Merge commit 'v3.3-rc4'

19 files changed, 270 insertions, 85 deletions

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index caaea6e944f8..af1de0f34eae 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1863,11 +1863,12 @@ void __audit_syscall_entry(int arch, int major,
 
 /**
  * audit_syscall_exit - deallocate audit context after a system call
- * @pt_regs: syscall registers
+ * @success: success value of the syscall
+ * @return_code: return value of the syscall
  *
  * Tear down after system call.  If the audit context has been marked as
  * auditable (either because of the AUDIT_RECORD_CONTEXT state from
- * filtering, or because some other part of the kernel write an audit
+ * filtering, or because some other part of the kernel wrote an audit
  * message), then write out the syscall information.  In call cases,
  * free the names stored from getname().
  */
diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c
index 057e24b665cf..6581a040f399 100644
--- a/kernel/events/callchain.c
+++ b/kernel/events/callchain.c
@@ -115,8 +115,6 @@ int get_callchain_buffers(void)
         }
 
         err = alloc_callchain_buffers();
-        if (err)
-                release_callchain_buffers();
 exit:
         mutex_unlock(&callchain_mutex);
 
diff --git a/kernel/events/core.c b/kernel/events/core.c
index a8f4ac001a00..1b5c081d8b9f 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -815,7 +815,7 @@ static void update_event_times(struct perf_event *event)
          * here.
          */
         if (is_cgroup_event(event))
-                run_end = perf_event_time(event);
+                run_end = perf_cgroup_event_time(event);
         else if (ctx->is_active)
                 run_end = ctx->time;
         else
@@ -2300,7 +2300,10 @@ do {					\
         return div64_u64(dividend, divisor);
 }
 
-static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count)
+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;
@@ -2319,22 +2322,40 @@ static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count)
         hwc->sample_period = sample_period;
 
         if (local64_read(&hwc->period_left) > 8*sample_period) {
-                event->pmu->stop(event, PERF_EF_UPDATE);
+                if (disable)
+                        event->pmu->stop(event, PERF_EF_UPDATE);
+
                 local64_set(&hwc->period_left, 0);
-                event->pmu->start(event, PERF_EF_RELOAD);
+
+                if (disable)
+                        event->pmu->start(event, PERF_EF_RELOAD);
         }
 }
 
-static void perf_ctx_adjust_freq(struct perf_event_context *ctx, u64 period)
+/*
+ * 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 interrupts, now;
+        u64 now, period = TICK_NSEC;
         s64 delta;
 
-        if (!ctx->nr_freq)
+        /*
+         * 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;
@@ -2344,13 +2365,8 @@ static void perf_ctx_adjust_freq(struct perf_event_context *ctx, u64 period)
 
                 hwc = &event->hw;
 
-                interrupts = hwc->interrupts;
-                hwc->interrupts = 0;
-
-                /*
-                 * unthrottle events on the tick
-                 */
-                if (interrupts == MAX_INTERRUPTS) {
+                if (needs_unthr && hwc->interrupts == MAX_INTERRUPTS) {
+                        hwc->interrupts = 0;
                         perf_log_throttle(event, 1);
                         event->pmu->start(event, 0);
                 }
@@ -2358,14 +2374,30 @@ static void perf_ctx_adjust_freq(struct perf_event_context *ctx, u64 period)
                 if (!event->attr.freq || !event->attr.sample_freq)
                         continue;
 
-                event->pmu->read(event);
+                /*
+                 * 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);
+                        perf_adjust_period(event, period, delta, false);
+
+                event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0);
         }
+
+        perf_pmu_enable(ctx->pmu);
+        raw_spin_unlock(&ctx->lock);
 }
 
 /*
@@ -2388,16 +2420,13 @@ static void rotate_ctx(struct perf_event_context *ctx)
  */
 static void perf_rotate_context(struct perf_cpu_context *cpuctx)
 {
-        u64 interval = (u64)cpuctx->jiffies_interval * TICK_NSEC;
         struct perf_event_context *ctx = NULL;
-        int rotate = 0, remove = 1, freq = 0;
+        int rotate = 0, remove = 1;
 
         if (cpuctx->ctx.nr_events) {
                 remove = 0;
                 if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active)
                         rotate = 1;
-                if (cpuctx->ctx.nr_freq)
-                        freq = 1;
         }
 
         ctx = cpuctx->task_ctx;
@@ -2405,37 +2434,26 @@ static void perf_rotate_context(struct perf_cpu_context *cpuctx)
                 remove = 0;
                 if (ctx->nr_events != ctx->nr_active)
                         rotate = 1;
-                if (ctx->nr_freq)
-                        freq = 1;
         }
 
-        if (!rotate && !freq)
+        if (!rotate)
                 goto done;
 
         perf_ctx_lock(cpuctx, cpuctx->task_ctx);
         perf_pmu_disable(cpuctx->ctx.pmu);
 
-        if (freq) {
-                perf_ctx_adjust_freq(&cpuctx->ctx, interval);
-                if (ctx)
-                        perf_ctx_adjust_freq(ctx, interval);
-        }
-
-        if (rotate) {
-                cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
-                if (ctx)
-                        ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE);
+        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);
+        rotate_ctx(&cpuctx->ctx);
+        if (ctx)
+                rotate_ctx(ctx);
 
-                perf_event_sched_in(cpuctx, ctx, current);
-        }
+        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);
@@ -2445,10 +2463,22 @@ void perf_event_task_tick(void)
 {
         struct list_head *head = &__get_cpu_var(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);
+
                 if (cpuctx->jiffies_interval == 1 ||
                                 !(jiffies % cpuctx->jiffies_interval))
                         perf_rotate_context(cpuctx);
@@ -4509,6 +4539,7 @@ static int __perf_event_overflow(struct perf_event *event,
 {
         int events = atomic_read(&event->event_limit);
         struct hw_perf_event *hwc = &event->hw;
+        u64 seq;
         int ret = 0;
 
         /*
@@ -4518,14 +4549,20 @@ static int __perf_event_overflow(struct perf_event *event,
         if (unlikely(!is_sampling_event(event)))
                 return 0;
 
-        if (unlikely(hwc->interrupts >= max_samples_per_tick)) {
-                if (throttle) {
+        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);
                         ret = 1;
                 }
-        } else
-                hwc->interrupts++;
+        }
 
         if (event->attr.freq) {
                 u64 now = perf_clock();
@@ -4534,7 +4571,7 @@ static int __perf_event_overflow(struct perf_event *event,
                 hwc->freq_time_stamp = now;
 
                 if (delta > 0 && delta < 2*TICK_NSEC)
-                        perf_adjust_period(event, delta, hwc->last_period);
+                        perf_adjust_period(event, delta, hwc->last_period, true);
         }
 
         /*
diff --git a/kernel/exit.c b/kernel/exit.c
index 294b1709170d..4b4042f9bc6a 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1038,6 +1038,22 @@ void do_exit(long code)
         if (tsk->nr_dirtied)
                 __this_cpu_add(dirty_throttle_leaks, tsk->nr_dirtied);
         exit_rcu();
+
+        /*
+         * The setting of TASK_RUNNING by try_to_wake_up() may be delayed
+         * when the following two conditions become true.
+         *   - There is race condition of mmap_sem (It is acquired by
+         *     exit_mm()), and
+         *   - SMI occurs before setting TASK_RUNINNG.
+         *     (or hypervisor of virtual machine switches to other guest)
+         *  As a result, we may become TASK_RUNNING after becoming TASK_DEAD
+         *
+         * To avoid it, we have to wait for releasing tsk->pi_lock which
+         * is held by try_to_wake_up()
+         */
+        smp_mb();
+        raw_spin_unlock_wait(&tsk->pi_lock);
+
         /* causes final put_task_struct in finish_task_switch(). */
         tsk->state = TASK_DEAD;
         tsk->flags |= PF_NOFREEZE;      /* tell freezer to ignore us */
diff --git a/kernel/fork.c b/kernel/fork.c
index 051f090d40c1..b77fd559c78e 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -647,6 +647,26 @@ struct mm_struct *get_task_mm(struct task_struct *task)
 }
 EXPORT_SYMBOL_GPL(get_task_mm);
 
+struct mm_struct *mm_access(struct task_struct *task, unsigned int mode)
+{
+        struct mm_struct *mm;
+        int err;
+
+        err =  mutex_lock_killable(&task->signal->cred_guard_mutex);
+        if (err)
+                return ERR_PTR(err);
+
+        mm = get_task_mm(task);
+        if (mm && mm != current->mm &&
+                        !ptrace_may_access(task, mode)) {
+                mmput(mm);
+                mm = ERR_PTR(-EACCES);
+        }
+        mutex_unlock(&task->signal->cred_guard_mutex);
+
+        return mm;
+}
+
 /* Please note the differences between mmput and mm_release.
  * mmput is called whenever we stop holding onto a mm_struct,
  * error success whatever.
@@ -890,7 +910,7 @@ static int copy_io(unsigned long clone_flags, struct task_struct *tsk)
                         return -ENOMEM;
 
                 new_ioc->ioprio = ioc->ioprio;
-                put_io_context(new_ioc, NULL);
+                put_io_context(new_ioc);
         }
 #endif
         return 0;
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 95dd7212e610..9788c0ec6f43 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1077,6 +1077,7 @@ void __kprobes kprobe_flush_task(struct task_struct *tk)
                 /* Early boot.  kretprobe_table_locks not yet initialized. */
                 return;
 
+        INIT_HLIST_HEAD(&empty_rp);
         hash = hash_ptr(tk, KPROBE_HASH_BITS);
         head = &kretprobe_inst_table[hash];
         kretprobe_table_lock(hash, &flags);
@@ -1085,7 +1086,6 @@ void __kprobes kprobe_flush_task(struct task_struct *tk)
                         recycle_rp_inst(ri, &empty_rp);
         }
         kretprobe_table_unlock(hash, &flags);
-        INIT_HLIST_HEAD(&empty_rp);
         hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
                 hlist_del(&ri->hlist);
                 kfree(ri);
@@ -1673,8 +1673,12 @@ static int __kprobes pre_handler_kretprobe(struct kprobe *p,
                 ri->rp = rp;
                 ri->task = current;
 
-                if (rp->entry_handler && rp->entry_handler(ri, regs))
+                if (rp->entry_handler && rp->entry_handler(ri, regs)) {
+                        raw_spin_lock_irqsave(&rp->lock, flags);
+                        hlist_add_head(&ri->hlist, &rp->free_instances);
+                        raw_spin_unlock_irqrestore(&rp->lock, flags);
                         return 0;
+                }
 
                 arch_prepare_kretprobe(ri, regs);
 
diff --git a/kernel/params.c b/kernel/params.c
index 32ee04308285..4bc965d8a1fe 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -97,7 +97,8 @@ static int parse_one(char *param,
         for (i = 0; i < num_params; i++) {
                 if (parameq(param, params[i].name)) {
                         /* No one handled NULL, so do it here. */
-                        if (!val && params[i].ops->set != param_set_bool)
+                        if (!val && params[i].ops->set != param_set_bool
+                            && params[i].ops->set != param_set_bint)
                                 return -EINVAL;
                         pr_debug("They are equal!  Calling %p\n",
                                params[i].ops->set);
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 0c4defe6d3b8..21724eee5206 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -231,8 +231,28 @@ extern int pm_test_level;
 #ifdef CONFIG_SUSPEND_FREEZER
 static inline int suspend_freeze_processes(void)
 {
-        int error = freeze_processes();
-        return error ? : freeze_kernel_threads();
+        int error;
+
+        error = freeze_processes();
+
+        /*
+         * freeze_processes() automatically thaws every task if freezing
+         * fails. So we need not do anything extra upon error.
+         */
+        if (error)
+                goto Finish;
+
+        error = freeze_kernel_threads();
+
+        /*
+         * freeze_kernel_threads() thaws only kernel threads upon freezing
+         * failure. So we have to thaw the userspace tasks ourselves.
+         */
+        if (error)
+                thaw_processes();
+
+ Finish:
+        return error;
 }
 
 static inline void suspend_thaw_processes(void)
diff --git a/kernel/power/process.c b/kernel/power/process.c
index 77274c9ba2f1..7e426459e60a 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -143,7 +143,10 @@ int freeze_processes(void)
 /**
  * freeze_kernel_threads - Make freezable kernel threads go to the refrigerator.
  *
- * On success, returns 0.  On failure, -errno and system is fully thawed.
+ * On success, returns 0.  On failure, -errno and only the kernel threads are
+ * thawed, so as to give a chance to the caller to do additional cleanups
+ * (if any) before thawing the userspace tasks. So, it is the responsibility
+ * of the caller to thaw the userspace tasks, when the time is right.
  */
 int freeze_kernel_threads(void)
 {
@@ -159,7 +162,7 @@ int freeze_kernel_threads(void)
         BUG_ON(in_atomic());
 
         if (error)
-                thaw_processes();
+                thaw_kernel_threads();
         return error;
 }
 
@@ -188,3 +191,22 @@ void thaw_processes(void)
         printk("done.\n");
 }
 
+void thaw_kernel_threads(void)
+{
+        struct task_struct *g, *p;
+
+        pm_nosig_freezing = false;
+        printk("Restarting kernel threads ... ");
+
+        thaw_workqueues();
+
+        read_lock(&tasklist_lock);
+        do_each_thread(g, p) {
+                if (p->flags & (PF_KTHREAD | PF_WQ_WORKER))
+                        __thaw_task(p);
+        } while_each_thread(g, p);
+        read_unlock(&tasklist_lock);
+
+        schedule();
+        printk("done.\n");
+}
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 1cf88900ec4f..6a768e537001 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -812,7 +812,8 @@ unsigned int snapshot_additional_pages(struct zone *zone)
         unsigned int res;
 
         res = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK);
-        res += DIV_ROUND_UP(res * sizeof(struct bm_block), PAGE_SIZE);
+        res += DIV_ROUND_UP(res * sizeof(struct bm_block),
+                            LINKED_PAGE_DATA_SIZE);
         return 2 * res;
 }
 
diff --git a/kernel/power/user.c b/kernel/power/user.c
index 6b1ab7a88522..3e100075b13c 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -249,13 +249,15 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
                 }
                 pm_restore_gfp_mask();
                 error = hibernation_snapshot(data->platform_support);
-                if (!error) {
+                if (error) {
+                        thaw_kernel_threads();
+                } else {
                         error = put_user(in_suspend, (int __user *)arg);
                         if (!error && !freezer_test_done)
                                 data->ready = 1;
                         if (freezer_test_done) {
                                 freezer_test_done = false;
-                                thaw_processes();
+                                thaw_kernel_threads();
                         }
                 }
                 break;
@@ -274,6 +276,15 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
                 swsusp_free();
                 memset(&data->handle, 0, sizeof(struct snapshot_handle));
                 data->ready = 0;
+                /*
+                 * It is necessary to thaw kernel threads here, because
+                 * SNAPSHOT_CREATE_IMAGE may be invoked directly after
+                 * SNAPSHOT_FREE.  In that case, if kernel threads were not
+                 * thawed, the preallocation of memory carried out by
+                 * hibernation_snapshot() might run into problems (i.e. it
+                 * might fail or even deadlock).
+                 */
+                thaw_kernel_threads();
                 break;
 
         case SNAPSHOT_PREF_IMAGE_SIZE:
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index 88f17b8a3b1d..a58ac285fc69 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -56,8 +56,8 @@ static int nreaders = -1;	/* # reader threads, defaults to 2*ncpus */
 static int nfakewriters = 4;    /* # fake writer threads */
 static int stat_interval;       /* Interval between stats, in seconds. */
                                 /*  Defaults to "only at end of test". */
-static int verbose;             /* Print more debug info. */
-static int test_no_idle_hz;     /* Test RCU's support for tickless idle CPUs. */
+static bool verbose;            /* Print more debug info. */
+static bool test_no_idle_hz;    /* Test RCU's support for tickless idle CPUs. */
 static int shuffle_interval = 3; /* Interval between shuffles (in sec)*/
 static int stutter = 5;         /* Start/stop testing interval (in sec) */
 static int irqreader = 1;       /* RCU readers from irq (timers). */
@@ -1399,7 +1399,7 @@ rcu_torture_shutdown(void *arg)
  * Execute random CPU-hotplug operations at the interval specified
  * by the onoff_interval.
  */
-static int
+static int __cpuinit
 rcu_torture_onoff(void *arg)
 {
         int cpu;
@@ -1447,7 +1447,7 @@ rcu_torture_onoff(void *arg)
         return 0;
 }
 
-static int
+static int __cpuinit
 rcu_torture_onoff_init(void)
 {
         if (onoff_interval <= 0)
diff --git a/kernel/relay.c b/kernel/relay.c
index 4335e1d7ee2d..ab56a1764d4d 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -164,10 +164,14 @@ depopulate:
  */
 static struct rchan_buf *relay_create_buf(struct rchan *chan)
 {
-        struct rchan_buf *buf = kzalloc(sizeof(struct rchan_buf), GFP_KERNEL);
-        if (!buf)
+        struct rchan_buf *buf;
+
+        if (chan->n_subbufs > UINT_MAX / sizeof(size_t *))
                 return NULL;
 
+        buf = kzalloc(sizeof(struct rchan_buf), GFP_KERNEL);
+        if (!buf)
+                return NULL;
         buf->padding = kmalloc(chan->n_subbufs * sizeof(size_t *), GFP_KERNEL);
         if (!buf->padding)
                 goto free_buf;
@@ -574,6 +578,8 @@ struct rchan *relay_open(const char *base_filename,
 
         if (!(subbuf_size && n_subbufs))
                 return NULL;
+        if (subbuf_size > UINT_MAX / n_subbufs)
+                return NULL;
 
         chan = kzalloc(sizeof(struct rchan), GFP_KERNEL);
         if (!chan)
diff --git a/kernel/res_counter.c b/kernel/res_counter.c
index 6d269cce7aa1..d508363858b3 100644
--- a/kernel/res_counter.c
+++ b/kernel/res_counter.c
@@ -66,6 +66,31 @@ done:
         return ret;
 }
 
+int res_counter_charge_nofail(struct res_counter *counter, unsigned long val,
+                              struct res_counter **limit_fail_at)
+{
+        int ret, r;
+        unsigned long flags;
+        struct res_counter *c;
+
+        r = ret = 0;
+        *limit_fail_at = NULL;
+        local_irq_save(flags);
+        for (c = counter; c != NULL; c = c->parent) {
+                spin_lock(&c->lock);
+                r = res_counter_charge_locked(c, val);
+                if (r)
+                        c->usage += val;
+                spin_unlock(&c->lock);
+                if (r < 0 && ret == 0) {
+                        *limit_fail_at = c;
+                        ret = r;
+                }
+        }
+        local_irq_restore(flags);
+
+        return ret;
+}
 void res_counter_uncharge_locked(struct res_counter *counter, unsigned long val)
 {
         if (WARN_ON(counter->usage < val))
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index df00cb09263e..5255c9d2e053 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -74,6 +74,7 @@
 
 #include <asm/tlb.h>
 #include <asm/irq_regs.h>
+#include <asm/mutex.h>
 #ifdef CONFIG_PARAVIRT
 #include <asm/paravirt.h>
 #endif
@@ -723,9 +724,6 @@ static void dequeue_task(struct rq *rq, struct task_struct *p, int flags)
         p->sched_class->dequeue_task(rq, p, flags);
 }
 
-/*
- * activate_task - move a task to the runqueue.
- */
 void activate_task(struct rq *rq, struct task_struct *p, int flags)
 {
         if (task_contributes_to_load(p))
@@ -734,9 +732,6 @@ void activate_task(struct rq *rq, struct task_struct *p, int flags)
         enqueue_task(rq, p, flags);
 }
 
-/*
- * deactivate_task - remove a task from the runqueue.
- */
 void deactivate_task(struct rq *rq, struct task_struct *p, int flags)
 {
         if (task_contributes_to_load(p))
@@ -4134,7 +4129,7 @@ recheck:
         on_rq = p->on_rq;
         running = task_current(rq, p);
         if (on_rq)
-                deactivate_task(rq, p, 0);
+                dequeue_task(rq, p, 0);
         if (running)
                 p->sched_class->put_prev_task(rq, p);
 
@@ -4147,7 +4142,7 @@ recheck:
         if (running)
                 p->sched_class->set_curr_task(rq);
         if (on_rq)
-                activate_task(rq, p, 0);
+                enqueue_task(rq, p, 0);
 
         check_class_changed(rq, p, prev_class, oldprio);
         task_rq_unlock(rq, p, &flags);
@@ -4998,9 +4993,9 @@ static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu)
          * placed properly.
          */
         if (p->on_rq) {
-                deactivate_task(rq_src, p, 0);
+                dequeue_task(rq_src, p, 0);
                 set_task_cpu(p, dest_cpu);
-                activate_task(rq_dest, p, 0);
+                enqueue_task(rq_dest, p, 0);
                 check_preempt_curr(rq_dest, p, 0);
         }
 done:
@@ -7032,10 +7027,10 @@ static void normalize_task(struct rq *rq, struct task_struct *p)
 
         on_rq = p->on_rq;
         if (on_rq)
-                deactivate_task(rq, p, 0);
+                dequeue_task(rq, p, 0);
         __setscheduler(rq, p, SCHED_NORMAL, 0);
         if (on_rq) {
-                activate_task(rq, p, 0);
+                enqueue_task(rq, p, 0);
                 resched_task(rq->curr);
         }
 
diff --git a/kernel/sched/cpupri.c b/kernel/sched/cpupri.c
index b0d798eaf130..d72586fdf660 100644
--- a/kernel/sched/cpupri.c
+++ b/kernel/sched/cpupri.c
@@ -129,7 +129,7 @@ int cpupri_find(struct cpupri *cp, struct task_struct *p,
  * cpupri_set - update the cpu priority setting
  * @cp: The cpupri context
  * @cpu: The target cpu
- * @pri: The priority (INVALID-RT99) to assign to this CPU
+ * @newpri: The priority (INVALID-RT99) to assign to this CPU
  *
  * Note: Assumes cpu_rq(cpu)->lock is locked
  *
@@ -200,7 +200,6 @@ void cpupri_set(struct cpupri *cp, int cpu, int newpri)
 /**
  * cpupri_init - initialize the cpupri structure
  * @cp: The cpupri context
- * @bootmem: true if allocations need to use bootmem
  *
  * Returns: -ENOMEM if memory fails.
  */
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 84adb2d66cbd..7c6414fc669d 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4866,6 +4866,15 @@ static void nohz_balancer_kick(int cpu)
         return;
 }
 
+static inline void clear_nohz_tick_stopped(int cpu)
+{
+        if (unlikely(test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))) {
+                cpumask_clear_cpu(cpu, nohz.idle_cpus_mask);
+                atomic_dec(&nohz.nr_cpus);
+                clear_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu));
+        }
+}
+
 static inline void set_cpu_sd_state_busy(void)
 {
         struct sched_domain *sd;
@@ -4904,6 +4913,12 @@ void select_nohz_load_balancer(int stop_tick)
 {
         int cpu = smp_processor_id();
 
+        /*
+         * If this cpu is going down, then nothing needs to be done.
+         */
+        if (!cpu_active(cpu))
+                return;
+
         if (stop_tick) {
                 if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))
                         return;
@@ -4914,6 +4929,18 @@ void select_nohz_load_balancer(int stop_tick)
         }
         return;
 }
+
+static int __cpuinit sched_ilb_notifier(struct notifier_block *nfb,
+                                        unsigned long action, void *hcpu)
+{
+        switch (action & ~CPU_TASKS_FROZEN) {
+        case CPU_DYING:
+                clear_nohz_tick_stopped(smp_processor_id());
+                return NOTIFY_OK;
+        default:
+                return NOTIFY_DONE;
+        }
+}
 #endif
 
 static DEFINE_SPINLOCK(balancing);
@@ -5070,11 +5097,7 @@ static inline int nohz_kick_needed(struct rq *rq, int cpu)
         * busy tick after returning from idle, we will update the busy stats.
         */
         set_cpu_sd_state_busy();
-        if (unlikely(test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))) {
-                clear_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu));
-                cpumask_clear_cpu(cpu, nohz.idle_cpus_mask);
-                atomic_dec(&nohz.nr_cpus);
-        }
+        clear_nohz_tick_stopped(cpu);
 
         /*
          * None are in tickless mode and hence no need for NOHZ idle load
@@ -5590,6 +5613,7 @@ __init void init_sched_fair_class(void)
 
 #ifdef CONFIG_NO_HZ
         zalloc_cpumask_var(&nohz.idle_cpus_mask, GFP_NOWAIT);
+        cpu_notifier(sched_ilb_notifier, 0);
 #endif
 #endif /* SMP */
 
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 3640ebbb466b..f42ae7fb5ec5 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1587,6 +1587,11 @@ static int push_rt_task(struct rq *rq)
         if (!next_task)
                 return 0;
 
+#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
+       if (unlikely(task_running(rq, next_task)))
+               return 0;
+#endif
+
 retry:
         if (unlikely(next_task == rq->curr)) {
                 WARN_ON(1);
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 1d7bca7f4f52..d117262deba3 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -296,7 +296,7 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
                 if (__this_cpu_read(soft_watchdog_warn) == true)
                         return HRTIMER_RESTART;
 
-                printk(KERN_ERR "BUG: soft lockup - CPU#%d stuck for %us! [%s:%d]\n",
+                printk(KERN_EMERG "BUG: soft lockup - CPU#%d stuck for %us! [%s:%d]\n",
                         smp_processor_id(), duration,
                         current->comm, task_pid_nr(current));
                 print_modules();