Merge branch 'perf/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

20 files changed, 337 insertions, 233 deletions

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 1ceeb049c827..9c9b7545c810 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -2190,7 +2190,7 @@ int cpuset_cpus_allowed_fallback(struct task_struct *tsk)
         rcu_read_lock();
         cs = task_cs(tsk);
         if (cs)
-                cpumask_copy(&tsk->cpus_allowed, cs->cpus_allowed);
+                do_set_cpus_allowed(tsk, cs->cpus_allowed);
         rcu_read_unlock();
 
         /*
@@ -2217,7 +2217,7 @@ int cpuset_cpus_allowed_fallback(struct task_struct *tsk)
                  * Like above we can temporary set any mask and rely on
                  * set_cpus_allowed_ptr() as synchronization point.
                  */
-                cpumask_copy(&tsk->cpus_allowed, cpu_possible_mask);
+                do_set_cpus_allowed(tsk, cpu_possible_mask);
                 cpu = cpumask_any(cpu_active_mask);
         }
 
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 8a15944bf9d2..9efe7108ccaf 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5028,6 +5028,14 @@ static int __perf_event_overflow(struct perf_event *event, int nmi,
         else
                 perf_event_output(event, nmi, data, regs);
 
+        if (event->fasync && event->pending_kill) {
+                if (nmi) {
+                        event->pending_wakeup = 1;
+                        irq_work_queue(&event->pending);
+                } else
+                        perf_event_wakeup(event);
+        }
+
         return ret;
 }
 
diff --git a/kernel/fork.c b/kernel/fork.c
index ca406d916713..0276c30401a0 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -484,20 +484,6 @@ static void mm_init_aio(struct mm_struct *mm)
 #endif
 }
 
-int mm_init_cpumask(struct mm_struct *mm, struct mm_struct *oldmm)
-{
-#ifdef CONFIG_CPUMASK_OFFSTACK
-        if (!alloc_cpumask_var(&mm->cpu_vm_mask_var, GFP_KERNEL))
-                return -ENOMEM;
-
-        if (oldmm)
-                cpumask_copy(mm_cpumask(mm), mm_cpumask(oldmm));
-        else
-                memset(mm_cpumask(mm), 0, cpumask_size());
-#endif
-        return 0;
-}
-
 static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p)
 {
         atomic_set(&mm->mm_users, 1);
@@ -538,17 +524,8 @@ struct mm_struct * mm_alloc(void)
                 return NULL;
 
         memset(mm, 0, sizeof(*mm));
-        mm = mm_init(mm, current);
-        if (!mm)
-                return NULL;
-
-        if (mm_init_cpumask(mm, NULL)) {
-                mm_free_pgd(mm);
-                free_mm(mm);
-                return NULL;
-        }
-
-        return mm;
+        mm_init_cpumask(mm);
+        return mm_init(mm, current);
 }
 
 /*
@@ -559,7 +536,6 @@ struct mm_struct * mm_alloc(void)
 void __mmdrop(struct mm_struct *mm)
 {
         BUG_ON(mm == &init_mm);
-        free_cpumask_var(mm->cpu_vm_mask_var);
         mm_free_pgd(mm);
         destroy_context(mm);
         mmu_notifier_mm_destroy(mm);
@@ -753,6 +729,7 @@ struct mm_struct *dup_mm(struct task_struct *tsk)
                 goto fail_nomem;
 
         memcpy(mm, oldmm, sizeof(*mm));
+        mm_init_cpumask(mm);
 
         /* Initializing for Swap token stuff */
         mm->token_priority = 0;
@@ -765,9 +742,6 @@ struct mm_struct *dup_mm(struct task_struct *tsk)
         if (!mm_init(mm, tsk))
                 goto fail_nomem;
 
-        if (mm_init_cpumask(mm, oldmm))
-                goto fail_nocpumask;
-
         if (init_new_context(tsk, mm))
                 goto fail_nocontext;
 
@@ -794,9 +768,6 @@ fail_nomem:
         return NULL;
 
 fail_nocontext:
-        free_cpumask_var(mm->cpu_vm_mask_var);
-
-fail_nocpumask:
         /*
          * If init_new_context() failed, we cannot use mmput() to free the mm
          * because it calls destroy_context()
@@ -1591,6 +1562,13 @@ void __init proc_caches_init(void)
         fs_cachep = kmem_cache_create("fs_cache",
                         sizeof(struct fs_struct), 0,
                         SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_NOTRACK, NULL);
+        /*
+         * FIXME! The "sizeof(struct mm_struct)" currently includes the
+         * whole struct cpumask for the OFFSTACK case. We could change
+         * this to *only* allocate as much of it as required by the
+         * maximum number of CPU's we can ever have.  The cpumask_allocation
+         * is at the end of the structure, exactly for that reason.
+         */
         mm_cachep = kmem_cache_create("mm_struct",
                         sizeof(struct mm_struct), ARCH_MIN_MMSTRUCT_ALIGN,
                         SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_NOTRACK, NULL);
diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index 74d1c099fbd1..fa27e750dbc0 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -105,9 +105,12 @@ static int __jump_label_text_reserved(struct jump_entry *iter_start,
 }
 
 static void __jump_label_update(struct jump_label_key *key,
-                struct jump_entry *entry, int enable)
+                                struct jump_entry *entry,
+                                struct jump_entry *stop, int enable)
 {
-        for (; entry->key == (jump_label_t)(unsigned long)key; entry++) {
+        for (; (entry < stop) &&
+              (entry->key == (jump_label_t)(unsigned long)key);
+              entry++) {
                 /*
                  * entry->code set to 0 invalidates module init text sections
                  * kernel_text_address() verifies we are not in core kernel
@@ -181,7 +184,11 @@ static void __jump_label_mod_update(struct jump_label_key *key, int enable)
         struct jump_label_mod *mod = key->next;
 
         while (mod) {
-                __jump_label_update(key, mod->entries, enable);
+                struct module *m = mod->mod;
+
+                __jump_label_update(key, mod->entries,
+                                    m->jump_entries + m->num_jump_entries,
+                                    enable);
                 mod = mod->next;
         }
 }
@@ -245,7 +252,8 @@ static int jump_label_add_module(struct module *mod)
                 key->next = jlm;
 
                 if (jump_label_enabled(key))
-                        __jump_label_update(key, iter, JUMP_LABEL_ENABLE);
+                        __jump_label_update(key, iter, iter_stop,
+                                            JUMP_LABEL_ENABLE);
         }
 
         return 0;
@@ -371,7 +379,7 @@ static void jump_label_update(struct jump_label_key *key, int enable)
 
         /* if there are no users, entry can be NULL */
         if (entry)
-                __jump_label_update(key, entry, enable);
+                __jump_label_update(key, entry, __stop___jump_table, enable);
 
 #ifdef CONFIG_MODULES
         __jump_label_mod_update(key, enable);
diff --git a/kernel/kthread.c b/kernel/kthread.c
index 3b34d2732bce..4ba7cccb4994 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -202,8 +202,8 @@ void kthread_bind(struct task_struct *p, unsigned int cpu)
                 return;
         }
 
-        p->cpus_allowed = cpumask_of_cpu(cpu);
-        p->rt.nr_cpus_allowed = 1;
+        /* It's safe because the task is inactive. */
+        do_set_cpus_allowed(p, cpumask_of(cpu));
         p->flags |= PF_THREAD_BOUND;
 }
 EXPORT_SYMBOL(kthread_bind);
diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c
index fd8d1e035df9..6824ca7d4d0c 100644
--- a/kernel/pm_qos_params.c
+++ b/kernel/pm_qos_params.c
@@ -54,11 +54,17 @@ enum pm_qos_type {
         PM_QOS_MIN              /* return the smallest value */
 };
 
+/*
+ * Note: The lockless read path depends on the CPU accessing
+ * target_value atomically.  Atomic access is only guaranteed on all CPU
+ * types linux supports for 32 bit quantites
+ */
 struct pm_qos_object {
         struct plist_head requests;
         struct blocking_notifier_head *notifiers;
         struct miscdevice pm_qos_power_miscdev;
         char *name;
+        s32 target_value;       /* Do not change to 64 bit */
         s32 default_value;
         enum pm_qos_type type;
 };
@@ -71,7 +77,8 @@ static struct pm_qos_object cpu_dma_pm_qos = {
         .requests = PLIST_HEAD_INIT(cpu_dma_pm_qos.requests, pm_qos_lock),
         .notifiers = &cpu_dma_lat_notifier,
         .name = "cpu_dma_latency",
-        .default_value = 2000 * USEC_PER_SEC,
+        .target_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE,
+        .default_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE,
         .type = PM_QOS_MIN,
 };
 
@@ -80,7 +87,8 @@ static struct pm_qos_object network_lat_pm_qos = {
         .requests = PLIST_HEAD_INIT(network_lat_pm_qos.requests, pm_qos_lock),
         .notifiers = &network_lat_notifier,
         .name = "network_latency",
-        .default_value = 2000 * USEC_PER_SEC,
+        .target_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE,
+        .default_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE,
         .type = PM_QOS_MIN
 };
 
@@ -90,7 +98,8 @@ static struct pm_qos_object network_throughput_pm_qos = {
         .requests = PLIST_HEAD_INIT(network_throughput_pm_qos.requests, pm_qos_lock),
         .notifiers = &network_throughput_notifier,
         .name = "network_throughput",
-        .default_value = 0,
+        .target_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE,
+        .default_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE,
         .type = PM_QOS_MAX,
 };
 
@@ -136,6 +145,16 @@ static inline int pm_qos_get_value(struct pm_qos_object *o)
         }
 }
 
+static inline s32 pm_qos_read_value(struct pm_qos_object *o)
+{
+        return o->target_value;
+}
+
+static inline void pm_qos_set_value(struct pm_qos_object *o, s32 value)
+{
+        o->target_value = value;
+}
+
 static void update_target(struct pm_qos_object *o, struct plist_node *node,
                           int del, int value)
 {
@@ -160,6 +179,7 @@ static void update_target(struct pm_qos_object *o, struct plist_node *node,
                 plist_add(node, &o->requests);
         }
         curr_value = pm_qos_get_value(o);
+        pm_qos_set_value(o, curr_value);
         spin_unlock_irqrestore(&pm_qos_lock, flags);
 
         if (prev_value != curr_value)
@@ -194,18 +214,11 @@ static int find_pm_qos_object_by_minor(int minor)
  * pm_qos_request - returns current system wide qos expectation
  * @pm_qos_class: identification of which qos value is requested
  *
- * This function returns the current target value in an atomic manner.
+ * This function returns the current target value.
  */
 int pm_qos_request(int pm_qos_class)
 {
-        unsigned long flags;
-        int value;
-
-        spin_lock_irqsave(&pm_qos_lock, flags);
-        value = pm_qos_get_value(pm_qos_array[pm_qos_class]);
-        spin_unlock_irqrestore(&pm_qos_lock, flags);
-
-        return value;
+        return pm_qos_read_value(pm_qos_array[pm_qos_class]);
 }
 EXPORT_SYMBOL_GPL(pm_qos_request);
 
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index f07d2f03181a..89419ff92e99 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -36,7 +36,7 @@
 #include <linux/interrupt.h>
 #include <linux/sched.h>
 #include <linux/nmi.h>
-#include <asm/atomic.h>
+#include <linux/atomic.h>
 #include <linux/bitops.h>
 #include <linux/module.h>
 #include <linux/completion.h>
@@ -95,7 +95,6 @@ static DEFINE_PER_CPU(struct task_struct *, rcu_cpu_kthread_task);
 DEFINE_PER_CPU(unsigned int, rcu_cpu_kthread_status);
 DEFINE_PER_CPU(int, rcu_cpu_kthread_cpu);
 DEFINE_PER_CPU(unsigned int, rcu_cpu_kthread_loops);
-static DEFINE_PER_CPU(wait_queue_head_t, rcu_cpu_wq);
 DEFINE_PER_CPU(char, rcu_cpu_has_work);
 static char rcu_kthreads_spawnable;
 
@@ -163,7 +162,7 @@ EXPORT_SYMBOL_GPL(rcu_note_context_switch);
 #ifdef CONFIG_NO_HZ
 DEFINE_PER_CPU(struct rcu_dynticks, rcu_dynticks) = {
         .dynticks_nesting = 1,
-        .dynticks = 1,
+        .dynticks = ATOMIC_INIT(1),
 };
 #endif /* #ifdef CONFIG_NO_HZ */
 
@@ -322,13 +321,25 @@ void rcu_enter_nohz(void)
         unsigned long flags;
         struct rcu_dynticks *rdtp;
 
-        smp_mb(); /* CPUs seeing ++ must see prior RCU read-side crit sects */
         local_irq_save(flags);
         rdtp = &__get_cpu_var(rcu_dynticks);
-        rdtp->dynticks++;
-        rdtp->dynticks_nesting--;
-        WARN_ON_ONCE(rdtp->dynticks & 0x1);
+        if (--rdtp->dynticks_nesting) {
+                local_irq_restore(flags);
+                return;
+        }
+        /* CPUs seeing atomic_inc() must see prior RCU read-side crit sects */
+        smp_mb__before_atomic_inc();  /* See above. */
+        atomic_inc(&rdtp->dynticks);
+        smp_mb__after_atomic_inc();  /* Force ordering with next sojourn. */
+        WARN_ON_ONCE(atomic_read(&rdtp->dynticks) & 0x1);
         local_irq_restore(flags);
+
+        /* If the interrupt queued a callback, get out of dyntick mode. */
+        if (in_irq() &&
+            (__get_cpu_var(rcu_sched_data).nxtlist ||
+             __get_cpu_var(rcu_bh_data).nxtlist ||
+             rcu_preempt_needs_cpu(smp_processor_id())))
+                set_need_resched();
 }
 
 /*
@@ -344,11 +355,16 @@ void rcu_exit_nohz(void)
 
         local_irq_save(flags);
         rdtp = &__get_cpu_var(rcu_dynticks);
-        rdtp->dynticks++;
-        rdtp->dynticks_nesting++;
-        WARN_ON_ONCE(!(rdtp->dynticks & 0x1));
+        if (rdtp->dynticks_nesting++) {
+                local_irq_restore(flags);
+                return;
+        }
+        smp_mb__before_atomic_inc();  /* Force ordering w/previous sojourn. */
+        atomic_inc(&rdtp->dynticks);
+        /* CPUs seeing atomic_inc() must see later RCU read-side crit sects */
+        smp_mb__after_atomic_inc();  /* See above. */
+        WARN_ON_ONCE(!(atomic_read(&rdtp->dynticks) & 0x1));
         local_irq_restore(flags);
-        smp_mb(); /* CPUs seeing ++ must see later RCU read-side crit sects */
 }
 
 /**
@@ -362,11 +378,15 @@ void rcu_nmi_enter(void)
 {
         struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks);
 
-        if (rdtp->dynticks & 0x1)
+        if (rdtp->dynticks_nmi_nesting == 0 &&
+            (atomic_read(&rdtp->dynticks) & 0x1))
                 return;
-        rdtp->dynticks_nmi++;
-        WARN_ON_ONCE(!(rdtp->dynticks_nmi & 0x1));
-        smp_mb(); /* CPUs seeing ++ must see later RCU read-side crit sects */
+        rdtp->dynticks_nmi_nesting++;
+        smp_mb__before_atomic_inc();  /* Force delay from prior write. */
+        atomic_inc(&rdtp->dynticks);
+        /* CPUs seeing atomic_inc() must see later RCU read-side crit sects */
+        smp_mb__after_atomic_inc();  /* See above. */
+        WARN_ON_ONCE(!(atomic_read(&rdtp->dynticks) & 0x1));
 }
 
 /**
@@ -380,11 +400,14 @@ void rcu_nmi_exit(void)
 {
         struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks);
 
-        if (rdtp->dynticks & 0x1)
+        if (rdtp->dynticks_nmi_nesting == 0 ||
+            --rdtp->dynticks_nmi_nesting != 0)
                 return;
-        smp_mb(); /* CPUs seeing ++ must see prior RCU read-side crit sects */
-        rdtp->dynticks_nmi++;
-        WARN_ON_ONCE(rdtp->dynticks_nmi & 0x1);
+        /* CPUs seeing atomic_inc() must see prior RCU read-side crit sects */
+        smp_mb__before_atomic_inc();  /* See above. */
+        atomic_inc(&rdtp->dynticks);
+        smp_mb__after_atomic_inc();  /* Force delay to next write. */
+        WARN_ON_ONCE(atomic_read(&rdtp->dynticks) & 0x1);
 }
 
 /**
@@ -395,13 +418,7 @@ void rcu_nmi_exit(void)
  */
 void rcu_irq_enter(void)
 {
-        struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks);
-
-        if (rdtp->dynticks_nesting++)
-                return;
-        rdtp->dynticks++;
-        WARN_ON_ONCE(!(rdtp->dynticks & 0x1));
-        smp_mb(); /* CPUs seeing ++ must see later RCU read-side crit sects */
+        rcu_exit_nohz();
 }
 
 /**
@@ -413,18 +430,7 @@ void rcu_irq_enter(void)
  */
 void rcu_irq_exit(void)
 {
-        struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks);
-
-        if (--rdtp->dynticks_nesting)
-                return;
-        smp_mb(); /* CPUs seeing ++ must see prior RCU read-side crit sects */
-        rdtp->dynticks++;
-        WARN_ON_ONCE(rdtp->dynticks & 0x1);
-
-        /* If the interrupt queued a callback, get out of dyntick mode. */
-        if (__this_cpu_read(rcu_sched_data.nxtlist) ||
-            __this_cpu_read(rcu_bh_data.nxtlist))
-                set_need_resched();
+        rcu_enter_nohz();
 }
 
 #ifdef CONFIG_SMP
@@ -436,19 +442,8 @@ void rcu_irq_exit(void)
  */
 static int dyntick_save_progress_counter(struct rcu_data *rdp)
 {
-        int ret;
-        int snap;
-        int snap_nmi;
-
-        snap = rdp->dynticks->dynticks;
-        snap_nmi = rdp->dynticks->dynticks_nmi;
-        smp_mb();       /* Order sampling of snap with end of grace period. */
-        rdp->dynticks_snap = snap;
-        rdp->dynticks_nmi_snap = snap_nmi;
-        ret = ((snap & 0x1) == 0) && ((snap_nmi & 0x1) == 0);
-        if (ret)
-                rdp->dynticks_fqs++;
-        return ret;
+        rdp->dynticks_snap = atomic_add_return(0, &rdp->dynticks->dynticks);
+        return 0;
 }
 
 /*
@@ -459,16 +454,11 @@ static int dyntick_save_progress_counter(struct rcu_data *rdp)
  */
 static int rcu_implicit_dynticks_qs(struct rcu_data *rdp)
 {
-        long curr;
-        long curr_nmi;
-        long snap;
-        long snap_nmi;
+        unsigned long curr;
+        unsigned long snap;
 
-        curr = rdp->dynticks->dynticks;
-        snap = rdp->dynticks_snap;
-        curr_nmi = rdp->dynticks->dynticks_nmi;
-        snap_nmi = rdp->dynticks_nmi_snap;
-        smp_mb(); /* force ordering with cpu entering/leaving dynticks. */
+        curr = (unsigned long)atomic_add_return(0, &rdp->dynticks->dynticks);
+        snap = (unsigned long)rdp->dynticks_snap;
 
         /*
          * If the CPU passed through or entered a dynticks idle phase with
@@ -478,8 +468,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp)
          * read-side critical section that started before the beginning
          * of the current RCU grace period.
          */
-        if ((curr != snap || (curr & 0x1) == 0) &&
-            (curr_nmi != snap_nmi || (curr_nmi & 0x1) == 0)) {
+        if ((curr & 0x1) == 0 || ULONG_CMP_GE(curr, snap + 2)) {
                 rdp->dynticks_fqs++;
                 return 1;
         }
@@ -908,6 +897,12 @@ static void rcu_report_qs_rsp(struct rcu_state *rsp, unsigned long flags)
         unsigned long gp_duration;
 
         WARN_ON_ONCE(!rcu_gp_in_progress(rsp));
+
+        /*
+         * Ensure that all grace-period and pre-grace-period activity
+         * is seen before the assignment to rsp->completed.
+         */
+        smp_mb(); /* See above block comment. */
         gp_duration = jiffies - rsp->gp_start;
         if (gp_duration > rsp->gp_max)
                 rsp->gp_max = gp_duration;
@@ -1455,25 +1450,11 @@ __rcu_process_callbacks(struct rcu_state *rsp, struct rcu_data *rdp)
  */
 static void rcu_process_callbacks(void)
 {
-        /*
-         * Memory references from any prior RCU read-side critical sections
-         * executed by the interrupted code must be seen before any RCU
-         * grace-period manipulations below.
-         */
-        smp_mb(); /* See above block comment. */
-
         __rcu_process_callbacks(&rcu_sched_state,
                                 &__get_cpu_var(rcu_sched_data));
         __rcu_process_callbacks(&rcu_bh_state, &__get_cpu_var(rcu_bh_data));
         rcu_preempt_process_callbacks();
 
-        /*
-         * Memory references from any later RCU read-side critical sections
-         * executed by the interrupted code must be seen after any RCU
-         * grace-period manipulations above.
-         */
-        smp_mb(); /* See above block comment. */
-
         /* If we are last CPU on way to dyntick-idle mode, accelerate it. */
         rcu_needs_cpu_flush();
 }
@@ -1494,7 +1475,7 @@ static void invoke_rcu_cpu_kthread(void)
                 local_irq_restore(flags);
                 return;
         }
-        wake_up(&__get_cpu_var(rcu_cpu_wq));
+        wake_up_process(__this_cpu_read(rcu_cpu_kthread_task));
         local_irq_restore(flags);
 }
 
@@ -1544,13 +1525,10 @@ static void rcu_cpu_kthread_setrt(int cpu, int to_rt)
  */
 static void rcu_cpu_kthread_timer(unsigned long arg)
 {
-        unsigned long flags;
         struct rcu_data *rdp = per_cpu_ptr(rcu_state->rda, arg);
         struct rcu_node *rnp = rdp->mynode;
 
-        raw_spin_lock_irqsave(&rnp->lock, flags);
-        rnp->wakemask |= rdp->grpmask;
-        raw_spin_unlock_irqrestore(&rnp->lock, flags);
+        atomic_or(rdp->grpmask, &rnp->wakemask);
         invoke_rcu_node_kthread(rnp);
 }
 
@@ -1617,14 +1595,12 @@ static int rcu_cpu_kthread(void *arg)
         unsigned long flags;
         int spincnt = 0;
         unsigned int *statusp = &per_cpu(rcu_cpu_kthread_status, cpu);
-        wait_queue_head_t *wqp = &per_cpu(rcu_cpu_wq, cpu);
         char work;
         char *workp = &per_cpu(rcu_cpu_has_work, cpu);
 
         for (;;) {
                 *statusp = RCU_KTHREAD_WAITING;
-                wait_event_interruptible(*wqp,
-                                         *workp != 0 || kthread_should_stop());
+                rcu_wait(*workp != 0 || kthread_should_stop());
                 local_bh_disable();
                 if (rcu_cpu_kthread_should_stop(cpu)) {
                         local_bh_enable();
@@ -1675,7 +1651,6 @@ static int __cpuinit rcu_spawn_one_cpu_kthread(int cpu)
         per_cpu(rcu_cpu_kthread_cpu, cpu) = cpu;
         WARN_ON_ONCE(per_cpu(rcu_cpu_kthread_task, cpu) != NULL);
         per_cpu(rcu_cpu_kthread_task, cpu) = t;
-        wake_up_process(t);
         sp.sched_priority = RCU_KTHREAD_PRIO;
         sched_setscheduler_nocheck(t, SCHED_FIFO, &sp);
         return 0;
@@ -1698,11 +1673,10 @@ static int rcu_node_kthread(void *arg)
 
         for (;;) {
                 rnp->node_kthread_status = RCU_KTHREAD_WAITING;
-                wait_event_interruptible(rnp->node_wq, rnp->wakemask != 0);
+                rcu_wait(atomic_read(&rnp->wakemask) != 0);
                 rnp->node_kthread_status = RCU_KTHREAD_RUNNING;
                 raw_spin_lock_irqsave(&rnp->lock, flags);
-                mask = rnp->wakemask;
-                rnp->wakemask = 0;
+                mask = atomic_xchg(&rnp->wakemask, 0);
                 rcu_initiate_boost(rnp, flags); /* releases rnp->lock. */
                 for (cpu = rnp->grplo; cpu <= rnp->grphi; cpu++, mask >>= 1) {
                         if ((mask & 0x1) == 0)
@@ -1783,13 +1757,14 @@ static int __cpuinit rcu_spawn_one_node_kthread(struct rcu_state *rsp,
                 raw_spin_lock_irqsave(&rnp->lock, flags);
                 rnp->node_kthread_task = t;
                 raw_spin_unlock_irqrestore(&rnp->lock, flags);
-                wake_up_process(t);
                 sp.sched_priority = 99;
                 sched_setscheduler_nocheck(t, SCHED_FIFO, &sp);
         }
         return rcu_spawn_one_boost_kthread(rsp, rnp, rnp_index);
 }
 
+static void rcu_wake_one_boost_kthread(struct rcu_node *rnp);
+
 /*
  * Spawn all kthreads -- called as soon as the scheduler is running.
  */
@@ -1797,24 +1772,31 @@ static int __init rcu_spawn_kthreads(void)
 {
         int cpu;
         struct rcu_node *rnp;
+        struct task_struct *t;
 
         rcu_kthreads_spawnable = 1;
         for_each_possible_cpu(cpu) {
-                init_waitqueue_head(&per_cpu(rcu_cpu_wq, cpu));
                 per_cpu(rcu_cpu_has_work, cpu) = 0;
-                if (cpu_online(cpu))
+                if (cpu_online(cpu)) {
                         (void)rcu_spawn_one_cpu_kthread(cpu);
+                        t = per_cpu(rcu_cpu_kthread_task, cpu);
+                        if (t)
+                                wake_up_process(t);
+                }
         }
         rnp = rcu_get_root(rcu_state);
-        init_waitqueue_head(&rnp->node_wq);
-        rcu_init_boost_waitqueue(rnp);
         (void)rcu_spawn_one_node_kthread(rcu_state, rnp);
-        if (NUM_RCU_NODES > 1)
+        if (rnp->node_kthread_task)
+                wake_up_process(rnp->node_kthread_task);
+        if (NUM_RCU_NODES > 1) {
                 rcu_for_each_leaf_node(rcu_state, rnp) {
-                        init_waitqueue_head(&rnp->node_wq);
-                        rcu_init_boost_waitqueue(rnp);
                         (void)rcu_spawn_one_node_kthread(rcu_state, rnp);
+                        t = rnp->node_kthread_task;
+                        if (t)
+                                wake_up_process(t);
+                        rcu_wake_one_boost_kthread(rnp);
                 }
+        }
         return 0;
 }
 early_initcall(rcu_spawn_kthreads);
@@ -2218,14 +2200,14 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptible)
         raw_spin_unlock_irqrestore(&rsp->onofflock, flags);
 }
 
-static void __cpuinit rcu_online_cpu(int cpu)
+static void __cpuinit rcu_prepare_cpu(int cpu)
 {
         rcu_init_percpu_data(cpu, &rcu_sched_state, 0);
         rcu_init_percpu_data(cpu, &rcu_bh_state, 0);
         rcu_preempt_init_percpu_data(cpu);
 }
 
-static void __cpuinit rcu_online_kthreads(int cpu)
+static void __cpuinit rcu_prepare_kthreads(int cpu)
 {
         struct rcu_data *rdp = per_cpu_ptr(rcu_state->rda, cpu);
         struct rcu_node *rnp = rdp->mynode;
@@ -2239,6 +2221,31 @@ static void __cpuinit rcu_online_kthreads(int cpu)
 }
 
 /*
+ * kthread_create() creates threads in TASK_UNINTERRUPTIBLE state,
+ * but the RCU threads are woken on demand, and if demand is low this
+ * could be a while triggering the hung task watchdog.
+ *
+ * In order to avoid this, poke all tasks once the CPU is fully
+ * up and running.
+ */
+static void __cpuinit rcu_online_kthreads(int cpu)
+{
+        struct rcu_data *rdp = per_cpu_ptr(rcu_state->rda, cpu);
+        struct rcu_node *rnp = rdp->mynode;
+        struct task_struct *t;
+
+        t = per_cpu(rcu_cpu_kthread_task, cpu);
+        if (t)
+                wake_up_process(t);
+
+        t = rnp->node_kthread_task;
+        if (t)
+                wake_up_process(t);
+
+        rcu_wake_one_boost_kthread(rnp);
+}
+
+/*
  * Handle CPU online/offline notification events.
  */
 static int __cpuinit rcu_cpu_notify(struct notifier_block *self,
@@ -2251,10 +2258,11 @@ static int __cpuinit rcu_cpu_notify(struct notifier_block *self,
         switch (action) {
         case CPU_UP_PREPARE:
         case CPU_UP_PREPARE_FROZEN:
-                rcu_online_cpu(cpu);
-                rcu_online_kthreads(cpu);
+                rcu_prepare_cpu(cpu);
+                rcu_prepare_kthreads(cpu);
                 break;
         case CPU_ONLINE:
+                rcu_online_kthreads(cpu);
         case CPU_DOWN_FAILED:
                 rcu_node_kthread_setaffinity(rnp, -1);
                 rcu_cpu_kthread_setrt(cpu, 1);
diff --git a/kernel/rcutree.h b/kernel/rcutree.h
index 257664815d5d..7b9a08b4aaea 100644
--- a/kernel/rcutree.h
+++ b/kernel/rcutree.h
@@ -84,11 +84,9 @@
  * Dynticks per-CPU state.
  */
 struct rcu_dynticks {
-        int dynticks_nesting;   /* Track nesting level, sort of. */
-        int dynticks;           /* Even value for dynticks-idle, else odd. */
-        int dynticks_nmi;       /* Even value for either dynticks-idle or */
-                                /*  not in nmi handler, else odd.  So this */
-                                /*  remains even for nmi from irq handler. */
+        int dynticks_nesting;   /* Track irq/process nesting level. */
+        int dynticks_nmi_nesting; /* Track NMI nesting level. */
+        atomic_t dynticks;      /* Even value for dynticks-idle, else odd. */
 };
 
 /* RCU's kthread states for tracing. */
@@ -121,7 +119,9 @@ struct rcu_node {
                                 /*  elements that need to drain to allow the */
                                 /*  current expedited grace period to */
                                 /*  complete (only for TREE_PREEMPT_RCU). */
-        unsigned long wakemask; /* CPUs whose kthread needs to be awakened. */
+        atomic_t wakemask;      /* CPUs whose kthread needs to be awakened. */
+                                /*  Since this has meaning only for leaf */
+                                /*  rcu_node structures, 32 bits suffices. */
         unsigned long qsmaskinit;
                                 /* Per-GP initial value for qsmask & expmask. */
         unsigned long grpmask;  /* Mask to apply to parent qsmask. */
@@ -159,9 +159,6 @@ struct rcu_node {
         struct task_struct *boost_kthread_task;
                                 /* kthread that takes care of priority */
                                 /*  boosting for this rcu_node structure. */
-        wait_queue_head_t boost_wq;
-                                /* Wait queue on which to park the boost */
-                                /*  kthread. */
         unsigned int boost_kthread_status;
                                 /* State of boost_kthread_task for tracing. */
         unsigned long n_tasks_boosted;
@@ -188,9 +185,6 @@ struct rcu_node {
                                 /* kthread that takes care of this rcu_node */
                                 /*  structure, for example, awakening the */
                                 /*  per-CPU kthreads as needed. */
-        wait_queue_head_t node_wq;
-                                /* Wait queue on which to park the per-node */
-                                /*  kthread. */
         unsigned int node_kthread_status;
                                 /* State of node_kthread_task for tracing. */
 } ____cacheline_internodealigned_in_smp;
@@ -284,7 +278,6 @@ struct rcu_data {
         /* 3) dynticks interface. */
         struct rcu_dynticks *dynticks;  /* Shared per-CPU dynticks state. */
         int dynticks_snap;              /* Per-GP tracking for dynticks. */
-        int dynticks_nmi_snap;          /* Per-GP tracking for dynticks_nmi. */
 #endif /* #ifdef CONFIG_NO_HZ */
 
         /* 4) reasons this CPU needed to be kicked by force_quiescent_state */
@@ -337,6 +330,16 @@ struct rcu_data {
                                                 /*  scheduling clock irq */
                                                 /*  before ratting on them. */
 
+#define rcu_wait(cond)                                                  \
+do {                                                                    \
+        for (;;) {                                                      \
+                set_current_state(TASK_INTERRUPTIBLE);                  \
+                if (cond)                                               \
+                        break;                                          \
+                schedule();                                             \
+        }                                                               \
+        __set_current_state(TASK_RUNNING);                              \
+} while (0)
 
 /*
  * RCU global state, including node hierarchy.  This hierarchy is
@@ -446,7 +449,6 @@ static void __cpuinit rcu_preempt_init_percpu_data(int cpu);
 static void rcu_preempt_send_cbs_to_online(void);
 static void __init __rcu_init_preempt(void);
 static void rcu_needs_cpu_flush(void);
-static void __init rcu_init_boost_waitqueue(struct rcu_node *rnp);
 static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags);
 static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp,
                                           cpumask_var_t cm);
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 3f6559a5f5cd..c8bff3099a89 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -1196,8 +1196,7 @@ static int rcu_boost_kthread(void *arg)
 
         for (;;) {
                 rnp->boost_kthread_status = RCU_KTHREAD_WAITING;
-                wait_event_interruptible(rnp->boost_wq, rnp->boost_tasks ||
-                                                        rnp->exp_tasks);
+                rcu_wait(rnp->boost_tasks || rnp->exp_tasks);
                 rnp->boost_kthread_status = RCU_KTHREAD_RUNNING;
                 more2boost = rcu_boost(rnp);
                 if (more2boost)
@@ -1275,14 +1274,6 @@ static void rcu_preempt_boost_start_gp(struct rcu_node *rnp)
 }
 
 /*
- * Initialize the RCU-boost waitqueue.
- */
-static void __init rcu_init_boost_waitqueue(struct rcu_node *rnp)
-{
-        init_waitqueue_head(&rnp->boost_wq);
-}
-
-/*
  * Create an RCU-boost kthread for the specified node if one does not
  * already exist.  We only create this kthread for preemptible RCU.
  * Returns zero if all is well, a negated errno otherwise.
@@ -1306,12 +1297,17 @@ static int __cpuinit rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
         raw_spin_lock_irqsave(&rnp->lock, flags);
         rnp->boost_kthread_task = t;
         raw_spin_unlock_irqrestore(&rnp->lock, flags);
-        wake_up_process(t);
         sp.sched_priority = RCU_KTHREAD_PRIO;
         sched_setscheduler_nocheck(t, SCHED_FIFO, &sp);
         return 0;
 }
 
+static void __cpuinit rcu_wake_one_boost_kthread(struct rcu_node *rnp)
+{
+        if (rnp->boost_kthread_task)
+                wake_up_process(rnp->boost_kthread_task);
+}
+
 #else /* #ifdef CONFIG_RCU_BOOST */
 
 static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags)
@@ -1328,10 +1324,6 @@ static void rcu_preempt_boost_start_gp(struct rcu_node *rnp)
 {
 }
 
-static void __init rcu_init_boost_waitqueue(struct rcu_node *rnp)
-{
-}
-
 static int __cpuinit rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
                                                  struct rcu_node *rnp,
                                                  int rnp_index)
@@ -1339,6 +1331,10 @@ static int __cpuinit rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
         return 0;
 }
 
+static void __cpuinit rcu_wake_one_boost_kthread(struct rcu_node *rnp)
+{
+}
+
 #endif /* #else #ifdef CONFIG_RCU_BOOST */
 
 #ifndef CONFIG_SMP
@@ -1520,7 +1516,6 @@ int rcu_needs_cpu(int cpu)
 {
         int c = 0;
         int snap;
-        int snap_nmi;
         int thatcpu;
 
         /* Check for being in the holdoff period. */
@@ -1531,10 +1526,10 @@ int rcu_needs_cpu(int cpu)
         for_each_online_cpu(thatcpu) {
                 if (thatcpu == cpu)
                         continue;
-                snap = per_cpu(rcu_dynticks, thatcpu).dynticks;
-                snap_nmi = per_cpu(rcu_dynticks, thatcpu).dynticks_nmi;
+                snap = atomic_add_return(0, &per_cpu(rcu_dynticks,
+                                                     thatcpu).dynticks);
                 smp_mb(); /* Order sampling of snap with end of grace period. */
-                if (((snap & 0x1) != 0) || ((snap_nmi & 0x1) != 0)) {
+                if ((snap & 0x1) != 0) {
                         per_cpu(rcu_dyntick_drain, cpu) = 0;
                         per_cpu(rcu_dyntick_holdoff, cpu) = jiffies - 1;
                         return rcu_needs_cpu_quick_check(cpu);
diff --git a/kernel/rcutree_trace.c b/kernel/rcutree_trace.c
index aa0fd72b4bc7..9678cc3650f5 100644
--- a/kernel/rcutree_trace.c
+++ b/kernel/rcutree_trace.c
@@ -69,10 +69,10 @@ static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)
                    rdp->passed_quiesc, rdp->passed_quiesc_completed,
                    rdp->qs_pending);
 #ifdef CONFIG_NO_HZ
-        seq_printf(m, " dt=%d/%d dn=%d df=%lu",
-                   rdp->dynticks->dynticks,
+        seq_printf(m, " dt=%d/%d/%d df=%lu",
+                   atomic_read(&rdp->dynticks->dynticks),
                    rdp->dynticks->dynticks_nesting,
-                   rdp->dynticks->dynticks_nmi,
+                   rdp->dynticks->dynticks_nmi_nesting,
                    rdp->dynticks_fqs);
 #endif /* #ifdef CONFIG_NO_HZ */
         seq_printf(m, " of=%lu ri=%lu", rdp->offline_fqs, rdp->resched_ipi);
@@ -141,9 +141,9 @@ static void print_one_rcu_data_csv(struct seq_file *m, struct rcu_data *rdp)
                    rdp->qs_pending);
 #ifdef CONFIG_NO_HZ
         seq_printf(m, ",%d,%d,%d,%lu",
-                   rdp->dynticks->dynticks,
+                   atomic_read(&rdp->dynticks->dynticks),
                    rdp->dynticks->dynticks_nesting,
-                   rdp->dynticks->dynticks_nmi,
+                   rdp->dynticks->dynticks_nmi_nesting,
                    rdp->dynticks_fqs);
 #endif /* #ifdef CONFIG_NO_HZ */
         seq_printf(m, ",%lu,%lu", rdp->offline_fqs, rdp->resched_ipi);
@@ -167,7 +167,7 @@ static int show_rcudata_csv(struct seq_file *m, void *unused)
 {
         seq_puts(m, "\"CPU\",\"Online?\",\"c\",\"g\",\"pq\",\"pqc\",\"pq\",");
 #ifdef CONFIG_NO_HZ
-        seq_puts(m, "\"dt\",\"dt nesting\",\"dn\",\"df\",");
+        seq_puts(m, "\"dt\",\"dt nesting\",\"dt NMI nesting\",\"df\",");
 #endif /* #ifdef CONFIG_NO_HZ */
         seq_puts(m, "\"of\",\"ri\",\"ql\",\"b\",\"ci\",\"co\",\"ca\"\n");
 #ifdef CONFIG_TREE_PREEMPT_RCU
diff --git a/kernel/sched.c b/kernel/sched.c
index 5e43e9dc65d1..cbb3a0eee58e 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2573,7 +2573,26 @@ static void ttwu_queue_remote(struct task_struct *p, int cpu)
         if (!next)
                 smp_send_reschedule(cpu);
 }
-#endif
+
+#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
+static int ttwu_activate_remote(struct task_struct *p, int wake_flags)
+{
+        struct rq *rq;
+        int ret = 0;
+
+        rq = __task_rq_lock(p);
+        if (p->on_cpu) {
+                ttwu_activate(rq, p, ENQUEUE_WAKEUP);
+                ttwu_do_wakeup(rq, p, wake_flags);
+                ret = 1;
+        }
+        __task_rq_unlock(rq);
+
+        return ret;
+
+}
+#endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */
+#endif /* CONFIG_SMP */
 
 static void ttwu_queue(struct task_struct *p, int cpu)
 {
@@ -2631,17 +2650,17 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
         while (p->on_cpu) {
 #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
                 /*
-                 * If called from interrupt context we could have landed in the
-                 * middle of schedule(), in this case we should take care not
-                 * to spin on ->on_cpu if p is current, since that would
-                 * deadlock.
+                 * In case the architecture enables interrupts in
+                 * context_switch(), we cannot busy wait, since that
+                 * would lead to deadlocks when an interrupt hits and
+                 * tries to wake up @prev. So bail and do a complete
+                 * remote wakeup.
                  */
-                if (p == current) {
-                        ttwu_queue(p, cpu);
+                if (ttwu_activate_remote(p, wake_flags))
                         goto stat;
-                }
-#endif
+#else
                 cpu_relax();
+#endif
         }
         /*
          * Pairs with the smp_wmb() in finish_lock_switch().
@@ -5841,7 +5860,7 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu)
         idle->state = TASK_RUNNING;
         idle->se.exec_start = sched_clock();
 
-        cpumask_copy(&idle->cpus_allowed, cpumask_of(cpu));
+        do_set_cpus_allowed(idle, cpumask_of(cpu));
         /*
          * We're having a chicken and egg problem, even though we are
          * holding rq->lock, the cpu isn't yet set to this cpu so the
@@ -5929,6 +5948,16 @@ static inline void sched_init_granularity(void)
 }
 
 #ifdef CONFIG_SMP
+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);
+        else {
+                cpumask_copy(&p->cpus_allowed, new_mask);
+                p->rt.nr_cpus_allowed = cpumask_weight(new_mask);
+        }
+}
+
 /*
  * This is how migration works:
  *
@@ -5974,12 +6003,7 @@ int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
                 goto out;
         }
 
-        if (p->sched_class->set_cpus_allowed)
-                p->sched_class->set_cpus_allowed(p, new_mask);
-        else {
-                cpumask_copy(&p->cpus_allowed, new_mask);
-                p->rt.nr_cpus_allowed = cpumask_weight(new_mask);
-        }
+        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))
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index e32a9b70ee9c..433491c2dc8f 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -1076,8 +1076,6 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
         se->on_rq = 0;
         update_cfs_load(cfs_rq, 0);
         account_entity_dequeue(cfs_rq, se);
-        update_min_vruntime(cfs_rq);
-        update_cfs_shares(cfs_rq);
 
         /*
          * Normalize the entity after updating the min_vruntime because the
@@ -1086,6 +1084,9 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
          */
         if (!(flags & DEQUEUE_SLEEP))
                 se->vruntime -= cfs_rq->min_vruntime;
+
+        update_min_vruntime(cfs_rq);
+        update_cfs_shares(cfs_rq);
 }
 
 /*
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 64b2a37c07d0..88725c939e0b 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -1263,6 +1263,7 @@ static int find_lowest_rq(struct task_struct *task)
         if (!cpumask_test_cpu(this_cpu, lowest_mask))
                 this_cpu = -1; /* Skip this_cpu opt if not among lowest */
 
+        rcu_read_lock();
         for_each_domain(cpu, sd) {
                 if (sd->flags & SD_WAKE_AFFINE) {
                         int best_cpu;
@@ -1272,15 +1273,20 @@ static int find_lowest_rq(struct task_struct *task)
                          * remote processor.
                          */
                         if (this_cpu != -1 &&
-                            cpumask_test_cpu(this_cpu, sched_domain_span(sd)))
+                            cpumask_test_cpu(this_cpu, sched_domain_span(sd))) {
+                                rcu_read_unlock();
                                 return this_cpu;
+                        }
 
                         best_cpu = cpumask_first_and(lowest_mask,
                                                      sched_domain_span(sd));
-                        if (best_cpu < nr_cpu_ids)
+                        if (best_cpu < nr_cpu_ids) {
+                                rcu_read_unlock();
                                 return best_cpu;
+                        }
                 }
         }
+        rcu_read_unlock();
 
         /*
          * And finally, if there were no matches within the domains
diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h
index 48ddf431db0e..331e01bcd026 100644
--- a/kernel/sched_stats.h
+++ b/kernel/sched_stats.h
@@ -37,7 +37,7 @@ static int show_schedstat(struct seq_file *seq, void *v)
 
 #ifdef CONFIG_SMP
                 /* domain-specific stats */
-                preempt_disable();
+                rcu_read_lock();
                 for_each_domain(cpu, sd) {
                         enum cpu_idle_type itype;
 
@@ -64,7 +64,7 @@ static int show_schedstat(struct seq_file *seq, void *v)
                             sd->ttwu_wake_remote, sd->ttwu_move_affine,
                             sd->ttwu_move_balance);
                 }
-                preempt_enable();
+                rcu_read_unlock();
 #endif
         }
         kfree(mask_str);
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index d017c2c82c44..1ee417fcbfa5 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -109,12 +109,18 @@ ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip);
 static void ftrace_global_list_func(unsigned long ip,
                                     unsigned long parent_ip)
 {
-        struct ftrace_ops *op = rcu_dereference_raw(ftrace_global_list); /*see above*/
+        struct ftrace_ops *op;
+
+        if (unlikely(trace_recursion_test(TRACE_GLOBAL_BIT)))
+                return;
 
+        trace_recursion_set(TRACE_GLOBAL_BIT);
+        op = rcu_dereference_raw(ftrace_global_list); /*see above*/
         while (op != &ftrace_list_end) {
                 op->func(ip, parent_ip);
                 op = rcu_dereference_raw(op->next); /*see above*/
         };
+        trace_recursion_clear(TRACE_GLOBAL_BIT);
 }
 
 static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip)
@@ -1638,12 +1644,12 @@ static void ftrace_startup_enable(int command)
         ftrace_run_update_code(command);
 }
 
-static void ftrace_startup(struct ftrace_ops *ops, int command)
+static int ftrace_startup(struct ftrace_ops *ops, int command)
 {
         bool hash_enable = true;
 
         if (unlikely(ftrace_disabled))
-                return;
+                return -ENODEV;
 
         ftrace_start_up++;
         command |= FTRACE_ENABLE_CALLS;
@@ -1662,6 +1668,8 @@ static void ftrace_startup(struct ftrace_ops *ops, int command)
                 ftrace_hash_rec_enable(ops, 1);
 
         ftrace_startup_enable(command);
+
+        return 0;
 }
 
 static void ftrace_shutdown(struct ftrace_ops *ops, int command)
@@ -2501,7 +2509,7 @@ static void __enable_ftrace_function_probe(void)
 
         ret = __register_ftrace_function(&trace_probe_ops);
         if (!ret)
-                ftrace_startup(&trace_probe_ops, 0);
+                ret = ftrace_startup(&trace_probe_ops, 0);
 
         ftrace_probe_registered = 1;
 }
@@ -3466,7 +3474,11 @@ device_initcall(ftrace_nodyn_init);
 static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
 static inline void ftrace_startup_enable(int command) { }
 /* Keep as macros so we do not need to define the commands */
-# define ftrace_startup(ops, command)   do { } while (0)
+# define ftrace_startup(ops, command)                   \
+        ({                                              \
+                (ops)->flags |= FTRACE_OPS_FL_ENABLED;  \
+                0;                                      \
+        })
 # define ftrace_shutdown(ops, command)  do { } while (0)
 # define ftrace_startup_sysctl()        do { } while (0)
 # define ftrace_shutdown_sysctl()       do { } while (0)
@@ -3484,6 +3496,10 @@ ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip)
 {
         struct ftrace_ops *op;
 
+        if (unlikely(trace_recursion_test(TRACE_INTERNAL_BIT)))
+                return;
+
+        trace_recursion_set(TRACE_INTERNAL_BIT);
         /*
          * Some of the ops may be dynamically allocated,
          * they must be freed after a synchronize_sched().
@@ -3496,6 +3512,7 @@ ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip)
                 op = rcu_dereference_raw(op->next);
         };
         preempt_enable_notrace();
+        trace_recursion_clear(TRACE_INTERNAL_BIT);
 }
 
 static void clear_ftrace_swapper(void)
@@ -3799,7 +3816,7 @@ int register_ftrace_function(struct ftrace_ops *ops)
 
         ret = __register_ftrace_function(ops);
         if (!ret)
-                ftrace_startup(ops, 0);
+                ret = ftrace_startup(ops, 0);
 
 
  out_unlock:
@@ -4045,7 +4062,7 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc,
         ftrace_graph_return = retfunc;
         ftrace_graph_entry = entryfunc;
 
-        ftrace_startup(&global_ops, FTRACE_START_FUNC_RET);
+        ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET);
 
 out:
         mutex_unlock(&ftrace_lock);
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 0ef7b4b2a1f7..b0c7aa407943 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -2216,7 +2216,7 @@ static noinline void trace_recursive_fail(void)
 
         printk_once(KERN_WARNING "Tracing recursion: depth[%ld]:"
                     "HC[%lu]:SC[%lu]:NMI[%lu]\n",
-                    current->trace_recursion,
+                    trace_recursion_buffer(),
                     hardirq_count() >> HARDIRQ_SHIFT,
                     softirq_count() >> SOFTIRQ_SHIFT,
                     in_nmi());
@@ -2226,9 +2226,9 @@ static noinline void trace_recursive_fail(void)
 
 static inline int trace_recursive_lock(void)
 {
-        current->trace_recursion++;
+        trace_recursion_inc();
 
-        if (likely(current->trace_recursion < TRACE_RECURSIVE_DEPTH))
+        if (likely(trace_recursion_buffer() < TRACE_RECURSIVE_DEPTH))
                 return 0;
 
         trace_recursive_fail();
@@ -2238,9 +2238,9 @@ static inline int trace_recursive_lock(void)
 
 static inline void trace_recursive_unlock(void)
 {
-        WARN_ON_ONCE(!current->trace_recursion);
+        WARN_ON_ONCE(!trace_recursion_buffer());
 
-        current->trace_recursion--;
+        trace_recursion_dec();
 }
 
 #else
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 6b69c4bd306f..229f8591f61d 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -784,4 +784,19 @@ extern const char *__stop___trace_bprintk_fmt[];
         FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
 #include "trace_entries.h"
 
+/* Only current can touch trace_recursion */
+#define trace_recursion_inc() do { (current)->trace_recursion++; } while (0)
+#define trace_recursion_dec() do { (current)->trace_recursion--; } while (0)
+
+/* Ring buffer has the 10 LSB bits to count */
+#define trace_recursion_buffer() ((current)->trace_recursion & 0x3ff)
+
+/* for function tracing recursion */
+#define TRACE_INTERNAL_BIT              (1<<11)
+#define TRACE_GLOBAL_BIT                (1<<12)
+
+#define trace_recursion_set(bit)        do { (current)->trace_recursion |= (bit); } while (0)
+#define trace_recursion_clear(bit)      do { (current)->trace_recursion &= ~(bit); } while (0)
+#define trace_recursion_test(bit)       ((current)->trace_recursion & (bit))
+
 #endif /* _LINUX_KERNEL_TRACE_H */
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 2fe110341359..686ec399f2a8 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1657,7 +1657,12 @@ static struct ftrace_ops trace_ops __initdata  =
 
 static __init void event_trace_self_test_with_function(void)
 {
-        register_ftrace_function(&trace_ops);
+        int ret;
+        ret = register_ftrace_function(&trace_ops);
+        if (WARN_ON(ret < 0)) {
+                pr_info("Failed to enable function tracer for event tests\n");
+                return;
+        }
         pr_info("Running tests again, along with the function tracer\n");
         event_trace_self_tests();
         unregister_ftrace_function(&trace_ops);
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index cf535ccedc86..e37de492a9e1 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -353,6 +353,33 @@ ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
 }
 EXPORT_SYMBOL(ftrace_print_symbols_seq);
 
+#if BITS_PER_LONG == 32
+const char *
+ftrace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val,
+                         const struct trace_print_flags_u64 *symbol_array)
+{
+        int i;
+        const char *ret = p->buffer + p->len;
+
+        for (i = 0;  symbol_array[i].name; i++) {
+
+                if (val != symbol_array[i].mask)
+                        continue;
+
+                trace_seq_puts(p, symbol_array[i].name);
+                break;
+        }
+
+        if (!p->len)
+                trace_seq_printf(p, "0x%llx", val);
+
+        trace_seq_putc(p, 0);
+
+        return ret;
+}
+EXPORT_SYMBOL(ftrace_print_symbols_seq_u64);
+#endif
+
 const char *
 ftrace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len)
 {
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 7daa4b072e9f..3d0c56ad4792 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -415,15 +415,13 @@ static void watchdog_nmi_disable(int cpu) { return; }
 #endif /* CONFIG_HARDLOCKUP_DETECTOR */
 
 /* prepare/enable/disable routines */
-static int watchdog_prepare_cpu(int cpu)
+static void watchdog_prepare_cpu(int cpu)
 {
         struct hrtimer *hrtimer = &per_cpu(watchdog_hrtimer, cpu);
 
         WARN_ON(per_cpu(softlockup_watchdog, cpu));
         hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
         hrtimer->function = watchdog_timer_fn;
-
-        return 0;
 }
 
 static int watchdog_enable(int cpu)
@@ -542,17 +540,16 @@ static int __cpuinit
 cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
 {
         int hotcpu = (unsigned long)hcpu;
-        int err = 0;
 
         switch (action) {
         case CPU_UP_PREPARE:
         case CPU_UP_PREPARE_FROZEN:
-                err = watchdog_prepare_cpu(hotcpu);
+                watchdog_prepare_cpu(hotcpu);
                 break;
         case CPU_ONLINE:
         case CPU_ONLINE_FROZEN:
                 if (watchdog_enabled)
-                        err = watchdog_enable(hotcpu);
+                        watchdog_enable(hotcpu);
                 break;
 #ifdef CONFIG_HOTPLUG_CPU
         case CPU_UP_CANCELED: