}
+			if (skipped &&
+			    !time_after(jiffies, tid_agg_rx->reorder_time[j] +
+					HT_RX_REORDER_BUF_TIMEOUT))
+				goto set_release_timer;
+
+			/* don't leave incomplete A-MSDUs around */
+			for (i = (index + 1) % tid_agg_rx->buf_size; i != j;
+			     i = (i + 1) % tid_agg_rx->buf_size)
+				__skb_queue_purge(&tid_agg_rx->reorder_buf[i]);
+
+			ht_dbg_ratelimited(sdata,
+					   "release an RX reorder frame due to timeout on earlier frames\n");
+			ieee80211_release_reorder_frame(sdata, tid_agg_rx, j,
+							frames);
+
+			/*
+			 * Increment the head seq# also for the skipped slots.
+			 */
+			tid_agg_rx->head_seq_num =
+				(tid_agg_rx->head_seq_num +
+				 skipped) & IEEE80211_SN_MASK;
+			skipped = 0;
+		}
+	} else while (ieee80211_rx_reorder_ready(
+				&tid_agg_rx->reorder_buf[index])) {
+		ieee80211_release_reorder_frame(sdata, tid_agg_rx, index,
+						frames);
+		index =	tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
+	}
+
+	if (tid_agg_rx->stored_mpdu_num) {
+		j = index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
+
+		for (; j != (index - 1) % tid_agg_rx->buf_size;
+		     j = (j + 1) % tid_agg_rx->buf_size) {
+			if (ieee80211_rx_reorder_ready(
+					&tid_agg_rx->reorder_buf[j]))
+				break;
+		}
+
+ set_release_timer:
+
+		mod_timer(&tid_agg_rx->reorder_timer,
+			  tid_agg_rx->reorder_time[j] + 1 +
+			  HT_RX_REORDER_BUF_TIMEOUT);
+	} else {
+		del_timer(&tid_agg_rx->reorder_timer);
+	}
+}
+
+/*
+ * As this function belongs to the RX path it must be under
+ * rcu_read_lock protection. It returns false if the frame
+ * can be processed immediately, true if it was consumed.
+ */
+static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_sub_if_data *sdata,
+					     struct tid_ampdu_rx *tid_agg_rx,
+					     struct sk_buff *skb,
+					     struct sk_buff_head *frames)
+{
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
+	u16 sc = le16_to_cpu(hdr->seq_ctrl);
+	u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
+	u16 head_seq_num, buf_size;
+	int index;
+	bool ret = true;
+
+	spin_lock(&tid_agg_rx->reorder_lock);
+
+	/*
+	 * Offloaded BA sessions have no known starting sequence number so pick
+	 * one from first Rxed frame for this tid after BA was started.
+	 */
+	if (unlikely(tid_agg_rx->auto_seq)) {
+		tid_agg_rx->auto_seq = false;
+		tid_agg_rx->ssn = mpdu_seq_num;
+		tid_agg_rx->head_seq_num = mpdu_seq_num;
+	}
+
+	buf_size = tid_agg_rx->buf_size;
+	head_seq_num = tid_agg_rx->head_seq_num;
+
+	/* frame with out of date sequence number */
+	if (ieee80211_sn_less(mpdu_seq_num, head_seq_num)) {
+		dev_kfree_skb(skb);
+		goto out;
+	}
+
+	/*
+	 * If frame the sequence number exceeds our buffering window
+	 * size release some previous frames to make room for this one.
+	 */
+	if (!ieee80211_sn_less(mpdu_seq_num, head_seq_num + buf_size)) {
+		head_seq_num = ieee80211_sn_inc(
+				ieee80211_sn_sub(mpdu_seq_num, buf_size));
+		/* release stored frames up to new head to stack */
+		ieee80211_release_reorder_frames(sdata, tid_agg_rx,
+						 head_seq_num, frames);
+	}
+
+	/* Now the new frame is always in the range of the reordering buffer */
+
+	index = mpdu_seq_num % tid_agg_rx->buf_size;
+
+	/* check if we already stored this frame */
+	if (ieee80211_rx_reorder_ready(&tid_agg_rx->reorder_buf[index])) {
+		dev_kfree_skb(skb);
+		goto out;
+	}
+
+	/*
+	 * If the current MPDU is in the right order and nothing else
+	 * is stored we can process it directly, no need to buffer it.
+	 * If it is first but there's something stored, we may be able
+	 * to release frames after this one.
+	 */
+	if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
+	    tid_agg_rx->stored_mpdu_num == 0) {
+		if (!(status->flag & RX_FLAG_AMSDU_MORE))
+			tid_agg_rx->head_seq_num =
+				ieee80211_sn_inc(tid_agg_rx->head_seq_num);
+		ret = false;
+		goto out;
+	}
+
+	/* put the frame in the reordering buffer */
+	__skb_queue_tail(&tid_agg_rx->reorder_buf[index], skb);
+	if (!(status->flag & RX_FLAG_AMSDU_MORE)) {
+		tid_agg_rx->reorder_time[index] = jiffies;
+		tid_agg_rx->stored_mpdu_num++;
+		ieee80211_sta_reorder_release(sdata, tid_agg_rx, frames);
+	}
+
+ out:
+	spin_unlock(&tid_agg_rx->reorder_lock);
+	return ret;
+}
+
+/*
+ * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
+ * true if the MPDU was buffered, false if it should be processed.
+ */
+static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx,
+				       struct sk_buff_head *frames)
+{
+	struct sk_buff *skb = rx->skb;
+	struct ieee80211_local *local = rx->local;
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
+	struct sta_info *sta = rx->sta;
+	struct tid_ampdu_rx *tid_agg_rx;
+	u16 sc;
+	u8 tid, ack_policy;
+
+	if (!ieee80211_is_data_qos(hdr->frame_control) ||
+	    is_multicast_ether_addr(hdr->addr1))
+		goto dont_reorder;
+
+	/*
+	 * filter the QoS data rx stream according to
+	 * STA/TID and check if this STA/TID is on aggregation
+	 */
+
+	if (!sta)
+		goto dont_reorder;
+
+	ack_policy = *ieee80211_get_qos_ctl(hdr) &
+		     IEEE80211_QOS_CTL_ACK_POLICY_MASK;
+	tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
+
+	tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
+	if (!tid_agg_rx)
+		goto dont_reorder;
+
+	/* qos null data frames are excluded */
+	if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
+		goto dont_reorder;
+
+	/* not part of a BA session */
+	if (ack_policy != IEEE80211_QOS_CTL_ACK_POLICY_BLOCKACK &&
+	    ack_policy != IEEE80211_QOS_CTL_ACK_POLICY_NORMAL)
+		goto dont_reorder;
+
+	/* not actually part of this BA session */
+	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
+		goto dont_reorder;
+
+	/* new, potentially un-ordered, ampdu frame - process it */
+
+	/* reset session timer */
+	if (tid_agg_rx->timeout)
+		tid_agg_rx->last_rx = jiffies;
+
+	/* if this mpdu is fragmented - terminate rx aggregation session */
+	sc = le16_to_cpu(hdr->seq_ctrl);
+	if (sc & IEEE80211_SCTL_FRAG) {
+		skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
+		skb_queue_tail(&rx->sdata->skb_queue, skb);
+		ieee80211_queue_work(&local->hw, &rx->sdata->work);
+		return;
+	}
+
+	/*
+	 * No locking needed -- we will only ever process one
+	 * RX packet at a time, and thus own tid_agg_rx. All
+	 * other code manipulating it needs to (and does) make
+	 * sure that we cannot get to it any more before doing
+	 * anything with it.
+	 */
+	if (ieee80211_sta_manage_reorder_buf(rx->sdata, tid_agg_rx, skb,
+					     frames))
+		return;
+
+ dont_reorder:
+	__skb_queue_tail(frames, skb);
+}
+
+static ieee80211_rx_result debug_noinline
+ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
+{
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
+
+	/*
+	 * Drop duplicate 802.11 retransmissions
+	 * (IEEE 802.11-2012: 9.3.2.10 "Duplicate detection and recovery")
+	 */
+	if (rx->skb->len >= 24 && rx->sta &&
+	    !ieee80211_is_ctl(hdr->frame_control) &&
+	    !ieee80211_is_qos_nullfunc(hdr->frame_control) &&
+	    !is_multicast_ether_addr(hdr->addr1)) {
+		if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
+			     rx->sta->last_seq_ctrl[rx->seqno_idx] ==
+			     hdr->seq_ctrl)) {
+			if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
+				rx->local->dot11FrameDuplicateCount++;
+				rx->sta->num_duplicates++;
+			}
+			return RX_DROP_UNUSABLE;
+		} else if (!(status->flag & RX_FLAG_AMSDU_MORE)) {
+			rx->sta->last_seq_ctrl[rx->seqno_idx] = hdr->seq_ctrl;
+		}
+	}
+
+	if (unlikely(rx->skb->len < 16)) {
+		I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
+		return RX_DROP_MONITOR;
+	}
+
+	/* Drop disallowed frame classes based on STA auth/assoc state;
+	 * IEEE 802.11, Chap 5.5.
+	 *
+	 * mac80211 filters only based on association state, i.e. it drops
+	 * Class 3 frames from not associated stations. hostapd sends
+	 * deauth/disassoc frames when needed. In addition, hostapd is
+	 * responsible for filtering on both auth and assoc states.
+	 */
+
+	if (ieee80211_vif_is_mesh(&rx->sdata->vif))
+		return ieee80211_rx_mesh_check(rx);
+
+	if (unlikely((ieee80211_is_data(hdr->frame_control) ||
+		      ieee80211_is_pspoll(hdr->frame_control)) &&
+		     rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
+		     rx->sdata->vif.type != NL80211_IFTYPE_WDS &&
+		     (!rx->sta || !test_sta_flag(rx->sta, WLAN_STA_ASSOC)))) {
+		/*
+		 * accept port control frames from the AP even when it's not
+		 * yet marked ASSOC to prevent a race where we don't set the
+		 * assoc bit quickly enough before it sends the first frame
+		 */
+		if (rx->sta && rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
+		    ieee80211_is_data_present(hdr->frame_control)) {
+			unsigned int hdrlen;
+			__be16 ethertype;
+
+			hdrlen = ieee80211_hdrlen(hdr->frame_control);
+
+			if (rx->skb->len < hdrlen + 8)
+				return RX_DROP_MONITOR;
+
+			skb_copy_bits(rx->skb, hdrlen + 6, &ethertype, 2);
+			if (ethertype == rx->sdata->control_port_protocol)
+				return RX_CONTINUE;
+		}
+
+		if (rx->sdata->vif.type == NL80211_IFTYPE_AP &&
+		    cfg80211_rx_spurious_frame(rx->sdata->dev,
+					       hdr->addr2,
+					       GFP_ATOMIC))
+			return RX_DROP_UNUSABLE;
+
+		return RX_DROP_MONITOR;
+	}
+
+	return RX_CONTINUE;
+}
+
+
+static ieee80211_rx_result debug_noinline
+ieee80211_rx_h_check_more_data(struct ieee80211_rx_data *rx)
+{
+	struct ieee80211_local *local;
+	struct ieee80211_hdr *hdr;
+	struct sk_buff *skb;
+
+	local = rx->local;
+	skb = rx->skb;
+	hdr = (struct ieee80211_hdr *) skb->data;
+
+	if (!local->pspolling)
+		return RX_CONTINUE;
+
+	if (!ieee80211_has_fromds(hdr->frame_control))
+		/* this is not from AP */
+		return RX_CONTINUE;
+
+	if (!ieee80211_is_data(hdr->frame_control))
+		return RX_CONTINUE;
+
+	if (!ieee80211_has_moredata(hdr->frame_control)) {
+		/* AP has no more frames buffered for us */
+		local->pspolling = false;
+		return RX_CONTINUE;
+	}
+
+	/* more data bit is set, let's request a new frame from the AP */
+	ieee80211_send_pspoll(local, rx->sdata);
+
+	return RX_CONTINUE;
+}
+
+static void sta_ps_start(struct sta_info *sta)
+{
+	struct ieee80211_sub_if_data *sdata = sta->sdata;
+	struct ieee80211_local *local = sdata->local;
+	struct ps_data *ps;
+
+	if (sta->sdata->vif.type == NL80211_IFTYPE_AP ||
+	    sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
+		ps = &sdata->bss->ps;
+	else
+		return;
+
+	atomic_inc(&ps->num_sta_ps);
+	set_sta_flag(sta, WLAN_STA_PS_STA);
+	if (!(local->hw.flags & IEEE80211_HW_AP_LINK_PS))
+		drv_sta_notify(local, sdata, STA_NOTIFY_SLEEP, &sta->sta);
+	ps_dbg(sdata, "STA %pM aid %d enters power save mode\n",
+	       sta->sta.addr, sta->sta.aid);
+}
+
+static void sta_ps_end(struct sta_info *sta)
+{
+	ps_dbg(sta->sdata, "STA %pM aid %d exits power save mode\n",
+	       sta->sta.addr, sta->sta.aid);
+
+	if (test_sta_flag(sta, WLAN_STA_PS_DRIVER)) {
+		/*
+		 * Clear the flag only if the other one is still set
+		 * so that the TX path won't start TX'ing new frames
+		 * directly ... In the case that the driver flag isn't
+		 * set ieee80211_sta_ps_deliver_wakeup() will clear it.
+		 */
+		clear_sta_flag(sta, WLAN_STA_PS_STA);
+		ps_dbg(sta->sdata, "STA %pM aid %d driver-ps-blocked\n",
+		       sta->sta.addr, sta->sta.aid);
+		return;
+	}
+
+	set_sta_flag(sta, WLAN_STA_PS_DELIVER);
+	clear_sta_flag(sta, WLAN_STA_PS_STA);
+	ieee80211_sta_ps_deliver_wakeup(sta);
+}
+
+int ieee80211_sta_ps_transition(struct ieee80211_sta *sta, bool start)
+{
+	struct sta_info *sta_inf = container_of(sta, struct sta_info, sta);
+	bool in_ps;
+
+	WARN_ON(!(sta_inf->local->hw.flags & IEEE80211_HW_AP_LINK_PS));
+
+	/* Don't let the same PS state be set twice */
+	in_ps = test_sta_flag(sta_inf, WLAN_STA_PS_STA);
+	if ((start && in_ps) || (!start && !in_ps))
+		return -EINVAL;
+
+	if (start)
+		sta_ps_start(sta_inf);
+	else
+		sta_ps_end(sta_inf);
+
+	return 0;
+}
+EXPORT_SYMBOL(ieee80211_sta_ps_transition);
+
+static ieee80211_rx_result debug_noinline
+ieee80211_rx_h_uapsd_and_pspoll(struct ieee80211_rx_data *rx)
+{
+	struct ieee80211_sub_if_data *sdata = rx->sdata;
+	struct ieee80211_hdr *hdr = (void *)rx->skb->data;
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
+	int tid, ac;
+
+	if (!rx->sta || !(status->rx_flags & IEEE80211_RX_RA_MATCH))
+		return RX_CONTINUE;
+
+	if (sdata->vif.type != NL80211_IFTYPE_AP &&
+	    sdata->vif.type != NL80211_IFTYPE_AP_VLAN)
+		return RX_CONTINUE;
+
+	/*
+	 * The device handles station powersave, so don't do anything about
+	 * uAPSD and PS-Poll frames (the latter shouldn't even come up from
+	 * it to mac80211 since they're handled.)
+	 */
+	if (sdata->local->hw.flags & IEEE80211_HW_AP_LINK_PS)
+		return RX_CONTINUE;
+
+	/*
+	 * Don't do anything if the station isn't already asleep. In
+	 * the uAPSD case, the station will probably be marked asleep,
+	 * in the PS-Poll case the station must be confused ...
+	 */
+	if (!test_sta_flag(rx->sta, WLAN_STA_PS_STA))
+		return RX_CONTINUE;
+
+	if (unlikely(ieee80211_is_pspoll(hdr->frame_control))) {
+		if (!test_sta_flag(rx->sta, WLAN_STA_SP)) {
+			if (!test_sta_flag(rx->sta, WLAN_STA_PS_DRIVER))
+				ieee80211_sta_ps_deliver_poll_response(rx->sta);
+			else
+				set_sta_flag(rx->sta, WLAN_STA_PSPOLL);
+		}
+
+		/* Free PS Poll skb here instead of returning RX_DROP that would
+		 * count as an dropped frame. */
+		dev_kfree_skb(rx->skb);
+
+		return RX_QUEUED;
+	} else if (!ieee80211_has_morefrags(hdr->frame_control) &&
+		   !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
+		   ieee80211_has_pm(hdr->frame_control) &&
+		   (ieee80211_is_data_qos(hdr->frame_control) ||
+		    ieee80211_is_qos_nullfunc(hdr->frame_control))) {
+		tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
+		ac = ieee802_1d_to_ac[tid & 7];
+
+		/*
+		 * If this AC is not trigger-enabled do nothing.
+		 *
+		 * NB: This could/should check a separate bitmap of trigger-
+		 * enabled queues, but for now we only implement uAPSD w/o
+		 * TSPEC changes to the ACs, so they're always the same.
+		 */
+		if (!(rx->sta->sta.uapsd_queues & BIT(ac)))
+			return RX_CONTINUE;
+
+		/* if we are in a service period, do nothing */
+		if (test_sta_flag(rx->sta, WLAN_STA_SP))
+			return RX_CONTINUE;
+
+		if (!test_sta_flag(rx->sta, WLAN_STA_PS_DRIVER))
+			ieee80211_sta_ps_deliver_uapsd(rx->sta);
+		else
+			set_sta_flag(rx->sta, WLAN_STA_UAPSD);
+	}
+
+	return RX_CONTINUE;
+}
+
+static ieee80211_rx_result debug_noinline
+ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
+{
+	struct sta_info *sta = rx->sta;
+	struct sk_buff *skb = rx->skb;
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
+	int i;
+
+	if (!sta)
+		return RX_CONTINUE;
+
+	/*
+	 * Update last_rx only for IBSS packets which are for the current
+	 * BSSID and for station already AUTHORIZED to avoid keeping the
+	 * current IBSS network alive in cases where other STAs start
+	 * using different BSSID. This will also give the station another
+	 * chance to restart the authentication/authorization in case
+	 * something went wrong the first time.
+	 */
+	if (rx->sdata->vif.type == NL80211_IFTYPE_ADHOC) {
+		u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
+						NL80211_IFTYPE_ADHOC);
+		if (ether_addr_equal(bssid, rx->sdata->u.ibss.bssid) &&
+		    test_sta_flag(sta, WLAN_STA_AUTHORIZED)) {
+			sta->last_rx = jiffies;
+			if (ieee80211_is_data(hdr->frame_control) &&
+			    !is_multicast_ether_addr(hdr->addr1)) {
+				sta->last_rx_rate_idx = status->rate_idx;
+				sta->last_rx_rate_flag = status->flag;
+				sta->last_rx_rate_vht_flag = status->vht_flag;
+				sta->last_rx_rate_vht_nss = status->vht_nss;
+			}
+		}
+	} else if (!is_multicast_ether_addr(hdr->addr1)) {
+		/*
+		 * Mesh beacons will update last_rx when if they are found to
+		 * match the current local configuration when processed.
+		 */
+		sta->last_rx = jiffies;
+		if (ieee80211_is_data(hdr->frame_control)) {
+			sta->last_rx_rate_idx = status->rate_idx;
+			sta->last_rx_rate_flag = status->flag;
+			sta->last_rx_rate_vht_flag = status->vht_flag;
+			sta->last_rx_rate_vht_nss = status->vht_nss;
+		}
+	}
+
+	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
+		return RX_CONTINUE;
+
+	if (rx->sdata->vif.type == NL80211_IFTYPE_STATION)
+		ieee80211_sta_rx_notify(rx->sdata, hdr);
+
+	sta->rx_fragments++;
+	sta->rx_bytes += rx->skb->len;
+	if (!(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
+		sta->last_signal = status->signal;
+		ewma_add(&sta->avg_signal, -status->signal);
+	}
+
+	if (status->chains) {
+		sta->chains = status->chains;
+		for (i = 0; i < ARRAY_SIZE(status->chain_signal); i++) {
+			int signal = status->chain_signal[i];
+
+			if (!(status->chains & BIT(i)))
+				continue;
+
+			sta->chain_signal_last[i] = signal;
+			ewma_add(&sta->chain_signal_avg[i], -signal);
+		}
+	}
+
+	/*
+	 * Change STA power saving mode only at the end of a frame
+	 * exchange sequence.
+	 */
+	if (!(sta->local->hw.flags & IEEE80211_HW_AP_LINK_PS) &&
+	    !ieee80211_has_morefrags(hdr->frame_control) &&
+	    !(status->rx_flags & IEEE80211_RX_DEFERRED_RELEASE) &&
+	    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
+	     rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
+	    /* PM bit is only checked in frames where it isn't reserved,
+	     * in AP mode it's reserved in non-bufferable management frames
+	     * (cf. IEEE 802.11-2012 8.2.4.1.7 Power Management field)
+	     */
+	    (!ieee80211_is_mgmt(hdr->frame_control) ||
+	     ieee80211_is_bufferable_mmpdu(hdr->frame_control))) {
+		if (test_sta_flag(sta, WLAN_STA_PS_STA)) {
+			if (!ieee80211_has_pm(hdr->frame_control))
+				sta_ps_end(sta);
+		} else {
+			if (ieee80211_has_pm(hdr->frame_control))
+				sta_ps_start(sta);
+		}
+	}
+
+	/* mesh power save support */
+	if (ieee80211_vif_is_mesh(&rx->sdata->vif))
+		ieee80211_mps_rx_h_sta_process(sta, hdr);
+
+	/*
+	 * Drop (qos-)data::nullfunc frames silently, since they
+	 * are used only to control station power saving mode.
+	 */
+	if (ieee80211_is_nullfunc(hdr->frame_control) ||
+	    ieee80211_is_qos_nullfunc(hdr->frame_control)) {
+		I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
+
+		/*
+		 * If we receive a 4-addr nullfunc frame from a STA
+		 * that was not moved to a 4-addr STA vlan yet send
+		 * the event to userspace and for older hostapd drop
+		 * the frame to the monitor interface.
+		 */
+		if (ieee80211_has_a4(hdr->frame_control) &&
+		    (rx->sdata->vif.type == NL80211_IFTYPE_AP ||
+		     (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
+		      !rx->sdata->u.vlan.sta))) {
+			if (!test_and_set_sta_flag(sta, WLAN_STA_4ADDR_EVENT))
+				cfg80211_rx_unexpected_4addr_frame(
+					rx->sdata->dev, sta->sta.addr,
+					GFP_ATOMIC);
+			return RX_DROP_MONITOR;
+		}
+		/*
+		 * Update counter and free packet here to avoid
+		 * counting this as a dropped packed.
+		 */
+		sta->rx_packets++;
+		dev_kfree_skb(rx->skb);
+		return RX_QUEUED;
+	}
+
+	return RX_CONTINUE;
+} /* ieee80211_rx_h_sta_process */
+
+static ieee80211_rx_result debug_noinline
+ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
+{
+	struct sk_buff *skb = rx->skb;
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
+	int keyidx;
+	int hdrlen;
+	ieee80211_rx_result result = RX_DROP_UNUSABLE;
+	struct ieee80211_key *sta_ptk = NULL;
+	int mmie_keyidx = -1;
+	__le16 fc;
+	const struct ieee80211_cipher_scheme *cs = NULL;
+
+	/*
+	 * Key selection 101
+	 *
+	 * There are four types of keys:
+	 *  - GTK (group keys)
+	 *  - IGTK (group keys for management frames)
+	 *  - PTK (pairwise keys)
+	 *  - STK (station-to-station pairwise keys)
+	 *
+	 * When selecting a key, we have to distinguish between multicast
+	 * (including broadcast) and unicast frames, the latter can only
+	 * use PTKs and STKs while the former always use GTKs and IGTKs.
+	 * Unless, of course, actual WEP keys ("pre-RSNA") are used, then
+	 * unicast frames can also use key indices like GTKs. Hence, if we
+	 * don't have a PTK/STK we check the key index for a WEP key.
+	 *
+	 * Note that in a regular BSS, multicast frames are sent by the
+	 * AP only, associated stations unicast the frame to the AP first
+	 * which then multicasts it on their behalf.
+	 *
+	 * There is also a slight problem in IBSS mode: GTKs are negotiated
+	 * with each station, that is something we don't currently handle.
+	 * The spec seems to expect that one negotiates the same key with
+	 * every station but there's no such requirement; VLANs could be
+	 * possible.
+	 */
+
+	/*
+	 * No point in finding a key and decrypting if the frame is neither
+	 * addressed to us nor a multicast frame.
+	 */
+	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
+		return RX_CONTINUE;
+
+	/* start without a key */
+	rx->key = NULL;
+	fc = hdr->frame_control;
+
+	if (rx->sta) {
+		int keyid = rx->sta->ptk_idx;
+
+		if (ieee80211_has_protected(fc) && rx->sta->cipher_scheme) {
+			cs = rx->sta->cipher_scheme;
+			keyid = iwl80211_get_cs_keyid(cs, rx->skb);
+			if (unlikely(keyid < 0))
+				return RX_DROP_UNUSABLE;
+		}
+		sta_ptk = rcu_dereference(rx->sta->ptk[keyid]);
+	}
+
+	if (!ieee80211_has_protected(fc))
+		mmie_keyidx = ieee80211_get_mmie_keyidx(rx->skb);
+
+	if (!is_multicast_ether_addr(hdr->addr1) && sta_ptk) {
+		rx->key = sta_ptk;
+		if ((status->flag & RX_FLAG_DECRYPTED) &&
+		    (status->flag & RX_FLAG_IV_STRIPPED))
+			return RX_CONTINUE;
+		/* Skip decryption if the frame is not protected. */
+		if (!ieee80211_has_protected(fc))
+			return RX_CONTINUE;
+	} else if (mmie_keyidx >= 0) {
+		/* Broadcast/multicast robust management frame / BIP */
+		if ((status->flag & RX_FLAG_DECRYPTED) &&
+		    (status->flag & RX_FLAG_IV_STRIPPED))
+			return RX_CONTINUE;
+
+		if (mmie_keyidx < NUM_DEFAULT_KEYS ||
+		    mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
+			return RX_DROP_MONITOR; /* unexpected BIP keyidx */
+		if (rx->sta)
+			rx->key = rcu_dereference(rx->sta->gtk[mmie_keyidx]);
+		if (!rx->key)
+			rx->key = rcu_dereference(rx->sdata->keys[mmie_keyidx]);
+	} else if (!ieee80211_has_protected(fc)) {
+		/*
+		 * The frame was not protected, so skip decryption. However, we
+		 * need to set rx->key if there is a key that could have been
+		 * used so that the frame may be dropped if encryption would
+		 * have been expected.
+		 */
+		struct ieee80211_key *key = NULL;
+		struct ieee80211_sub_if_data *sdata = rx->sdata;
+		int i;
+
+		if (ieee80211_is_mgmt(fc) &&
+		    is_multicast_ether_addr(hdr->addr1) &&
+		    (key = rcu_dereference(rx->sdata->default_mgmt_key)))
+			rx->key = key;
+		else {
+			if (rx->sta) {
+				for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
+					key = rcu_dereference(rx->sta->gtk[i]);
+					if (key)
+						break;
+				}
+			}
+			if (!key) {
+				for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
+					key = rcu_dereference(sdata->keys[i]);
+					if (key)
+						break;
+				}
+			}
+			if (key)
+				rx->key = key;
+		}
+		return RX_CONTINUE;
+	} else {
+		u8 keyid;
+
+		/*
+		 * The device doesn't give us the IV so we won't be
+		 * able to look up the key. That's ok though, we
+		 * don't need to decrypt the frame, we just won't
+		 * be able to keep statistics accurate.
+		 * Except for key threshold notifications, should
+		 * we somehow allow the driver to tell us which key
+		 * the hardware used if this flag is set?
+		 */
+		if ((status->flag & RX_FLAG_DECRYPTED) &&
+		    (status->flag & RX_FLAG_IV_STRIPPED))
+			return RX_CONTINUE;
+
+		hdrlen = ieee80211_hdrlen(fc);
+
+		if (cs) {
+			keyidx = iwl80211_get_cs_keyid(cs, rx->skb);
+
+			if (unlikely(keyidx < 0))
+				return RX_DROP_UNUSABLE;
+		} else {
+			if (rx->skb->len < 8 + hdrlen)
+				return RX_DROP_UNUSABLE; /* TODO: count this? */
+			/*
+			 * no need to call ieee80211_wep_get_keyidx,
+			 * it verifies a bunch of things we've done already
+			 */
+			skb_copy_bits(rx->skb, hdrlen + 3, &keyid, 1);
+			keyidx = keyid >> 6;
+		}
+
+		/* check per-station GTK first, if multicast packet */
+		if (is_multicast_ether_addr(hdr->addr1) && rx->sta)
+			rx->key = rcu_dereference(rx->sta->gtk[keyidx]);
+
+		/* if not found, try default key */
+		if (!rx->key) {
+			rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
+
+			/*
+			 * RSNA-protected unicast frames should always be
+			 * sent with pairwise or station-to-station keys,
+			 * but for WEP we allow using a key index as well.
+			 */
+			if (rx->key &&
+			    rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP40 &&
+			    rx->key->conf.cipher != WLAN_CIPHER_SUITE_WEP104 &&
+			    !is_multicast_ether_addr(hdr->addr1))
+				rx->key = NULL;
+		}
+	}
+
+	if (rx->key) {
+		if (unlikely(rx->key->flags & KEY_FLAG_TAINTED))
+			return RX_DROP_MONITOR;
+
+		rx->key->tx_rx_count++;
+		/* TODO: add threshold stuff again */
+	} else {
+		return RX_DROP_MONITOR;
+	}
+
+	switch (rx->key->conf.cipher) {
+	case WLAN_CIPHER_SUITE_WEP40:
+	case WLAN_CIPHER_SUITE_WEP104:
+		result = ieee80211_crypto_wep_decrypt(rx);
+		break;
+	case WLAN_CIPHER_SUITE_TKIP:
+		result = ieee80211_crypto_tkip_decrypt(rx);
+		break;
+	case WLAN_CIPHER_SUITE_CCMP:
+		result = ieee80211_crypto_ccmp_decrypt(rx);
+		break;
+	case WLAN_CIPHER_SUITE_AES_CMAC:
+		result = ieee80211_crypto_aes_cmac_decrypt(rx);
+		break;
+	default:
+		result = ieee80211_crypto_hw_decrypt(rx);
+	}
+
+	/* the hdr variable is invalid after the decrypt handlers */
+
+	/* either the frame has been decrypted or will be dropped */
+	status->flag |= RX_FLAG_DECRYPTED;
+
+	return result;
+}
+
+static inline struct ieee80211_fragment_entry *
+ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
+			 unsigned int frag, unsigned int seq, int rx_queue,
+			 struct sk_buff **skb)
+{
+	struct ieee80211_fragment_entry *entry;
+
+	entry = &sdata->fragments[sdata->fragment_next++];
+	if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
+		sdata->fragment_next = 0;
+
+	if (!skb_queue_empty(&entry->skb_list))
+		__skb_queue_purge(&entry->skb_list);
+
+	__skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
+	*skb = NULL;
+	entry->first_frag_time = jiffies;
+	entry->seq = seq;
+	entry->rx_queue = rx_queue;
+	entry->last_frag = frag;
+	entry->ccmp = 0;
+	entry->extra_len = 0;
+
+	return entry;
+}
+
+static inline struct ieee80211_fragment_entry *
+ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
+			  unsigned int frag, unsigned int seq,
+			  int rx_queue, struct ieee80211_hdr *hdr)
+{
+	struct ieee80211_fragment_entry *entry;
+	int i, idx;
+
+	idx = sdata->fragment_next;
+	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
+		struct ieee80211_hdr *f_hdr;
+
+		idx--;
+		if (idx < 0)
+			idx = IEEE80211_FRAGMENT_MAX - 1;
+
+		entry = &sdata->fragments[idx];
+		if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
+		    entry->rx_queue != rx_queue ||
+		    entry->last_frag + 1 != frag)
+			continue;
+
+		f_hdr = (struct ieee80211_hdr *)entry->skb_list.next->data;
+
+		/*
+		 * Check ftype and addresses are equal, else check next fragment
+		 */
+		if (((hdr->frame_control ^ f_hdr->frame_control) &
+		     cpu_to_le16(IEEE80211_FCTL_FTYPE)) ||
+		    !ether_addr_equal(hdr->addr1, f_hdr->addr1) ||
+		    !ether_addr_equal(hdr->addr2, f_hdr->addr2))
+			continue;
+
+		if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
+			__skb_queue_purge(&entry->skb_list);
+			continue;
+		}
+		return entry;
+	}
+
+	return NULL;
+}
+
+static ieee80211_rx_result debug_noinline
+ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
+{
+	struct ieee80211_hdr *hdr;
+	u16 sc;
+	__le16 fc;
+	unsigned int frag, seq;
+	struct ieee80211_fragment_entry *entry;
+	struct sk_buff *skb;
+	struct ieee80211_rx_status *status;
+
+	hdr = (struct ieee80211_hdr *)rx->skb->data;
+	fc = hdr->frame_control;
+
+	if (ieee80211_is_ctl(fc))
+		return RX_CONTINUE;
+
+	sc = le16_to_cpu(hdr->seq_ctrl);
+	frag = sc & IEEE80211_SCTL_FRAG;
+
+	if (is_multicast_ether_addr(hdr->addr1)) {
+		rx->local->dot11MulticastReceivedFrameCount++;
+		goto out_no_led;
+	}
+
+	if (likely(!ieee80211_has_morefrags(fc) && frag == 0))
+		goto out;
+
+	I802_DEBUG_INC(rx->local->rx_handlers_fragments);
+
+	if (skb_linearize(rx->skb))
+		return RX_DROP_UNUSABLE;
+
+	/*
+	 *  skb_linearize() might change the skb->data and
+	 *  previously cached variables (in this case, hdr) need to
+	 *  be refreshed with the new data.
+	 */
+	hdr = (struct ieee80211_hdr *)rx->skb->data;
+	seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
+
+	if (frag == 0) {
+		/* This is the first fragment of a new frame. */
+		entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
+						 rx->seqno_idx, &(rx->skb));
+		if (rx->key && rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP &&
+		    ieee80211_has_protected(fc)) {
+			int queue = rx->security_idx;
+			/* Store CCMP PN so that we can verify that the next
+			 * fragment has a sequential PN value. */
+			entry->ccmp = 1;
+			memcpy(entry->last_pn,
+			       rx->key->u.ccmp.rx_pn[queue],
+			       IEEE80211_CCMP_PN_LEN);
+		}
+		return RX_QUEUED;
+	}
+
+	/* This is a fragment for a frame that should already be pending in
+	 * fragment cache. Add this fragment to the end of the pending entry.
+	 */
+	entry = ieee80211_reassemble_find(rx->sdata, frag, seq,
+					  rx->seqno_idx, hdr);
+	if (!entry) {
+		I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
+		return RX_DROP_MONITOR;
+	}
+
+	/* Verify that MPDUs within one MSDU have sequential PN values.
+	 * (IEEE 802.11i, 8.3.3.4.5) */
+	if (entry->ccmp) {
+		int i;
+		u8 pn[IEEE80211_CCMP_PN_LEN], *rpn;
+		int queue;
+		if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_CCMP)
+			return RX_DROP_UNUSABLE;
+		memcpy(pn, entry->last_pn, IEEE80211_CCMP_PN_LEN);
+		for (i = IEEE80211_CCMP_PN_LEN - 1; i >= 0; i--) {
+			pn[i]++;
+			if (pn[i])
+				break;
+		}
+		queue = rx->security_idx;
+		rpn = rx->key->u.ccmp.rx_pn[queue];
+		if (memcmp(pn, rpn, IEEE80211_CCMP_PN_LEN))
+			return RX_DROP_UNUSABLE;
+		memcpy(entry->last_pn, pn, IEEE80211_CCMP_PN_LEN);
+	}
+
+	skb_pull(rx->skb, ieee80211_hdrlen(fc));
+	__skb_queue_tail(&entry->skb_list, rx->skb);
+	entry->last_frag = frag;
+	entry->extra_len += rx->skb->len;
+	if (ieee80211_has_morefrags(fc)) {
+		rx->skb = NULL;
+		return RX_QUEUED;
+	}
+
+	rx->skb = __skb_dequeue(&entry->skb_list);
+	if (skb_tailroom(rx->skb) < entry->extra_len) {
+		I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
+		if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
+					      GFP_ATOMIC))) {
+			I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
+			__skb_queue_purge(&entry->skb_list);
+			return RX_DROP_UNUSABLE;
+		}
+	}
+	while ((skb = __skb_dequeue(&entry->skb_list))) {
+		memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
+		dev_kfree_skb(skb);
+	}
+
+	/* Complete frame has been reassembled - process it now */
+	status = IEEE80211_SKB_RXCB(rx->skb);
+	status->rx_flags |= IEEE80211_RX_FRAGMENTED;
+
+ out:
+	ieee80211_led_rx(rx->local);
+ out_no_led:
+	if (rx->sta)
+		rx->sta->rx_packets++;
+	return RX_CONTINUE;
+}
+
+static int ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
+{
+	if (unlikely(!rx->sta || !test_sta_flag(rx->sta, WLAN_STA_AUTHORIZED)))
+		return -EACCES;
+
+	return 0;
+}
+
+static int ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc)
+{
+	struct sk_buff *skb = rx->skb;
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
+
+	/*
+	 * Pass through unencrypted frames if the hardware has
+	 * decrypted them already.
+	 */
+	if (status->flag & RX_FLAG_DECRYPTED)
+		return 0;
+
+	/* Drop unencrypted frames if key is set. */
+	if (unlikely(!ieee80211_has_protected(fc) &&
+		     !ieee80211_is_nullfunc(fc) &&
+		     ieee80211_is_data(fc) &&
+		     (rx->key || rx->sdata->drop_unencrypted)))
+		return -EACCES;
+
+	return 0;
+}
+
+static int ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
+{
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
+	__le16 fc = hdr->frame_control;
+
+	/*
+	 * Pass through unencrypted frames if the hardware has
+	 * decrypted them already.
+	 */
+	if (status->flag & RX_FLAG_DECRYPTED)
+		return 0;
+
+	if (rx->sta && test_sta_flag(rx->sta, WLAN_STA_MFP)) {
+		if (unlikely(!ieee80211_has_protected(fc) &&
+			     ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
+			     rx->key)) {
+			if (ieee80211_is_deauth(fc) ||
+			    ieee80211_is_disassoc(fc))
+				cfg80211_rx_unprot_mlme_mgmt(rx->sdata->dev,
+							     rx->skb->data,
+							     rx->skb->len);
+			return -EACCES;
+		}
+		/* BIP does not use Protected field, so need to check MMIE */
+		if (unlikely(ieee80211_is_multicast_robust_mgmt_frame(rx->skb) &&
+			     ieee80211_get_mmie_keyidx(rx->skb) < 0)) {
+			if (ieee80211_is_deauth(fc) ||
+			    ieee80211_is_disassoc(fc))
+				cfg80211_rx_unprot_mlme_mgmt(rx->sdata->dev,
+							     rx->skb->data,
+							     rx->skb->len);
+			return -EACCES;
+		}
+		/*
+		 * When using MFP, Action frames are not allowed prior to
+		 * having configured keys.
+		 */
+		if (unlikely(ieee80211_is_action(fc) && !rx->key &&
+			     ieee80211_is_robust_mgmt_frame(rx->skb)))
+			return -EACCES;
+	}
+
+	return 0;
+}
+
+static int
+__ieee80211_data_to_8023(struct ieee80211_rx_data *rx, bool *port_control)
+{
+	struct ieee80211_sub_if_data *sdata = rx->sdata;
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
+	bool check_port_control = false;
+	struct ethhdr *ehdr;
+	int ret;
+
+	*port_control = false;
+	if (ieee80211_has_a4(hdr->frame_control) &&
+	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && !sdata->u.vlan.sta)
+		return -1;
+
+	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
+	    !!sdata->u.mgd.use_4addr != !!ieee80211_has_a4(hdr->frame_control)) {
+
+		if (!sdata->u.mgd.use_4addr)
+			return -1;
+		else
+			check_port_control = true;
+	}
+
+	if (is_multicast_ether_addr(hdr->addr1) &&
+	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN && sdata->u.vlan.sta)
+		return -1;
+
+	ret = ieee80211_data_to_8023(rx->skb, sdata->vif.addr, sdata->vif.type);
+	if (ret < 0)
+		return ret;
+
+	ehdr = (struct ethhdr *) rx->skb->data;
+	if (ehdr->h_proto == rx->sdata->control_port_protocol)
+		*port_control = true;
+	else if (check_port_control)
+		return -1;
+
+	return 0;
+}
+
+/*
+ * requires that rx->skb is a frame with ethernet header
+ */
+static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
+{
+	static const u8 pae_group_addr[ETH_ALEN] __aligned(2)
+		= { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x03 };
+	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
+
+	/*
+	 * Allow EAPOL frames to us/the PAE group address regardless
+	 * of whether the frame was encrypted or not.
+	 */
+	if (ehdr->h_proto == rx->sdata->control_port_protocol &&
+	    (ether_addr_equal(ehdr->h_dest, rx->sdata->vif.addr) ||
+	     ether_addr_equal(ehdr->h_dest, pae_group_addr)))
+		return true;
+
+	if (ieee80211_802_1x_port_control(rx) ||
+	    ieee80211_drop_unencrypted(rx, fc))
+		return false;
+
+	return true;
+}
+
+/*
+ * requires that rx->skb is a frame with ethernet header
+ */
+static void
+ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
+{
+	struct ieee80211_sub_if_data *sdata = rx->sdata;
+	struct net_device *dev = sdata->dev;
+	struct sk_buff *skb, *xmit_skb;
+	struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
+	struct sta_info *dsta;
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
+
+	skb = rx->skb;
+	xmit_skb = NULL;
+
+	if ((sdata->vif.type == NL80211_IFTYPE_AP ||
+	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
+	    !(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
+	    (status->rx_flags & IEEE80211_RX_RA_MATCH) &&
+	    (sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
+		if (is_multicast_ether_addr(ehdr->h_dest)) {
+			/*
+			 * send multicast frames both to higher layers in
+			 * local net stack and back to the wireless medium
+			 */
+			xmit_skb = skb_copy(skb, GFP_ATOMIC);
+			if (!xmit_skb)
+				net_info_ratelimited("%s: failed to clone multicast frame\n",
+						    dev->name);
+		} else {
+			dsta = sta_info_get(sdata, skb->data);
+			if (dsta) {
+				/*
+				 * The destination station is associated to
+				 * this AP (in this VLAN), so send the frame
+				 * directly to it and do not pass it to local
+				 * net stack.
+				 */
+				xmit_skb = skb;
+				skb = NULL;
+			}
+		}
+	}
+
+#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
+	if (skb) {
+		/* 'align' will only take the values 0 or 2 here since all
+		 * frames are required to be aligned to 2-byte boundaries
+		 * when being passed to mac80211; the code here works just
+		 * as well if that isn't true, but mac80211 assumes it can
+		 * access fields as 2-byte aligned (e.g. for ether_addr_equal)
+		 */
+		int align;
+
+		align = (unsigned long)(skb->data + sizeof(struct ethhdr)) & 3;
+		if (align) {
+			if (WARN_ON(skb_headroom(skb) < 3)) {
+				dev_kfree_skb(skb);
+				skb = NULL;
+			} else {
+				u8 *data = skb->data;
+				size_t len = skb_headlen(skb);
+				skb->data -= align;
+				memmove(skb->data, data, len);
+				skb_set_tail_pointer(skb, len);
+			}
+		}
+	}
+#endif
+
+	if (skb) {
+		/* deliver to local stack */
+		skb->protocol = eth_type_trans(skb, dev);
+		memset(skb->cb, 0, sizeof(skb->cb));
+		if (rx->local->napi)
+			napi_gro_receive(rx->local->napi, skb);
+		else
+			netif_receive_skb(skb);
+	}
+
+	if (xmit_skb) {
+		/*
+		 * Send to wireless media and increase priority by 256 to
+		 * keep the received priority instead of reclassifying
+		 * the frame (see cfg80211_classify8021d).
+		 */
+		xmit_skb->priority += 256;
+		xmit_skb->protocol = htons(ETH_P_802_3);
+		skb_reset_network_header(xmit_skb);
+		skb_reset_mac_header(xmit_skb);
+		dev_queue_xmit(xmit_skb);
+	}
+}
+
+static ieee80211_rx_result debug_noinline
+ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
+{
+	struct net_device *dev = rx->sdata->dev;
+	struct sk_buff *skb = rx->skb;
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
+	__le16 fc = hdr->frame_control;
+	struct sk_buff_head frame_list;
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
+
+	if (unlikely(!ieee80211_is_data(fc)))
+		return RX_CONTINUE;
+
+	if (unlikely(!ieee80211_is_data_present(fc)))
+		return RX_DROP_MONITOR;
+
+	if (!(status->rx_flags & IEEE80211_RX_AMSDU))
+		return RX_CONTINUE;
+
+	if (ieee80211_has_a4(hdr->frame_control) &&
+	    rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
+	    !rx->sdata->u.vlan.sta)
+		return RX_DROP_UNUSABLE;
+
+	if (is_multicast_ether_addr(hdr->addr1) &&
+	    ((rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
+	      rx->sdata->u.vlan.sta) ||
+	     (rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
+	      rx->sdata->u.mgd.use_4addr)))
+		return RX_DROP_UNUSABLE;
+
+	skb->dev = dev;
+	__skb_queue_head_init(&frame_list);
+
+	if (skb_linearize(skb))
+		return RX_DROP_UNUSABLE;
+
+	ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
+				 rx->sdata->vif.type,
+				 rx->local->hw.extra_tx_headroom, true);
+
+	while (!skb_queue_empty(&frame_list)) {
+		rx->skb = __skb_dequeue(&frame_list);
+
+		if (!ieee80211_frame_allowed(rx, fc)) {
+			dev_kfree_skb(rx->skb);
+			continue;
+		}
+		dev->stats.rx_packets++;
+		dev->stats.rx_bytes += rx->skb->len;
+
+		ieee80211_deliver_skb(rx);
+	}
+
+	return RX_QUEUED;
+}
+
+#ifdef CONFIG_MAC80211_MESH
+static ieee80211_rx_result
+ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx)
+{
+	struct ieee80211_hdr *fwd_hdr, *hdr;
+	struct ieee80211_tx_info *info;
+	struct ieee80211s_hdr *mesh_hdr;
+	struct sk_buff *skb = rx->skb, *fwd_skb;
+	struct ieee80211_local *local = rx->local;
+	struct ieee80211_sub_if_data *sdata = rx->sdata;
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
+	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
+	u16 q, hdrlen;
+
+	hdr = (struct ieee80211_hdr *) skb->data;
+	hdrlen = ieee80211_hdrlen(hdr->frame_control);
+
+	/* make sure fixed part of mesh header is there, also checks skb len */
+	if (!pskb_may_pull(rx->skb, hdrlen + 6))
+		return RX_DROP_MONITOR;
+
+	mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
+
+	/* make sure full mesh header is there, also checks skb len */
+	if (!pskb_may_pull(rx->skb,
+			   hdrlen + ieee80211_get_mesh_hdrlen(mesh_hdr)))
+		return RX_DROP_MONITOR;
+
+	/* reload pointers */
+	hdr = (struct ieee80211_hdr *) skb->data;
+	mesh_hdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
+
+	if (ieee80211_drop_unencrypted(rx, hdr->frame_control))
+		return RX_DROP_MONITOR;
+
+	/* frame is in RMC, don't forward */
+	if (ieee80211_is_data(hdr->frame_control) &&
+	    is_multicast_ether_addr(hdr->addr1) &&
+	    mesh_rmc_check(rx->sdata, hdr->addr3, mesh_hdr))
+		return RX_DROP_MONITOR;
+
+	if (!ieee80211_is_data(hdr->frame_control) ||
+	    !(status->rx_flags & IEEE80211_RX_RA_MATCH))
+		return RX_CONTINUE;
+
+	if (!mesh_hdr->ttl)
+		return RX_DROP_MONITOR;
+
+	if (mesh_hdr->flags & MESH_FLAGS_AE) {
+		struct mesh_path *mppath;
+		char *proxied_addr;
+		char *mpp_addr;
+
+		if (is_multicast_ether_addr(hdr->addr1)) {
+			mpp_addr = hdr->addr3;
+			proxied_addr = mesh_hdr->eaddr1;
+		} else if (mesh_hdr->flags & MESH_FLAGS_AE_A5_A6) {
+			/* has_a4 already checked in ieee80211_rx_mesh_check */
+			mpp_addr = hdr->addr4;
+			proxied_addr = mesh_hdr->eaddr2;
+		} else {
+			return RX_DROP_MONITOR;
+		}
+
+		rcu_read_lock();
+		mppath = mpp_path_lookup(sdata, proxied_addr);
+		if (!mppath) {
+			mpp_path_add(sdata, proxied_addr, mpp_addr);
+		} else {
+			spin_lock_bh(&mppath->state_lock);
+			if (!ether_addr_equal(mppath->mpp, mpp_addr))
+				memcpy(mppath->mpp, mpp_addr, ETH_ALEN);
+			spin_unlock_bh(&mppath->state_lock);
+		}
+		rcu_read_unlock();
+	}
+
+	/* Frame has reached destination.  Don't forward */
+	if (!is_multicast_ether_addr(hdr->addr1) &&
+	    ether_addr_equal(sdata->vif.addr, hdr->addr3))
+		return RX_CONTINUE;
+
+	q = ieee80211_select_queue_80211(sdata, skb, hdr);
+	if (ieee80211_queue_stopped(&local->hw, q)) {
+		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_congestion);
+		return RX_DROP_MONITOR;
+	}
+	skb_set_queue_mapping(skb, q);
+
+	if (!--mesh_hdr->ttl) {
+		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_ttl);
+		goto out;
+	}
+
+	if (!ifmsh->mshcfg.dot11MeshForwarding)
+		goto out;
+
+	fwd_skb = skb_copy(skb, GFP_ATOMIC);
+	if (!fwd_skb) {
+		net_info_ratelimited("%s: failed to clone mesh frame\n",
+				    sdata->name);
+		goto out;
+	}
+
+	fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;
+	fwd_hdr->frame_control &= ~cpu_to_le16(IEEE80211_FCTL_RETRY);
+	info = IEEE80211_SKB_CB(fwd_skb);
+	memset(info, 0, sizeof(*info));
+	info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
+	info->control.vif = &rx->sdata->vif;
+	info->control.jiffies = jiffies;
+	if (is_multicast_ether_addr(fwd_hdr->addr1)) {
+		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_mcast);
+		memcpy(fwd_hdr->addr2, sdata->vif.addr, ETH_ALEN);
+		/* update power mode indication when forwarding */
+		ieee80211_mps_set_frame_flags(sdata, NULL, fwd_hdr);
+	} else if (!mesh_nexthop_lookup(sdata, fwd_skb)) {
+		/* mesh power mode flags updated in mesh_nexthop_lookup */
+		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_unicast);
+	} else {
+		/* unable to resolve next hop */
+		mesh_path_error_tx(sdata, ifmsh->mshcfg.element_ttl,
+				   fwd_hdr->addr3, 0,
+				   WLAN_REASON_MESH_PATH_NOFORWARD,
+				   fwd_hdr->addr2);
+		IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, dropped_frames_no_route);
+		kfree_skb(fwd_skb);
+		return RX_DROP_MONITOR;
+	}
+
+	IEEE80211_IFSTA_MESH_CTR_INC(ifmsh, fwded_frames);
+	ieee80211_add_pending_skb(local, fwd_skb);
+ out:
+	if (is_multicast_ether_addr(hdr->addr1) ||
+	    sdata->dev->flags & IFF_PROMISC)
+		return RX_CONTINUE;
+	else
+		return RX_DROP_MONITOR;
+}
+#endif
+
+static ieee80211_rx_result debug_noinline
+ieee80211_rx_h_data(struct ieee80211_rx_data *rx)
+{
+	struct ieee80211_sub_if_data *sdata = rx->sdata;
+	struct ieee80211_local *local = rx->local;
+	struct net_device *dev = sdata->dev;
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
+	__le16 fc = hdr->frame_control;
+	bool port_control;
+	int err;
+
+	if (unlikely(!ieee80211_is_data(hdr->frame_control)))
+		return RX_CONTINUE;
+
+	if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
+		return RX_DROP_MONITOR;
+
+	/*
+	 * Send unexpected-4addr-frame event to hostapd. For older versions,
+	 * also drop the frame to cooked monitor interfaces.
+	 */
+	if (ieee80211_has_a4(hdr->frame_control) &&
+	    sdata->vif.type == NL80211_IFTYPE_AP) {
+		if (rx->sta &&
+		    !test_and_set_sta_flag(rx->sta, WLAN_STA_4ADDR_EVENT))
+			cfg80211_rx_unexpected_4addr_frame(
+				rx->sdata->dev, rx->sta->sta.addr, GFP_ATOMIC);
+		return RX_DROP_MONITOR;
+	}
+
+	err = __ieee80211_data_to_8023(rx, &port_control);
+	if (unlikely(err))
+		return RX_DROP_UNUSABLE;
+
+	if (!ieee80211_frame_allowed(rx, fc))
+		return RX_DROP_MONITOR;
+
+	if (rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
+	    unlikely(port_control) && sdata->bss) {
+		sdata = container_of(sdata->bss, struct ieee80211_sub_if_data,
+				     u.ap);
+		dev = sdata->dev;
+		rx->sdata = sdata;
+	}
+
+	rx->skb->dev = dev;
+
+	dev->stats.rx_packets++;
+	dev->stats.rx_bytes += rx->skb->len;
+
+	if (local->ps_sdata && local->hw.conf.dynamic_ps_timeout > 0 &&
+	    !is_multicast_ether_addr(
+		    ((struct ethhdr *)rx->skb->data)->h_dest) &&
+	    (!local->scanning &&
+	     !test_bit(SDATA_STATE_OFFCHANNEL, &sdata->state))) {
+			mod_timer(&local->dynamic_ps_timer, jiffies +
+			 msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
+	}
+
+	ieee80211_deliver_skb(rx);
+
+	return RX_QUEUED;
+}
+
+static ieee80211_rx_result debug_noinline
+ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx, struct sk_buff_head *frames)
+{
+	struct sk_buff *skb = rx->skb;
+	struct ieee80211_bar *bar = (struct ieee80211_bar *)skb->data;
+	struct tid_ampdu_rx *tid_agg_rx;
+	u16 start_seq_num;
+	u16 tid;
+
+	if (likely(!ieee80211_is_ctl(bar->frame_control)))
+		return RX_CONTINUE;
+
+	if (ieee80211_is_back_req(bar->frame_control)) {
+		struct {
+			__le16 control, start_seq_num;
+		} __packed bar_data;
+
+		if (!rx->sta)
+			return RX_DROP_MONITOR;
+
+		if (skb_copy_bits(skb, offsetof(struct ieee80211_bar, control),
+				  &bar_data, sizeof(bar_data)))
+			return RX_DROP_MONITOR;
+
+		tid = le16_to_cpu(bar_data.control) >> 12;
+
+		tid_agg_rx = rcu_dereference(rx->sta->ampdu_mlme.tid_rx[tid]);
+		if (!tid_agg_rx)
+			return RX_DROP_MONITOR;
+
+		start_seq_num = le16_to_cpu(bar_data.start_seq_num) >> 4;
+
+		/* reset session timer */
+		if (tid_agg_rx->timeout)
+			mod_timer(&tid_agg_rx->session_timer,
+				  TU_TO_EXP_TIME(tid_agg_rx->timeout));
+
+		spin_lock(&tid_agg_rx->reorder_lock);
+		/* release stored frames up to start of BAR */
+		ieee80211_release_reorder_frames(rx->sdata, tid_agg_rx,
+						 start_seq_num, frames);
+		spin_unlock(&tid_agg_rx->reorder_lock);
+
+		kfree_skb(skb);
+		return RX_QUEUED;
+	}
+
+	/*
+	 * After this point, we only want management frames,
+	 * so we can drop all remaining control frames to
+	 * cooked monitor interfaces.
+	 */
+	return RX_DROP_MONITOR;
+}
+
+static void ieee80211_process_sa_query_req(struct ieee80211_sub_if_data *sdata,
+					   struct ieee80211_mgmt *mgmt,
+					   size_t len)
+{
+	struct ieee80211_local *local = sdata->local;
+	struct sk_buff *skb;
+	struct ieee80211_mgmt *resp;
+
+	if (!ether_addr_equal(mgmt->da, sdata->vif.addr)) {
+		/* Not to own unicast address */
+		return;
+	}
+
+	if (!ether_addr_equal(mgmt->sa, sdata->u.mgd.bssid) ||
+	    !ether_addr_equal(mgmt->bssid, sdata->u.mgd.bssid)) {
+		/* Not from the current AP or not associated yet. */
+		return;
+	}
+
+	if (len < 24 + 1 + sizeof(resp->u.action.u.sa_query)) {
+		/* Too short SA Query request frame */
+		return;
+	}
+
+	skb = dev_alloc_skb(sizeof(*resp) + local->hw.extra_tx_headroom);
+	if (skb == NULL)
+		return;
+
+	skb_reserve(skb, local->hw.extra_tx_headroom);
+	resp = (struct ieee80211_mgmt *) skb_put(skb, 24);
+	memset(resp, 0, 24);
+	memcpy(resp->da, mgmt->sa, ETH_ALEN);
+	memcpy(resp->sa, sdata->vif.addr, ETH_ALEN);
+	memcpy(resp->bssid, sdata->u.mgd.bssid, ETH_ALEN);
+	resp->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
+					  IEEE80211_STYPE_ACTION);
+	skb_put(skb, 1 + sizeof(resp->u.action.u.sa_query));
+	resp->u.action.category = WLAN_CATEGORY_SA_QUERY;
+	resp->u.action.u.sa_query.action = WLAN_ACTION_SA_QUERY_RESPONSE;
+	memcpy(resp->u.action.u.sa_query.trans_id,
+	       mgmt->u.action.u.sa_query.trans_id,
+	       WLAN_SA_QUERY_TR_ID_LEN);
+
+	ieee80211_tx_skb(sdata, skb);
+}
+
+static ieee80211_rx_result debug_noinline
+ieee80211_rx_h_mgmt_check(struct ieee80211_rx_data *rx)
+{
+	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
+
+	/*
+	 * From here on, look only at management frames.
+	 * Data and control frames are already handled,
+	 * and unknown (reserved) frames are useless.
+	 */
+	if (rx->skb->len < 24)
+		return RX_DROP_MONITOR;
+
+	if (!ieee80211_is_mgmt(mgmt->frame_control))
+		return RX_DROP_MONITOR;
+
+	if (rx->sdata->vif.type == NL80211_IFTYPE_AP &&
+	    ieee80211_is_beacon(mgmt->frame_control) &&
+	    !(rx->flags & IEEE80211_RX_BEACON_REPORTED)) {
+		int sig = 0;
+
+		if (rx->local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
+			sig = status->signal;
+
+		cfg80211_report_obss_beacon(rx->local->hw.wiphy,
+					    rx->skb->data, rx->skb->len,
+					    status->freq, sig);
+		rx->flags |= IEEE80211_RX_BEACON_REPORTED;
+	}
+
+	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
+		return RX_DROP_MONITOR;
+
+	if (ieee80211_drop_unencrypted_mgmt(rx))
+		return RX_DROP_UNUSABLE;
+
+	return RX_CONTINUE;
+}
+
+static ieee80211_rx_result debug_noinline
+ieee80211_rx_h_action(struct ieee80211_rx_data *rx)
+{
+	struct ieee80211_local *local = rx->local;
+	struct ieee80211_sub_if_data *sdata = rx->sdata;
+	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
+	int len = rx->skb->len;
+
+	if (!ieee80211_is_action(mgmt->frame_control))
+		return RX_CONTINUE;
+
+	/* drop too small frames */
+	if (len < IEEE80211_MIN_ACTION_SIZE)
+		return RX_DROP_UNUSABLE;
+
+	if (!rx->sta && mgmt->u.action.category != WLAN_CATEGORY_PUBLIC &&
+	    mgmt->u.action.category != WLAN_CATEGORY_SELF_PROTECTED &&
+	    mgmt->u.action.category != WLAN_CATEGORY_SPECTRUM_MGMT)
+		return RX_DROP_UNUSABLE;
+
+	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
+		return RX_DROP_UNUSABLE;
+
+	switch (mgmt->u.action.category) {
+	case WLAN_CATEGORY_HT:
+		/* reject HT action frames from stations not supporting HT */
+		if (!rx->sta->sta.ht_cap.ht_supported)
+			goto invalid;
+
+		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
+		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
+		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
+		    sdata->vif.type != NL80211_IFTYPE_AP &&
+		    sdata->vif.type != NL80211_IFTYPE_ADHOC)
+			break;
+
+		/* verify action & smps_control/chanwidth are present */
+		if (len < IEEE80211_MIN_ACTION_SIZE + 2)
+			goto invalid;
+
+		switch (mgmt->u.action.u.ht_smps.action) {
+		case WLAN_HT_ACTION_SMPS: {
+			struct ieee80211_supported_band *sband;
+			enum ieee80211_smps_mode smps_mode;
+
+			/* convert to HT capability */
+			switch (mgmt->u.action.u.ht_smps.smps_control) {
+			case WLAN_HT_SMPS_CONTROL_DISABLED:
+				smps_mode = IEEE80211_SMPS_OFF;
+				break;
+			case WLAN_HT_SMPS_CONTROL_STATIC:
+				smps_mode = IEEE80211_SMPS_STATIC;
+				break;
+			case WLAN_HT_SMPS_CONTROL_DYNAMIC:
+				smps_mode = IEEE80211_SMPS_DYNAMIC;
+				break;
+			default:
+				goto invalid;
+			}
+
+			/* if no change do nothing */
+			if (rx->sta->sta.smps_mode == smps_mode)
+				goto handled;
+			rx->sta->sta.smps_mode = smps_mode;
+
+			sband = rx->local->hw.wiphy->bands[status->band];
+
+			rate_control_rate_update(local, sband, rx->sta,
+						 IEEE80211_RC_SMPS_CHANGED);
+			goto handled;
+		}
+		case WLAN_HT_ACTION_NOTIFY_CHANWIDTH: {
+			struct ieee80211_supported_band *sband;
+			u8 chanwidth = mgmt->u.action.u.ht_notify_cw.chanwidth;
+			enum ieee80211_sta_rx_bandwidth new_bw;
+
+			/* If it doesn't support 40 MHz it can't change ... */
+			if (!(rx->sta->sta.ht_cap.cap &
+					IEEE80211_HT_CAP_SUP_WIDTH_20_40))
+				goto handled;
+
+			if (chanwidth == IEEE80211_HT_CHANWIDTH_20MHZ)
+				new_bw = IEEE80211_STA_RX_BW_20;
+			else
+				new_bw = ieee80211_sta_cur_vht_bw(rx->sta);
+
+			if (rx->sta->sta.bandwidth == new_bw)
+				goto handled;
+
+			sband = rx->local->hw.wiphy->bands[status->band];
+
+			rate_control_rate_update(local, sband, rx->sta,
+						 IEEE80211_RC_BW_CHANGED);
+			goto handled;
+		}
+		default:
+			goto invalid;
+		}
+
+		break;
+	case WLAN_CATEGORY_PUBLIC:
+		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
+			goto invalid;
+		if (sdata->vif.type != NL80211_IFTYPE_STATION)
+			break;
+		if (!rx->sta)
+			break;
+		if (!ether_addr_equal(mgmt->bssid, sdata->u.mgd.bssid))
+			break;
+		if (mgmt->u.action.u.ext_chan_switch.action_code !=
+				WLAN_PUB_ACTION_EXT_CHANSW_ANN)
+			break;
+		if (len < offsetof(struct ieee80211_mgmt,
+				   u.action.u.ext_chan_switch.variable))
+			goto invalid;
+		goto queue;
+	case WLAN_CATEGORY_VHT:
+		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
+		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
+		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
+		    sdata->vif.type != NL80211_IFTYPE_AP &&
+		    sdata->vif.type != NL80211_IFTYPE_ADHOC)
+			break;
+
+		/* verify action code is present */
+		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
+			goto invalid;
+
+		switch (mgmt->u.action.u.vht_opmode_notif.action_code) {
+		case WLAN_VHT_ACTION_OPMODE_NOTIF: {
+			u8 opmode;
+
+			/* verify opmode is present */
+			if (len < IEEE80211_MIN_ACTION_SIZE + 2)
+				goto invalid;
+
+			opmode = mgmt->u.action.u.vht_opmode_notif.operating_mode;
+
+			ieee80211_vht_handle_opmode(rx->sdata, rx->sta,
+						    opmode, status->band,
+						    false);
+			goto handled;
+		}
+		default:
+			break;
+		}
+		break;
+	case WLAN_CATEGORY_BACK:
+		if (sdata->vif.type != NL80211_IFTYPE_STATION &&
+		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
+		    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
+		    sdata->vif.type != NL80211_IFTYPE_AP &&
+		    sdata->vif.type != NL80211_IFTYPE_ADHOC)
+			break;
+
+		/* verify action_code is present */
+		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
+			break;
+
+		switch (mgmt->u.action.u.addba_req.action_code) {
+		case WLAN_ACTION_ADDBA_REQ:
+			if (len < (IEEE80211_MIN_ACTION_SIZE +
+				   sizeof(mgmt->u.action.u.addba_req)))
+				goto invalid;
+			break;
+		case WLAN_ACTION_ADDBA_RESP:
+			if (len < (IEEE80211_MIN_ACTION_SIZE +
+				   sizeof(mgmt->u.action.u.addba_resp)))
+				goto invalid;
+			break;
+		case WLAN_ACTION_DELBA:
+			if (len < (IEEE80211_MIN_ACTION_SIZE +
+				   sizeof(mgmt->u.action.u.delba)))
+				goto invalid;
+			break;
+		default:
+			goto invalid;
+		}
+
+		goto queue;
+	case WLAN_CATEGORY_SPECTRUM_MGMT:
+		/* verify action_code is present */
+		if (len < IEEE80211_MIN_ACTION_SIZE + 1)
+			break;
+
+		switch (mgmt->u.action.u.measurement.action_code) {
+		case WLAN_ACTION_SPCT_MSR_REQ:
+			if (status->band != IEEE80211_BAND_5GHZ)
+				break;
+
+			if (len < (IEEE80211_MIN_ACTION_SIZE +
+				   sizeof(mgmt->u.action.u.measurement)))
+				break;
+
+			if (sdata->vif.type != NL80211_IFTYPE_STATION)
+				break;
+
+			ieee80211_process_measurement_req(sdata, mgmt, len);
+			goto handled;
+		case WLAN_ACTION_SPCT_CHL_SWITCH: {
+			u8 *bssid;
+			if (len < (IEEE80211_MIN_ACTION_SIZE +
+				   sizeof(mgmt->u.action.u.chan_switch)))
+				break;
+
+			if (sdata->vif.type != NL80211_IFTYPE_STATION &&
+			    sdata->vif.type != NL80211_IFTYPE_ADHOC &&
+			    sdata->vif.type != NL80211_IFTYPE_MESH_POINT)
+				break;
+
+			if (sdata->vif.type == NL80211_IFTYPE_STATION)
+				bssid = sdata->u.mgd.bssid;
+			else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
+				bssid = sdata->u.ibss.bssid;
+			else if (sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
+				bssid = mgmt->sa;
+			else
+				break;
+
+			if (!ether_addr_equal(mgmt->bssid, bssid))
+				break;
+
+			goto queue;
+			}
+		}
+		break;
+	case WLAN_CATEGORY_SA_QUERY:
+		if (len < (IEEE80211_MIN_ACTION_SIZE +
+			   sizeof(mgmt->u.action.u.sa_query)))
+			break;
+
+		switch (mgmt->u.action.u.sa_query.action) {
+		case WLAN_ACTION_SA_QUERY_REQUEST:
+			if (sdata->vif.type != NL80211_IFTYPE_STATION)
+				break;
+			ieee80211_process_sa_query_req(sdata, mgmt, len);
+			goto handled;
+		}
+		break;
+	case WLAN_CATEGORY_SELF_PROTECTED:
+		if (len < (IEEE80211_MIN_ACTION_SIZE +
+			   sizeof(mgmt->u.action.u.self_prot.action_code)))
+			break;
+
+		switch (mgmt->u.action.u.self_prot.action_code) {
+		case WLAN_SP_MESH_PEERING_OPEN:
+		case WLAN_SP_MESH_PEERING_CLOSE:
+		case WLAN_SP_MESH_PEERING_CONFIRM:
+			if (!ieee80211_vif_is_mesh(&sdata->vif))
+				goto invalid;
+			if (sdata->u.mesh.user_mpm)
+				/* userspace handles this frame */
+				break;
+			goto queue;
+		case WLAN_SP_MGK_INFORM:
+		case WLAN_SP_MGK_ACK:
+			if (!ieee80211_vif_is_mesh(&sdata->vif))
+				goto invalid;
+			break;
+		}
+		break;
+	case WLAN_CATEGORY_MESH_ACTION:
+		if (len < (IEEE80211_MIN_ACTION_SIZE +
+			   sizeof(mgmt->u.action.u.mesh_action.action_code)))
+			break;
+
+		if (!ieee80211_vif_is_mesh(&sdata->vif))
+			break;
+		if (mesh_action_is_path_sel(mgmt) &&
+		    !mesh_path_sel_is_hwmp(sdata))
+			break;
+		goto queue;
+	}
+
+	return RX_CONTINUE;
+
+ invalid:
+	status->rx_flags |= IEEE80211_RX_MALFORMED_ACTION_FRM;
+	/* will return in the next handlers */
+	return RX_CONTINUE;
+
+ handled:
+	if (rx->sta)
+		rx->sta->rx_packets++;
+	dev_kfree_skb(rx->skb);
+	return RX_QUEUED;
+
+ queue:
+	rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
+	skb_queue_tail(&sdata->skb_queue, rx->skb);
+	ieee80211_queue_work(&local->hw, &sdata->work);
+	if (rx->sta)
+		rx->sta->rx_packets++;
+	return RX_QUEUED;
+}
+
+static ieee80211_rx_result debug_noinline
+ieee80211_rx_h_userspace_mgmt(struct ieee80211_rx_data *rx)
+{
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
+	int sig = 0;
+
+	/* skip known-bad action frames and return them in the next handler */
+	if (status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM)
+		return RX_CONTINUE;
+
+	/*
+	 * Getting here means the kernel doesn't know how to handle
+	 * it, but maybe userspace does ... include returned frames
+	 * so userspace can register for those to know whether ones
+	 * it transmitted were processed or returned.
+	 */
+
+	if (rx->local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
+		sig = status->signal;
+
+	if (cfg80211_rx_mgmt(&rx->sdata->wdev, status->freq, sig,
+			     rx->skb->data, rx->skb->len, 0)) {
+		if (rx->sta)
+			rx->sta->rx_packets++;
+		dev_kfree_skb(rx->skb);
+		return RX_QUEUED;
+	}
+
+	return RX_CONTINUE;
+}
+
+static ieee80211_rx_result debug_noinline
+ieee80211_rx_h_action_return(struct ieee80211_rx_data *rx)
+{
+	struct ieee80211_local *local = rx->local;
+	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) rx->skb->data;
+	struct sk_buff *nskb;
+	struct ieee80211_sub_if_data *sdata = rx->sdata;
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
+
+	if (!ieee80211_is_action(mgmt->frame_control))
+		return RX_CONTINUE;
+
+	/*
+	 * For AP mode, hostapd is responsible for handling any action
+	 * frames that we didn't handle, including returning unknown
+	 * ones. For all other modes we will return them to the sender,
+	 * setting the 0x80 bit in the action category, as required by
+	 * 802.11-2012 9.24.4.
+	 * Newer versions of hostapd shall also use the management frame
+	 * registration mechanisms, but older ones still use cooked
+	 * monitor interfaces so push all frames there.
+	 */
+	if (!(status->rx_flags & IEEE80211_RX_MALFORMED_ACTION_FRM) &&
+	    (sdata->vif.type == NL80211_IFTYPE_AP ||
+	     sdata->vif.type == NL80211_IFTYPE_AP_VLAN))
+		return RX_DROP_MONITOR;
+
+	if (is_multicast_ether_addr(mgmt->da))
+		return RX_DROP_MONITOR;
+
+	/* do not return rejected action frames */
+	if (mgmt->u.action.category & 0x80)
+		return RX_DROP_UNUSABLE;
+
+	nskb = skb_copy_expand(rx->skb, local->hw.extra_tx_headroom, 0,
+			       GFP_ATOMIC);
+	if (nskb) {
+		struct ieee80211_mgmt *nmgmt = (void *)nskb->data;
+
+		nmgmt->u.action.category |= 0x80;
+		memcpy(nmgmt->da, nmgmt->sa, ETH_ALEN);
+		memcpy(nmgmt->sa, rx->sdata->vif.addr, ETH_ALEN);
+
+		memset(nskb->cb, 0, sizeof(nskb->cb));
+
+		if (rx->sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE) {
+			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(nskb);
+
+			info->flags = IEEE80211_TX_CTL_TX_OFFCHAN |
+				      IEEE80211_TX_INTFL_OFFCHAN_TX_OK |
+				      IEEE80211_TX_CTL_NO_CCK_RATE;
+			if (local->hw.flags & IEEE80211_HW_QUEUE_CONTROL)
+				info->hw_queue =
+					local->hw.offchannel_tx_hw_queue;
+		}
+
+		__ieee80211_tx_skb_tid_band(rx->sdata, nskb, 7,
+					    status->band);
+	}
+	dev_kfree_skb(rx->skb);
+	return RX_QUEUED;
+}
+
+static ieee80211_rx_result debug_noinline
+ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
+{
+	struct ieee80211_sub_if_data *sdata = rx->sdata;
+	struct ieee80211_mgmt *mgmt = (void *)rx->skb->data;
+	__le16 stype;
+
+	stype = mgmt->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE);
+
+	if (!ieee80211_vif_is_mesh(&sdata->vif) &&
+	    sdata->vif.type != NL80211_IFTYPE_ADHOC &&
+	    sdata->vif.type != NL80211_IFTYPE_STATION)
+		return RX_DROP_MONITOR;
+
+	switch (stype) {
+	case cpu_to_le16(IEEE80211_STYPE_AUTH):
+	case cpu_to_le16(IEEE80211_STYPE_BEACON):
+	case cpu_to_le16(IEEE80211_STYPE_PROBE_RESP):
+		/* process for all: mesh, mlme, ibss */
+		break;
+	case cpu_to_le16(IEEE80211_STYPE_ASSOC_RESP):
+	case cpu_to_le16(IEEE80211_STYPE_REASSOC_RESP):
+	case cpu_to_le16(IEEE80211_STYPE_DEAUTH):
+	case cpu_to_le16(IEEE80211_STYPE_DISASSOC):
+		if (is_multicast_ether_addr(mgmt->da) &&
+		    !is_broadcast_ether_addr(mgmt->da))
+			return RX_DROP_MONITOR;
+
+		/* process only for station */
+		if (sdata->vif.type != NL80211_IFTYPE_STATION)
+			return RX_DROP_MONITOR;
+		break;
+	case cpu_to_le16(IEEE80211_STYPE_PROBE_REQ):
+		/* process only for ibss and mesh */
+		if (sdata->vif.type != NL80211_IFTYPE_ADHOC &&
+		    sdata->vif.type != NL80211_IFTYPE_MESH_POINT)
+			return RX_DROP_MONITOR;
+		break;
+	default:
+		return RX_DROP_MONITOR;
+	}
+
+	/* queue up frame and kick off work to process it */
+	rx->skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
+	skb_queue_tail(&sdata->skb_queue, rx->skb);
+	ieee80211_queue_work(&rx->local->hw, &sdata->work);
+	if (rx->sta)
+		rx->sta->rx_packets++;
+
+	return RX_QUEUED;
+}
+
+/* TODO: use IEEE80211_RX_FRAGMENTED */
+static void ieee80211_rx_cooked_monitor(struct ieee80211_rx_data *rx,
+					struct ieee80211_rate *rate)
+{
+	struct ieee80211_sub_if_data *sdata;
+	struct ieee80211_local *local = rx->local;
+	struct sk_buff *skb = rx->skb, *skb2;
+	struct net_device *prev_dev = NULL;
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
+	int needed_headroom;
+
+	/*
+	 * If cooked monitor has been processed already, then
+	 * don't do it again. If not, set the flag.
+	 */
+	if (rx->flags & IEEE80211_RX_CMNTR)
+		goto out_free_skb;
+	rx->flags |= IEEE80211_RX_CMNTR;
+
+	/* If there are no cooked monitor interfaces, just free the SKB */
+	if (!local->cooked_mntrs)
+		goto out_free_skb;
+
+	/* room for the radiotap header based on driver features */
+	needed_headroom = ieee80211_rx_radiotap_space(local, status);
+
+	if (skb_headroom(skb) < needed_headroom &&
+	    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC))
+		goto out_free_skb;
+
+	/* prepend radiotap information */
+	ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom,
+					 false);
+
+	skb_set_mac_header(skb, 0);
+	skb->ip_summed = CHECKSUM_UNNECESSARY;
+	skb->pkt_type = PACKET_OTHERHOST;
+	skb->protocol = htons(ETH_P_802_2);
+
+	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
+		if (!ieee80211_sdata_running(sdata))
+			continue;
+
+		if (sdata->vif.type != NL80211_IFTYPE_MONITOR ||
+		    !(sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES))
+			continue;
+
+		if (prev_dev) {
+			skb2 = skb_clone(skb, GFP_ATOMIC);
+			if (skb2) {
+				skb2->dev = prev_dev;
+				netif_receive_skb(skb2);
+			}
+		}
+
+		prev_dev = sdata->dev;
+		sdata->dev->stats.rx_packets++;
+		sdata->dev->stats.rx_bytes += skb->len;
+	}
+
+	if (prev_dev) {
+		skb->dev = prev_dev;
+		netif_receive_skb(skb);
+		return;
+	}
+
+ out_free_skb:
+	dev_kfree_skb(skb);
+}
+
+static void ieee80211_rx_handlers_result(struct ieee80211_rx_data *rx,
+					 ieee80211_rx_result res)
+{
+	switch (res) {
+	case RX_DROP_MONITOR:
+		I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
+		if (rx->sta)
+			rx->sta->rx_dropped++;
+		/* fall through */
+	case RX_CONTINUE: {
+		struct ieee80211_rate *rate = NULL;
+		struct ieee80211_supported_band *sband;
+		struct ieee80211_rx_status *status;
+
+		status = IEEE80211_SKB_RXCB((rx->skb));
+
+		sband = rx->local->hw.wiphy->bands[status->band];
+		if (!(status->flag & RX_FLAG_HT) &&
+		    !(status->flag & RX_FLAG_VHT))
+			rate = &sband->bitrates[status->rate_idx];
+
+		ieee80211_rx_cooked_monitor(rx, rate);
+		break;
+		}
+	case RX_DROP_UNUSABLE:
+		I802_DEBUG_INC(rx->sdata->local->rx_handlers_drop);
+		if (rx->sta)
+			rx->sta->rx_dropped++;
+		dev_kfree_skb(rx->skb);
+		break;
+	case RX_QUEUED:
+		I802_DEBUG_INC(rx->sdata->local->rx_handlers_queued);
+		break;
+	}
+}
+
+static void ieee80211_rx_handlers(struct ieee80211_rx_data *rx,
+				  struct sk_buff_head *frames)
+{
+	ieee80211_rx_result res = RX_DROP_MONITOR;
+	struct sk_buff *skb;
+
+#define CALL_RXH(rxh)			\
+	do {				\
+		res = rxh(rx);		\
+		if (res != RX_CONTINUE)	\
+			goto rxh_next;  \
+	} while (0);
+
+	spin_lock_bh(&rx->local->rx_path_lock);
+
+	while ((skb = __skb_dequeue(frames))) {
+		/*
+		 * all the other fields are valid across frames
+		 * that belong to an aMPDU since they are on the
+		 * same TID from the same station
+		 */
+		rx->skb = skb;
+
+		CALL_RXH(ieee80211_rx_h_check_more_data)
+		CALL_RXH(ieee80211_rx_h_uapsd_and_pspoll)
+		CALL_RXH(ieee80211_rx_h_sta_process)
+		CALL_RXH(ieee80211_rx_h_decrypt)
+		CALL_RXH(ieee80211_rx_h_defragment)
+		CALL_RXH(ieee80211_rx_h_michael_mic_verify)
+		/* must be after MMIC verify so header is counted in MPDU mic */
+#ifdef CONFIG_MAC80211_MESH
+		if (ieee80211_vif_is_mesh(&rx->sdata->vif))
+			CALL_RXH(ieee80211_rx_h_mesh_fwding);
+#endif
+		CALL_RXH(ieee80211_rx_h_amsdu)
+		CALL_RXH(ieee80211_rx_h_data)
+
+		/* special treatment -- needs the queue */
+		res = ieee80211_rx_h_ctrl(rx, frames);
+		if (res != RX_CONTINUE)
+			goto rxh_next;
+
+		CALL_RXH(ieee80211_rx_h_mgmt_check)
+		CALL_RXH(ieee80211_rx_h_action)
+		CALL_RXH(ieee80211_rx_h_userspace_mgmt)
+		CALL_RXH(ieee80211_rx_h_action_return)
+		CALL_RXH(ieee80211_rx_h_mgmt)
+
+ rxh_next:
+		ieee80211_rx_handlers_result(rx, res);
+
+#undef CALL_RXH
+	}
+
+	spin_unlock_bh(&rx->local->rx_path_lock);
+}
+
+static void ieee80211_invoke_rx_handlers(struct ieee80211_rx_data *rx)
+{
+	struct sk_buff_head reorder_release;
+	ieee80211_rx_result res = RX_DROP_MONITOR;
+
+	__skb_queue_head_init(&reorder_release);
+
+#define CALL_RXH(rxh)			\
+	do {				\
+		res = rxh(rx);		\
+		if (res != RX_CONTINUE)	\
+			goto rxh_next;  \
+	} while (0);
+
+	CALL_RXH(ieee80211_rx_h_check)
+
+	ieee80211_rx_reorder_ampdu(rx, &reorder_release);
+
+	ieee80211_rx_handlers(rx, &reorder_release);
+	return;
+
+ rxh_next:
+	ieee80211_rx_handlers_result(rx, res);
+
+#undef CALL_RXH
+}
+
+/*
+ * This function makes calls into the RX path, therefore
+ * it has to be invoked under RCU read lock.
+ */
+void ieee80211_release_reorder_timeout(struct sta_info *sta, int tid)
+{
+	struct sk_buff_head frames;
+	struct ieee80211_rx_data rx = {
+		.sta = sta,
+		.sdata = sta->sdata,
+		.local = sta->local,
+		/* This is OK -- must be QoS data frame */
+		.security_idx = tid,
+		.seqno_idx = tid,
+		.flags = 0,
+	};
+	struct tid_ampdu_rx *tid_agg_rx;
+
+	tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
+	if (!tid_agg_rx)
+		return;
+
+	__skb_queue_head_init(&frames);
+
+	spin_lock(&tid_agg_rx->reorder_lock);
+	ieee80211_sta_reorder_release(sta->sdata, tid_agg_rx, &frames);
+	spin_unlock(&tid_agg_rx->reorder_lock);
+
+	ieee80211_rx_handlers(&rx, &frames);
+}
+
+/* main receive path */
+
+static bool prepare_for_handlers(struct ieee80211_rx_data *rx,
+				 struct ieee80211_hdr *hdr)
+{
+	struct ieee80211_sub_if_data *sdata = rx->sdata;
+	struct sk_buff *skb = rx->skb;
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
+	u8 *bssid = ieee80211_get_bssid(hdr, skb->len, sdata->vif.type);
+	int multicast = is_multicast_ether_addr(hdr->addr1);
+
+	switch (sdata->vif.type) {
+	case NL80211_IFTYPE_STATION:
+		if (!bssid && !sdata->u.mgd.use_4addr)
+			return false;
+		if (!multicast &&
+		    !ether_addr_equal(sdata->vif.addr, hdr->addr1)) {
+			if (!(sdata->dev->flags & IFF_PROMISC) ||
+			    sdata->u.mgd.use_4addr)
+				return false;
+			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
+		}
+		break;
+	case NL80211_IFTYPE_ADHOC:
+		if (!bssid)
+			return false;
+		if (ether_addr_equal(sdata->vif.addr, hdr->addr2) ||
+		    ether_addr_equal(sdata->u.ibss.bssid, hdr->addr2))
+			return false;
+		if (ieee80211_is_beacon(hdr->frame_control)) {
+			return true;
+		} else if (!ieee80211_bssid_match(bssid, sdata->u.ibss.bssid)) {
+			return false;
+		} else if (!multicast &&
+			   !ether_addr_equal(sdata->vif.addr, hdr->addr1)) {
+			if (!(sdata->dev->flags & IFF_PROMISC))
+				return false;
+			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
+		} else if (!rx->sta) {
+			int rate_idx;
+			if (status->flag & (RX_FLAG_HT | RX_FLAG_VHT))
+				rate_idx = 0; /* TODO: HT/VHT rates */
+			else
+				rate_idx = status->rate_idx;
+			ieee80211_ibss_rx_no_sta(sdata, bssid, hdr->addr2,
+						 BIT(rate_idx));
+		}
+		break;
+	case NL80211_IFTYPE_MESH_POINT:
+		if (!multicast &&
+		    !ether_addr_equal(sdata->vif.addr, hdr->addr1)) {
+			if (!(sdata->dev->flags & IFF_PROMISC))
+				return false;
+
+			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
+		}
+		break;
+	case NL80211_IFTYPE_AP_VLAN:
+	case NL80211_IFTYPE_AP:
+		if (!bssid) {
+			if (!ether_addr_equal(sdata->vif.addr, hdr->addr1))
+				return false;
+		} else if (!ieee80211_bssid_match(bssid, sdata->vif.addr)) {
+			/*
+			 * Accept public action frames even when the
+			 * BSSID doesn't match, this is used for P2P
+			 * and location updates. Note that mac80211
+			 * itself never looks at these frames.
+			 */
+			if (!multicast &&
+			    !ether_addr_equal(sdata->vif.addr, hdr->addr1))
+				return false;
+			if (ieee80211_is_public_action(hdr, skb->len))
+				return true;
+			if (!ieee80211_is_beacon(hdr->frame_control))
+				return false;
+			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
+		} else if (!ieee80211_has_tods(hdr->frame_control)) {
+			/* ignore data frames to TDLS-peers */
+			if (ieee80211_is_data(hdr->frame_control))
+				return false;
+			/* ignore action frames to TDLS-peers */
+			if (ieee80211_is_action(hdr->frame_control) &&
+			    !ether_addr_equal(bssid, hdr->addr1))
+				return false;
+		}
+		break;
+	case NL80211_IFTYPE_WDS:
+		if (bssid || !ieee80211_is_data(hdr->frame_control))
+			return false;
+		if (!ether_addr_equal(sdata->u.wds.remote_addr, hdr->addr2))
+			return false;
+		break;
+	case NL80211_IFTYPE_P2P_DEVICE:
+		if (!ieee80211_is_public_action(hdr, skb->len) &&
+		    !ieee80211_is_probe_req(hdr->frame_control) &&
+		    !ieee80211_is_probe_resp(hdr->frame_control) &&
+		    !ieee80211_is_beacon(hdr->frame_control))
+			return false;
+		if (!ether_addr_equal(sdata->vif.addr, hdr->addr1) &&
+		    !multicast)
+			status->rx_flags &= ~IEEE80211_RX_RA_MATCH;
+		break;
+	default:
+		/* should never get here */
+		WARN_ON_ONCE(1);
+		break;
+	}
+
+	return true;
+}
+
+/*
+ * This function returns whether or not the SKB
+ * was destined for RX processing or not, which,
+ * if consume is true, is equivalent to whether
+ * or not the skb was consumed.
+ */
+static bool ieee80211_prepare_and_rx_handle(struct ieee80211_rx_data *rx,
+					    struct sk_buff *skb, bool consume)
+{
+	struct ieee80211_local *local = rx->local;
+	struct ieee80211_sub_if_data *sdata = rx->sdata;
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
+	struct ieee80211_hdr *hdr = (void *)skb->data;
+
+	rx->skb = skb;
+	status->rx_flags |= IEEE80211_RX_RA_MATCH;
+
+	if (!prepare_for_handlers(rx, hdr))
+		return false;
+
+	if (!consume) {
+		skb = skb_copy(skb, GFP_ATOMIC);
+		if (!skb) {
+			if (net_ratelimit())
+				wiphy_debug(local->hw.wiphy,
+					"failed to copy skb for %s\n",
+					sdata->name);
+			return true;
+		}
+
+		rx->skb = skb;
+	}
+
+	ieee80211_invoke_rx_handlers(rx);
+	return true;
+}
+
+/*
+ * This is the actual Rx frames handler. as it belongs to Rx path it must
+ * be called with rcu_read_lock protection.
+ */
+static void __ieee80211_rx_handle_packet(struct ieee80211_hw *hw,
+					 struct sk_buff *skb)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+	struct ieee80211_sub_if_data *sdata;
+	struct ieee80211_hdr *hdr;
+	__le16 fc;
+	struct ieee80211_rx_data rx;
+	struct ieee80211_sub_if_data *prev;
+	struct sta_info *sta, *tmp, *prev_sta;
+	int err = 0;
+
+	fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
+	memset(&rx, 0, sizeof(rx));
+	rx.skb = skb;
+	rx.local = local;
+
+	if (ieee80211_is_data(fc) || ieee80211_is_mgmt(fc))
+		local->dot11ReceivedFragmentCount++;
+
+	if (ieee80211_is_mgmt(fc)) {
+		/* drop frame if too short for header */
+		if (skb->len < ieee80211_hdrlen(fc))
+			err = -ENOBUFS;
+		else
+			err = skb_linearize(skb);
+	} else {
+		err = !pskb_may_pull(skb, ieee80211_hdrlen(fc));
+	}
+
+	if (err) {
+		dev_kfree_skb(skb);
+		return;
+	}
+
+	hdr = (struct ieee80211_hdr *)skb->data;
+	ieee80211_parse_qos(&rx);
+	ieee80211_verify_alignment(&rx);
+
+	if (unlikely(ieee80211_is_probe_resp(hdr->frame_control) ||
+		     ieee80211_is_beacon(hdr->frame_control)))
+		ieee80211_scan_rx(local, skb);
+
+	if (ieee80211_is_data(fc)) {
+		prev_sta = NULL;
+
+		for_each_sta_info(local, hdr->addr2, sta, tmp) {
+			if (!prev_sta) {
+				prev_sta = sta;
+				continue;
+			}
+
+			rx.sta = prev_sta;
+			rx.sdata = prev_sta->sdata;
+			ieee80211_prepare_and_rx_handle(&rx, skb, false);
+
+			prev_sta = sta;
+		}
+
+		if (prev_sta) {
+			rx.sta = prev_sta;
+			rx.sdata = prev_sta->sdata;
+
+			if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
+				return;
+			goto out;
+		}
+	}
+
+	prev = NULL;
+
+	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
+		if (!ieee80211_sdata_running(sdata))
+			continue;
+
+		if (sdata->vif.type == NL80211_IFTYPE_MONITOR ||
+		    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
+			continue;
+
+		/*
+		 * frame is destined for this interface, but if it's
+		 * not also for the previous one we handle that after
+		 * the loop to avoid copying the SKB once too much
+		 */
+
+		if (!prev) {
+			prev = sdata;
+			continue;
+		}
+
+		rx.sta = sta_info_get_bss(prev, hdr->addr2);
+		rx.sdata = prev;
+		ieee80211_prepare_and_rx_handle(&rx, skb, false);
+
+		prev = sdata;
+	}
+
+	if (prev) {
+		rx.sta = sta_info_get_bss(prev, hdr->addr2);
+		rx.sdata = prev;
+
+		if (ieee80211_prepare_and_rx_handle(&rx, skb, true))
+			return;
+	}
+
+ out:
+	dev_kfree_skb(skb);
+}
+
+/*
+ * This is the receive path handler. It is called by a low level driver when an
+ * 802.11 MPDU is received from the hardware.
+ */
+void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+	struct ieee80211_rate *rate = NULL;
+	struct ieee80211_supported_band *sband;
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
+
+	WARN_ON_ONCE(softirq_count() == 0);
+
+	if (WARN_ON(status->band >= IEEE80211_NUM_BANDS))
+		goto drop;
+
+	sband = local->hw.wiphy->bands[status->band];
+	if (WARN_ON(!sband))
+		goto drop;
+
+	/*
+	 * If we're suspending, it is possible although not too likely
+	 * that we'd be receiving frames after having already partially
+	 * quiesced the stack. We can't process such frames then since
+	 * that might, for example, cause stations to be added or other
+	 * driver callbacks be invoked.
+	 */
+	if (unlikely(local->quiescing || local->suspended))
+		goto drop;
+
+	/* We might be during a HW reconfig, prevent Rx for the same reason */
+	if (unlikely(local->in_reconfig))
+		goto drop;
+
+	/*
+	 * The same happens when we're not even started,
+	 * but that's worth a warning.
+	 */
+	if (WARN_ON(!local->started))
+		goto drop;
+
+	if (likely(!(status->flag & RX_FLAG_FAILED_PLCP_CRC))) {
+		/*
+		 * Validate the rate, unless a PLCP error means that
+		 * we probably can't have a valid rate here anyway.
+		 */
+
+		if (status->flag & RX_FLAG_HT) {
+			/*
+			 * rate_idx is MCS index, which can be [0-76]
+			 * as documented on:
+			 *
+			 * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
+			 *
+			 * Anything else would be some sort of driver or
+			 * hardware error. The driver should catch hardware
+			 * errors.
+			 */
+			if (WARN(status->rate_idx > 76,
+				 "Rate marked as an HT rate but passed "
+				 "status->rate_idx is not "
+				 "an MCS index [0-76]: %d (0x%02x)\n",
+				 status->rate_idx,
+				 status->rate_idx))
+				goto drop;
+		} else if (status->flag & RX_FLAG_VHT) {
+			if (WARN_ONCE(status->rate_idx > 9 ||
+				      !status->vht_nss ||
+				      status->vht_nss > 8,
+				      "Rate marked as a VHT rate but data is invalid: MCS: %d, NSS: %d\n",
+				      status->rate_idx, status->vht_nss))
+				goto drop;
+		} else {
+			if (WARN_ON(status->rate_idx >= sband->n_bitrates))
+				goto drop;
+			rate = &sband->bitrates[status->rate_idx];
+		}
+	}
+
+	status->rx_flags = 0;
+
+	/*
+	 * key references and virtual interfaces are protected using RCU
+	 * and this requires that we are in a read-side RCU section during
+	 * receive processing
+	 */
+	rcu_read_lock();
+
+	/*
+	 * Frames with failed FCS/PLCP checksum are not returned,
+	 * all other frames are returned without radiotap header
+	 * if it was previously present.
+	 * Also, frames with less than 16 bytes are dropped.
+	 */
+	skb = ieee80211_rx_monitor(local, skb, rate);
+	if (!skb) {
+		rcu_read_unlock();
+		return;
+	}
+
+	ieee80211_tpt_led_trig_rx(local,
+			((struct ieee80211_hdr *)skb->data)->frame_control,
+			skb->len);
+	__ieee80211_rx_handle_packet(hw, skb);
+
+	rcu_read_unlock();
+
+	return;
+ drop:
+	kfree_skb(skb);
+}
+EXPORT_SYMBOL(ieee80211_rx);
+
+/* This is a version of the rx handler that can be called from hard irq
+ * context. Post the skb on the queue and schedule the tasklet */
+void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb)
+{
+	struct ieee80211_local *local = hw_to_local(hw);
+
+	BUILD_BUG_ON(sizeof(struct ieee80211_rx_status) > sizeof(skb->cb));
+
+	skb->pkt_type = IEEE80211_RX_MSG;
+	skb_queue_tail(&local->skb_queue, skb);
+	tasklet_schedule(&local->tasklet);
+}
+EXPORT_SYMBOL(ieee80211_rx_irqsafe);
diff -Nur linux-3.18.12.orig/net/netfilter/core.c linux-3.18.12/net/netfilter/core.c
--- linux-3.18.12.orig/net/netfilter/core.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/net/netfilter/core.c	2015-04-26 13:32:22.471684003 -0500
@@ -21,11 +21,17 @@
 #include <linux/proc_fs.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
+#include <linux/locallock.h>
 #include <net/net_namespace.h>
 #include <net/sock.h>
 
 #include "nf_internals.h"
 
+#ifdef CONFIG_PREEMPT_RT_BASE
+DEFINE_LOCAL_IRQ_LOCK(xt_write_lock);
+EXPORT_PER_CPU_SYMBOL(xt_write_lock);
+#endif
+
 static DEFINE_MUTEX(afinfo_mutex);
 
 const struct nf_afinfo __rcu *nf_afinfo[NFPROTO_NUMPROTO] __read_mostly;
diff -Nur linux-3.18.12.orig/net/packet/af_packet.c linux-3.18.12/net/packet/af_packet.c
--- linux-3.18.12.orig/net/packet/af_packet.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/net/packet/af_packet.c	2015-04-26 13:32:22.471684003 -0500
@@ -63,6 +63,7 @@
 #include <linux/if_packet.h>
 #include <linux/wireless.h>
 #include <linux/kernel.h>
+#include <linux/delay.h>
 #include <linux/kmod.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
@@ -692,7 +693,7 @@
 	if (BLOCK_NUM_PKTS(pbd)) {
 		while (atomic_read(&pkc->blk_fill_in_prog)) {
 			/* Waiting for skb_copy_bits to finish... */
-			cpu_relax();
+			cpu_chill();
 		}
 	}
 
@@ -943,7 +944,7 @@
 		if (!(status & TP_STATUS_BLK_TMO)) {
 			while (atomic_read(&pkc->blk_fill_in_prog)) {
 				/* Waiting for skb_copy_bits to finish... */
-				cpu_relax();
+				cpu_chill();
 			}
 		}
 		prb_close_block(pkc, pbd, po, status);
diff -Nur linux-3.18.12.orig/net/rds/ib_rdma.c linux-3.18.12/net/rds/ib_rdma.c
--- linux-3.18.12.orig/net/rds/ib_rdma.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/net/rds/ib_rdma.c	2015-04-26 13:32:22.471684003 -0500
@@ -34,6 +34,7 @@
 #include <linux/slab.h>
 #include <linux/rculist.h>
 #include <linux/llist.h>
+#include <linux/delay.h>
 
 #include "rds.h"
 #include "ib.h"
@@ -286,7 +287,7 @@
 	for_each_online_cpu(cpu) {
 		flag = &per_cpu(clean_list_grace, cpu);
 		while (test_bit(CLEAN_LIST_BUSY_BIT, flag))
-			cpu_relax();
+			cpu_chill();
 	}
 }
 
diff -Nur linux-3.18.12.orig/net/sched/sch_generic.c linux-3.18.12/net/sched/sch_generic.c
--- linux-3.18.12.orig/net/sched/sch_generic.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/net/sched/sch_generic.c	2015-04-26 13:32:22.471684003 -0500
@@ -894,7 +894,7 @@
 	/* Wait for outstanding qdisc_run calls. */
 	list_for_each_entry(dev, head, close_list)
 		while (some_qdisc_is_busy(dev))
-			yield();
+			msleep(1);
 }
 
 void dev_deactivate(struct net_device *dev)
diff -Nur linux-3.18.12.orig/net/sunrpc/svc_xprt.c linux-3.18.12/net/sunrpc/svc_xprt.c
--- linux-3.18.12.orig/net/sunrpc/svc_xprt.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/net/sunrpc/svc_xprt.c	2015-04-26 13:32:22.475684003 -0500
@@ -357,7 +357,7 @@
 		return;
 	}
 
-	cpu = get_cpu();
+	cpu = get_cpu_light();
 	pool = svc_pool_for_cpu(xprt->xpt_server, cpu);
 	spin_lock_bh(&pool->sp_lock);
 
@@ -390,7 +390,7 @@
 	}
 
 	spin_unlock_bh(&pool->sp_lock);
-	put_cpu();
+	put_cpu_light();
 }
 
 /*
diff -Nur linux-3.18.12.orig/scripts/mkcompile_h linux-3.18.12/scripts/mkcompile_h
--- linux-3.18.12.orig/scripts/mkcompile_h	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/scripts/mkcompile_h	2015-04-26 13:32:22.475684003 -0500
@@ -4,7 +4,8 @@
 ARCH=$2
 SMP=$3
 PREEMPT=$4
-CC=$5
+RT=$5
+CC=$6
 
 vecho() { [ "${quiet}" = "silent_" ] || echo "$@" ; }
 
@@ -57,6 +58,7 @@
 CONFIG_FLAGS=""
 if [ -n "$SMP" ] ; then CONFIG_FLAGS="SMP"; fi
 if [ -n "$PREEMPT" ] ; then CONFIG_FLAGS="$CONFIG_FLAGS PREEMPT"; fi
+if [ -n "$RT" ] ; then CONFIG_FLAGS="$CONFIG_FLAGS RT"; fi
 UTS_VERSION="$UTS_VERSION $CONFIG_FLAGS $TIMESTAMP"
 
 # Truncate to maximum length
diff -Nur linux-3.18.12.orig/sound/core/pcm_native.c linux-3.18.12/sound/core/pcm_native.c
--- linux-3.18.12.orig/sound/core/pcm_native.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/sound/core/pcm_native.c	2015-04-26 13:32:22.475684003 -0500
@@ -104,7 +104,7 @@
 void snd_pcm_stream_lock_irq(struct snd_pcm_substream *substream)
 {
 	if (!substream->pcm->nonatomic)
-		local_irq_disable();
+		local_irq_disable_nort();
 	snd_pcm_stream_lock(substream);
 }
 EXPORT_SYMBOL_GPL(snd_pcm_stream_lock_irq);
@@ -113,7 +113,7 @@
 {
 	snd_pcm_stream_unlock(substream);
 	if (!substream->pcm->nonatomic)
-		local_irq_enable();
+		local_irq_enable_nort();
 }
 EXPORT_SYMBOL_GPL(snd_pcm_stream_unlock_irq);
 
@@ -121,7 +121,7 @@
 {
 	unsigned long flags = 0;
 	if (!substream->pcm->nonatomic)
-		local_irq_save(flags);
+		local_irq_save_nort(flags);
 	snd_pcm_stream_lock(substream);
 	return flags;
 }
@@ -132,7 +132,7 @@
 {
 	snd_pcm_stream_unlock(substream);
 	if (!substream->pcm->nonatomic)
-		local_irq_restore(flags);
+		local_irq_restore_nort(flags);
 }
 EXPORT_SYMBOL_GPL(snd_pcm_stream_unlock_irqrestore);
 
diff -Nur linux-3.18.12.orig/virt/kvm/async_pf.c linux-3.18.12/virt/kvm/async_pf.c
--- linux-3.18.12.orig/virt/kvm/async_pf.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/virt/kvm/async_pf.c	2015-04-26 13:32:22.475684003 -0500
@@ -94,8 +94,8 @@
 
 	trace_kvm_async_pf_completed(addr, gva);
 
-	if (waitqueue_active(&vcpu->wq))
-		wake_up_interruptible(&vcpu->wq);
+	if (swaitqueue_active(&vcpu->wq))
+		swait_wake_interruptible(&vcpu->wq);
 
 	mmput(mm);
 	kvm_put_kvm(vcpu->kvm);
diff -Nur linux-3.18.12.orig/virt/kvm/kvm_main.c linux-3.18.12/virt/kvm/kvm_main.c
--- linux-3.18.12.orig/virt/kvm/kvm_main.c	2015-04-20 14:48:02.000000000 -0500
+++ linux-3.18.12/virt/kvm/kvm_main.c	2015-04-26 13:32:22.475684003 -0500
@@ -221,7 +221,7 @@
 	vcpu->kvm = kvm;
 	vcpu->vcpu_id = id;
 	vcpu->pid = NULL;
-	init_waitqueue_head(&vcpu->wq);
+	init_swait_head(&vcpu->wq);
 	kvm_async_pf_vcpu_init(vcpu);
 
 	page = alloc_page(GFP_KERNEL | __GFP_ZERO);
@@ -1740,10 +1740,10 @@
  */
 void kvm_vcpu_block(struct kvm_vcpu *vcpu)
 {
-	DEFINE_WAIT(wait);
+	DEFINE_SWAITER(wait);
 
 	for (;;) {
-		prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
+		swait_prepare(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
 
 		if (kvm_arch_vcpu_runnable(vcpu)) {
 			kvm_make_request(KVM_REQ_UNHALT, vcpu);
@@ -1757,7 +1757,7 @@
 		schedule();
 	}
 
-	finish_wait(&vcpu->wq, &wait);
+	swait_finish(&vcpu->wq, &wait);
 }
 EXPORT_SYMBOL_GPL(kvm_vcpu_block);
 
@@ -1769,11 +1769,11 @@
 {
 	int me;
 	int cpu = vcpu->cpu;
-	wait_queue_head_t *wqp;
+	struct swait_head *wqp;
 
 	wqp = kvm_arch_vcpu_wq(vcpu);
-	if (waitqueue_active(wqp)) {
-		wake_up_interruptible(wqp);
+	if (swaitqueue_active(wqp)) {
+		swait_wake_interruptible(wqp);
 		++vcpu->stat.halt_wakeup;
 	}
 
@@ -1878,7 +1878,7 @@
 				continue;
 			if (vcpu == me)
 				continue;
-			if (waitqueue_active(&vcpu->wq) && !kvm_arch_vcpu_runnable(vcpu))
+			if (swaitqueue_active(&vcpu->wq) && !kvm_arch_vcpu_runnable(vcpu))
 				continue;
 			if (!kvm_vcpu_eligible_for_directed_yield(vcpu))
 				continue;
