12 files changed, 336 insertions, 249 deletions

diff --git a/fs/proc/array.c b/fs/proc/array.c
index 4badde179b18..f560325c444f 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -134,13 +134,16 @@ static inline void task_name(struct seq_file *m, struct task_struct *p)
  * simple bit tests.
  */
 static const char *task_state_array[] = {
-        "R (running)",          /*  0 */
-        "S (sleeping)",         /*  1 */
-        "D (disk sleep)",       /*  2 */
-        "T (stopped)",          /*  4 */
-        "T (tracing stop)",     /*  8 */
-        "Z (zombie)",           /* 16 */
-        "X (dead)"              /* 32 */
+        "R (running)",          /*   0 */
+        "S (sleeping)",         /*   1 */
+        "D (disk sleep)",       /*   2 */
+        "T (stopped)",          /*   4 */
+        "t (tracing stop)",     /*   8 */
+        "Z (zombie)",           /*  16 */
+        "X (dead)",             /*  32 */
+        "x (dead)",             /*  64 */
+        "K (wakekill)",         /* 128 */
+        "W (waking)",           /* 256 */
 };
 
 static inline const char *get_task_state(struct task_struct *tsk)
@@ -148,6 +151,8 @@ static inline const char *get_task_state(struct task_struct *tsk)
         unsigned int state = (tsk->state & TASK_REPORT) | tsk->exit_state;
         const char **p = &task_state_array[0];
 
+        BUILD_BUG_ON(1 + ilog2(TASK_STATE_MAX) != ARRAY_SIZE(task_state_array));
+
         while (state) {
                 p++;
                 state >>= 1;
diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h
index c4ba9a78721e..96cc307ed9f4 100644
--- a/include/linux/rcutiny.h
+++ b/include/linux/rcutiny.h
@@ -101,4 +101,9 @@ static inline void exit_rcu(void)
 {
 }
 
+static inline int rcu_preempt_depth(void)
+{
+        return 0;
+}
+
 #endif /* __LINUX_RCUTINY_H */
diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h
index c93eee5911b0..8044b1b94333 100644
--- a/include/linux/rcutree.h
+++ b/include/linux/rcutree.h
@@ -45,6 +45,12 @@ extern void __rcu_read_unlock(void);
 extern void synchronize_rcu(void);
 extern void exit_rcu(void);
 
+/*
+ * Defined as macro as it is a very low level header
+ * included from areas that don't even know about current
+ */
+#define rcu_preempt_depth() (current->rcu_read_lock_nesting)
+
 #else /* #ifdef CONFIG_TREE_PREEMPT_RCU */
 
 static inline void __rcu_read_lock(void)
@@ -63,6 +69,11 @@ static inline void exit_rcu(void)
 {
 }
 
+static inline int rcu_preempt_depth(void)
+{
+        return 0;
+}
+
 #endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */
 
 static inline void __rcu_read_lock_bh(void)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index e89857812be6..f2f842db03ce 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -192,6 +192,12 @@ print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
 #define TASK_DEAD               64
 #define TASK_WAKEKILL           128
 #define TASK_WAKING             256
+#define TASK_STATE_MAX          512
+
+#define TASK_STATE_TO_CHAR_STR "RSDTtZXxKW"
+
+extern char ___assert_task_state[1 - 2*!!(
+                sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1)];
 
 /* Convenience macros for the sake of set_task_state */
 #define TASK_KILLABLE           (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
@@ -1091,7 +1097,8 @@ struct sched_class {
                               enum cpu_idle_type idle);
         void (*pre_schedule) (struct rq *this_rq, struct task_struct *task);
         void (*post_schedule) (struct rq *this_rq);
-        void (*task_wake_up) (struct rq *this_rq, struct task_struct *task);
+        void (*task_waking) (struct rq *this_rq, struct task_struct *task);
+        void (*task_woken) (struct rq *this_rq, struct task_struct *task);
 
         void (*set_cpus_allowed)(struct task_struct *p,
                                  const struct cpumask *newmask);
@@ -1115,7 +1122,7 @@ struct sched_class {
                                          struct task_struct *task);
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
-        void (*moved_group) (struct task_struct *p);
+        void (*moved_group) (struct task_struct *p, int on_rq);
 #endif
 };
 
@@ -2594,8 +2601,6 @@ static inline void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
 }
 #endif /* CONFIG_MM_OWNER */
 
-#define TASK_STATE_TO_CHAR_STR "RSDTtZX"
-
 #endif /* __KERNEL__ */
 
 #endif
diff --git a/init/main.c b/init/main.c
index c3db4a98b369..dac44a9356a5 100644
--- a/init/main.c
+++ b/init/main.c
@@ -369,12 +369,6 @@ static void __init smp_init(void)
 {
         unsigned int cpu;
 
-        /*
-         * Set up the current CPU as possible to migrate to.
-         * The other ones will be done by cpu_up/cpu_down()
-         */
-        set_cpu_active(smp_processor_id(), true);
-
         /* FIXME: This should be done in userspace --RR */
         for_each_present_cpu(cpu) {
                 if (num_online_cpus() >= setup_max_cpus)
@@ -486,6 +480,7 @@ static void __init boot_cpu_init(void)
         int cpu = smp_processor_id();
         /* Mark the boot cpu "present", "online" etc for SMP and UP case */
         set_cpu_online(cpu, true);
+        set_cpu_active(cpu, true);
         set_cpu_present(cpu, true);
         set_cpu_possible(cpu, true);
 }
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 291ac586f37f..1c8ddd6ee940 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -209,6 +209,7 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
                 return -ENOMEM;
 
         cpu_hotplug_begin();
+        set_cpu_active(cpu, false);
         err = __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE | mod,
                                         hcpu, -1, &nr_calls);
         if (err == NOTIFY_BAD) {
@@ -280,18 +281,6 @@ int __ref cpu_down(unsigned int cpu)
                 goto out;
         }
 
-        set_cpu_active(cpu, false);
-
-        /*
-         * Make sure the all cpus did the reschedule and are not
-         * using stale version of the cpu_active_mask.
-         * This is not strictly necessary becuase stop_machine()
-         * that we run down the line already provides the required
-         * synchronization. But it's really a side effect and we do not
-         * want to depend on the innards of the stop_machine here.
-         */
-        synchronize_sched();
-
         err = _cpu_down(cpu, 0);
 
 out:
@@ -382,19 +371,12 @@ int disable_nonboot_cpus(void)
                 return error;
         cpu_maps_update_begin();
         first_cpu = cpumask_first(cpu_online_mask);
-        /* We take down all of the non-boot CPUs in one shot to avoid races
+        /*
+         * We take down all of the non-boot CPUs in one shot to avoid races
          * with the userspace trying to use the CPU hotplug at the same time
          */
         cpumask_clear(frozen_cpus);
 
-        for_each_online_cpu(cpu) {
-                if (cpu == first_cpu)
-                        continue;
-                set_cpu_active(cpu, false);
-        }
-
-        synchronize_sched();
-
         printk("Disabling non-boot CPUs ...\n");
         for_each_online_cpu(cpu) {
                 if (cpu == first_cpu)
diff --git a/kernel/kthread.c b/kernel/kthread.c
index ab7ae57773e1..fbb6222fe7e0 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -150,6 +150,29 @@ struct task_struct *kthread_create(int (*threadfn)(void *data),
 EXPORT_SYMBOL(kthread_create);
 
 /**
+ * kthread_bind - bind a just-created kthread to a cpu.
+ * @p: thread created by kthread_create().
+ * @cpu: cpu (might not be online, must be possible) for @k to run on.
+ *
+ * Description: This function is equivalent to set_cpus_allowed(),
+ * except that @cpu doesn't need to be online, and the thread must be
+ * stopped (i.e., just returned from kthread_create()).
+ */
+void kthread_bind(struct task_struct *p, unsigned int cpu)
+{
+        /* Must have done schedule() in kthread() before we set_task_cpu */
+        if (!wait_task_inactive(p, TASK_UNINTERRUPTIBLE)) {
+                WARN_ON(1);
+                return;
+        }
+
+        p->cpus_allowed = cpumask_of_cpu(cpu);
+        p->rt.nr_cpus_allowed = 1;
+        p->flags |= PF_THREAD_BOUND;
+}
+EXPORT_SYMBOL(kthread_bind);
+
+/**
  * kthread_stop - stop a thread created by kthread_create().
  * @k: thread created by kthread_create().
  *
diff --git a/kernel/sched.c b/kernel/sched.c
index 18cceeecce35..720df108a2d6 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -26,6 +26,8 @@
  *              Thomas Gleixner, Mike Kravetz
  */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/nmi.h>
@@ -2002,39 +2004,6 @@ static inline void check_class_changed(struct rq *rq, struct task_struct *p,
                 p->sched_class->prio_changed(rq, p, oldprio, running);
 }
 
-/**
- * kthread_bind - bind a just-created kthread to a cpu.
- * @p: thread created by kthread_create().
- * @cpu: cpu (might not be online, must be possible) for @k to run on.
- *
- * Description: This function is equivalent to set_cpus_allowed(),
- * except that @cpu doesn't need to be online, and the thread must be
- * stopped (i.e., just returned from kthread_create()).
- *
- * Function lives here instead of kthread.c because it messes with
- * scheduler internals which require locking.
- */
-void kthread_bind(struct task_struct *p, unsigned int cpu)
-{
-        struct rq *rq = cpu_rq(cpu);
-        unsigned long flags;
-
-        /* Must have done schedule() in kthread() before we set_task_cpu */
-        if (!wait_task_inactive(p, TASK_UNINTERRUPTIBLE)) {
-                WARN_ON(1);
-                return;
-        }
-
-        raw_spin_lock_irqsave(&rq->lock, flags);
-        update_rq_clock(rq);
-        set_task_cpu(p, cpu);
-        p->cpus_allowed = cpumask_of_cpu(cpu);
-        p->rt.nr_cpus_allowed = 1;
-        p->flags |= PF_THREAD_BOUND;
-        raw_spin_unlock_irqrestore(&rq->lock, flags);
-}
-EXPORT_SYMBOL(kthread_bind);
-
 #ifdef CONFIG_SMP
 /*
  * Is this task likely cache-hot:
@@ -2044,6 +2013,9 @@ task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
 {
         s64 delta;
 
+        if (p->sched_class != &fair_sched_class)
+                return 0;
+
         /*
          * Buddy candidates are cache hot:
          */
@@ -2052,9 +2024,6 @@ task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
                          &p->se == cfs_rq_of(&p->se)->last))
                 return 1;
 
-        if (p->sched_class != &fair_sched_class)
-                return 0;
-
         if (sysctl_sched_migration_cost == -1)
                 return 1;
         if (sysctl_sched_migration_cost == 0)
@@ -2065,22 +2034,24 @@ task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
         return delta < (s64)sysctl_sched_migration_cost;
 }
 
-
 void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
 {
-        int old_cpu = task_cpu(p);
-        struct cfs_rq *old_cfsrq = task_cfs_rq(p),
-                      *new_cfsrq = cpu_cfs_rq(old_cfsrq, new_cpu);
+#ifdef CONFIG_SCHED_DEBUG
+        /*
+         * We should never call set_task_cpu() on a blocked task,
+         * ttwu() will sort out the placement.
+         */
+        WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING &&
+                        !(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE));
+#endif
 
         trace_sched_migrate_task(p, new_cpu);
 
-        if (old_cpu != new_cpu) {
-                p->se.nr_migrations++;
-                perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS,
-                                     1, 1, NULL, 0);
-        }
-        p->se.vruntime -= old_cfsrq->min_vruntime -
-                                         new_cfsrq->min_vruntime;
+        if (task_cpu(p) == new_cpu)
+                return;
+
+        p->se.nr_migrations++;
+        perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, 1, NULL, 0);
 
         __set_task_cpu(p, new_cpu);
 }
@@ -2105,13 +2076,10 @@ migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req)
 
         /*
          * If the task is not on a runqueue (and not running), then
-         * it is sufficient to simply update the task's cpu field.
+         * the next wake-up will properly place the task.
          */
-        if (!p->se.on_rq && !task_running(rq, p)) {
-                update_rq_clock(rq);
-                set_task_cpu(p, dest_cpu);
+        if (!p->se.on_rq && !task_running(rq, p))
                 return 0;
-        }
 
         init_completion(&req->done);
         req->task = p;
@@ -2317,10 +2285,73 @@ void task_oncpu_function_call(struct task_struct *p,
 }
 
 #ifdef CONFIG_SMP
+static int select_fallback_rq(int cpu, struct task_struct *p)
+{
+        int dest_cpu;
+        const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(cpu));
+
+        /* Look for allowed, online CPU in same node. */
+        for_each_cpu_and(dest_cpu, nodemask, cpu_active_mask)
+                if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed))
+                        return dest_cpu;
+
+        /* Any allowed, online CPU? */
+        dest_cpu = cpumask_any_and(&p->cpus_allowed, cpu_active_mask);
+        if (dest_cpu < nr_cpu_ids)
+                return dest_cpu;
+
+        /* No more Mr. Nice Guy. */
+        if (dest_cpu >= nr_cpu_ids) {
+                rcu_read_lock();
+                cpuset_cpus_allowed_locked(p, &p->cpus_allowed);
+                rcu_read_unlock();
+                dest_cpu = cpumask_any_and(cpu_active_mask, &p->cpus_allowed);
+
+                /*
+                 * Don't tell them about moving exiting tasks or
+                 * kernel threads (both mm NULL), since they never
+                 * leave kernel.
+                 */
+                if (p->mm && printk_ratelimit()) {
+                        printk(KERN_INFO "process %d (%s) no "
+                               "longer affine to cpu%d\n",
+                               task_pid_nr(p), p->comm, cpu);
+                }
+        }
+
+        return dest_cpu;
+}
+
+/*
+ * Called from:
+ *
+ *  - fork, @p is stable because it isn't on the tasklist yet
+ *
+ *  - exec, @p is unstable, retry loop
+ *
+ *  - wake-up, we serialize ->cpus_allowed against TASK_WAKING so
+ *             we should be good.
+ */
 static inline
 int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags)
 {
-        return p->sched_class->select_task_rq(p, sd_flags, wake_flags);
+        int cpu = p->sched_class->select_task_rq(p, sd_flags, wake_flags);
+
+        /*
+         * In order not to call set_task_cpu() on a blocking task we need
+         * to rely on ttwu() to place the task on a valid ->cpus_allowed
+         * cpu.
+         *
+         * Since this is common to all placement strategies, this lives here.
+         *
+         * [ this allows ->select_task() to simply return task_cpu(p) and
+         *   not worry about this generic constraint ]
+         */
+        if (unlikely(!cpumask_test_cpu(cpu, &p->cpus_allowed) ||
+                     !cpu_active(cpu)))
+                cpu = select_fallback_rq(task_cpu(p), p);
+
+        return cpu;
 }
 #endif
 
@@ -2375,6 +2406,10 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
         if (task_contributes_to_load(p))
                 rq->nr_uninterruptible--;
         p->state = TASK_WAKING;
+
+        if (p->sched_class->task_waking)
+                p->sched_class->task_waking(rq, p);
+
         __task_rq_unlock(rq);
 
         cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags);
@@ -2438,8 +2473,8 @@ out_running:
 
         p->state = TASK_RUNNING;
 #ifdef CONFIG_SMP
-        if (p->sched_class->task_wake_up)
-                p->sched_class->task_wake_up(rq, p);
+        if (p->sched_class->task_woken)
+                p->sched_class->task_woken(rq, p);
 
         if (unlikely(rq->idle_stamp)) {
                 u64 delta = rq->clock - rq->idle_stamp;
@@ -2538,14 +2573,6 @@ static void __sched_fork(struct task_struct *p)
 #ifdef CONFIG_PREEMPT_NOTIFIERS
         INIT_HLIST_HEAD(&p->preempt_notifiers);
 #endif
-
-        /*
-         * We mark the process as running here, but have not actually
-         * inserted it onto the runqueue yet. This guarantees that
-         * nobody will actually run it, and a signal or other external
-         * event cannot wake it up and insert it on the runqueue either.
-         */
-        p->state = TASK_RUNNING;
 }
 
 /*
@@ -2556,6 +2583,12 @@ void sched_fork(struct task_struct *p, int clone_flags)
         int cpu = get_cpu();
 
         __sched_fork(p);
+        /*
+         * We mark the process as waking here. This guarantees that
+         * nobody will actually run it, and a signal or other external
+         * event cannot wake it up and insert it on the runqueue either.
+         */
+        p->state = TASK_WAKING;
 
         /*
          * Revert to default priority/policy on fork if requested.
@@ -2624,14 +2657,15 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
         struct rq *rq;
 
         rq = task_rq_lock(p, &flags);
-        BUG_ON(p->state != TASK_RUNNING);
+        BUG_ON(p->state != TASK_WAKING);
+        p->state = TASK_RUNNING;
         update_rq_clock(rq);
         activate_task(rq, p, 0);
         trace_sched_wakeup_new(rq, p, 1);
         check_preempt_curr(rq, p, WF_FORK);
 #ifdef CONFIG_SMP
-        if (p->sched_class->task_wake_up)
-                p->sched_class->task_wake_up(rq, p);
+        if (p->sched_class->task_woken)
+                p->sched_class->task_woken(rq, p);
 #endif
         task_rq_unlock(rq, &flags);
 }
@@ -3101,21 +3135,36 @@ static void double_rq_unlock(struct rq *rq1, struct rq *rq2)
 }
 
 /*
- * If dest_cpu is allowed for this process, migrate the task to it.
- * This is accomplished by forcing the cpu_allowed mask to only
- * allow dest_cpu, which will force the cpu onto dest_cpu. Then
- * the cpu_allowed mask is restored.
+ * sched_exec - execve() is a valuable balancing opportunity, because at
+ * this point the task has the smallest effective memory and cache footprint.
  */
-static void sched_migrate_task(struct task_struct *p, int dest_cpu)
+void sched_exec(void)
 {
+        struct task_struct *p = current;
         struct migration_req req;
+        int dest_cpu, this_cpu;
         unsigned long flags;
         struct rq *rq;
 
+again:
+        this_cpu = get_cpu();
+        dest_cpu = select_task_rq(p, SD_BALANCE_EXEC, 0);
+        if (dest_cpu == this_cpu) {
+                put_cpu();
+                return;
+        }
+
         rq = task_rq_lock(p, &flags);
+        put_cpu();
+
+        /*
+         * select_task_rq() can race against ->cpus_allowed
+         */
         if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed)
-            || unlikely(!cpu_active(dest_cpu)))
-                goto out;
+            || unlikely(!cpu_active(dest_cpu))) {
+                task_rq_unlock(rq, &flags);
+                goto again;
+        }
 
         /* force the process onto the specified CPU */
         if (migrate_task(p, dest_cpu, &req)) {
@@ -3130,24 +3179,10 @@ static void sched_migrate_task(struct task_struct *p, int dest_cpu)
 
                 return;
         }
-out:
         task_rq_unlock(rq, &flags);
 }
 
 /*
- * sched_exec - execve() is a valuable balancing opportunity, because at
- * this point the task has the smallest effective memory and cache footprint.
- */
-void sched_exec(void)
-{
-        int new_cpu, this_cpu = get_cpu();
-        new_cpu = select_task_rq(current, SD_BALANCE_EXEC, 0);
-        put_cpu();
-        if (new_cpu != this_cpu)
-                sched_migrate_task(current, new_cpu);
-}
-
-/*
  * pull_task - move a task from a remote runqueue to the local runqueue.
  * Both runqueues must be locked.
  */
@@ -5340,8 +5375,8 @@ static noinline void __schedule_bug(struct task_struct *prev)
 {
         struct pt_regs *regs = get_irq_regs();
 
-        printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n",
-                prev->comm, prev->pid, preempt_count());
+        pr_err("BUG: scheduling while atomic: %s/%d/0x%08x\n",
+               prev->comm, prev->pid, preempt_count());
 
         debug_show_held_locks(prev);
         print_modules();
@@ -5911,14 +5946,15 @@ EXPORT_SYMBOL(wait_for_completion_killable);
  */
 bool try_wait_for_completion(struct completion *x)
 {
+        unsigned long flags;
         int ret = 1;
 
-        spin_lock_irq(&x->wait.lock);
+        spin_lock_irqsave(&x->wait.lock, flags);
         if (!x->done)
                 ret = 0;
         else
                 x->done--;
-        spin_unlock_irq(&x->wait.lock);
+        spin_unlock_irqrestore(&x->wait.lock, flags);
         return ret;
 }
 EXPORT_SYMBOL(try_wait_for_completion);
@@ -5933,12 +5969,13 @@ EXPORT_SYMBOL(try_wait_for_completion);
  */
 bool completion_done(struct completion *x)
 {
+        unsigned long flags;
         int ret = 1;
 
-        spin_lock_irq(&x->wait.lock);
+        spin_lock_irqsave(&x->wait.lock, flags);
         if (!x->done)
                 ret = 0;
-        spin_unlock_irq(&x->wait.lock);
+        spin_unlock_irqrestore(&x->wait.lock, flags);
         return ret;
 }
 EXPORT_SYMBOL(completion_done);
@@ -6457,7 +6494,7 @@ SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid)
                 return -EINVAL;
 
         retval = -ESRCH;
-        read_lock(&tasklist_lock);
+        rcu_read_lock();
         p = find_process_by_pid(pid);
         if (p) {
                 retval = security_task_getscheduler(p);
@@ -6465,7 +6502,7 @@ SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid)
                         retval = p->policy
                                 | (p->sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0);
         }
-        read_unlock(&tasklist_lock);
+        rcu_read_unlock();
         return retval;
 }
 
@@ -6483,7 +6520,7 @@ SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param)
         if (!param || pid < 0)
                 return -EINVAL;
 
-        read_lock(&tasklist_lock);
+        rcu_read_lock();
         p = find_process_by_pid(pid);
         retval = -ESRCH;
         if (!p)
@@ -6494,7 +6531,7 @@ SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param)
                 goto out_unlock;
 
         lp.sched_priority = p->rt_priority;
-        read_unlock(&tasklist_lock);
+        rcu_read_unlock();
 
         /*
          * This one might sleep, we cannot do it with a spinlock held ...
@@ -6504,7 +6541,7 @@ SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param)
         return retval;
 
 out_unlock:
-        read_unlock(&tasklist_lock);
+        rcu_read_unlock();
         return retval;
 }
 
@@ -6515,22 +6552,18 @@ long sched_setaffinity(pid_t pid, const struct cpumask *in_mask)
         int retval;
 
         get_online_cpus();
-        read_lock(&tasklist_lock);
+        rcu_read_lock();
 
         p = find_process_by_pid(pid);
         if (!p) {
-                read_unlock(&tasklist_lock);
+                rcu_read_unlock();
                 put_online_cpus();
                 return -ESRCH;
         }
 
-        /*
-         * It is not safe to call set_cpus_allowed with the
-         * tasklist_lock held. We will bump the task_struct's
-         * usage count and then drop tasklist_lock.
-         */
+        /* Prevent p going away */
         get_task_struct(p);
-        read_unlock(&tasklist_lock);
+        rcu_read_unlock();
 
         if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) {
                 retval = -ENOMEM;
@@ -6616,7 +6649,7 @@ long sched_getaffinity(pid_t pid, struct cpumask *mask)
         int retval;
 
         get_online_cpus();
-        read_lock(&tasklist_lock);
+        rcu_read_lock();
 
         retval = -ESRCH;
         p = find_process_by_pid(pid);
@@ -6632,7 +6665,7 @@ long sched_getaffinity(pid_t pid, struct cpumask *mask)
         task_rq_unlock(rq, &flags);
 
 out_unlock:
-        read_unlock(&tasklist_lock);
+        rcu_read_unlock();
         put_online_cpus();
 
         return retval;
@@ -6876,7 +6909,7 @@ SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
                 return -EINVAL;
 
         retval = -ESRCH;
-        read_lock(&tasklist_lock);
+        rcu_read_lock();
         p = find_process_by_pid(pid);
         if (!p)
                 goto out_unlock;
@@ -6889,13 +6922,13 @@ SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
         time_slice = p->sched_class->get_rr_interval(rq, p);
         task_rq_unlock(rq, &flags);
 
-        read_unlock(&tasklist_lock);
+        rcu_read_unlock();
         jiffies_to_timespec(time_slice, &t);
         retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0;
         return retval;
 
 out_unlock:
-        read_unlock(&tasklist_lock);
+        rcu_read_unlock();
         return retval;
 }
 
@@ -6907,23 +6940,23 @@ void sched_show_task(struct task_struct *p)
         unsigned state;
 
         state = p->state ? __ffs(p->state) + 1 : 0;
-        printk(KERN_INFO "%-13.13s %c", p->comm,
+        pr_info("%-13.13s %c", p->comm,
                 state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?');
 #if BITS_PER_LONG == 32
         if (state == TASK_RUNNING)
-                printk(KERN_CONT " running  ");
+                pr_cont(" running  ");
         else
-                printk(KERN_CONT " %08lx ", thread_saved_pc(p));
+                pr_cont(" %08lx ", thread_saved_pc(p));
 #else
         if (state == TASK_RUNNING)
-                printk(KERN_CONT "  running task    ");
+                pr_cont("  running task    ");
         else
-                printk(KERN_CONT " %016lx ", thread_saved_pc(p));
+                pr_cont(" %016lx ", thread_saved_pc(p));
 #endif
 #ifdef CONFIG_DEBUG_STACK_USAGE
         free = stack_not_used(p);
 #endif
-        printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free,
+        pr_cont("%5lu %5d %6d 0x%08lx\n", free,
                 task_pid_nr(p), task_pid_nr(p->real_parent),
                 (unsigned long)task_thread_info(p)->flags);
 
@@ -6935,11 +6968,9 @@ void show_state_filter(unsigned long state_filter)
         struct task_struct *g, *p;
 
 #if BITS_PER_LONG == 32
-        printk(KERN_INFO
-                "  task                PC stack   pid father\n");
+        pr_info("  task                PC stack   pid father\n");
 #else
-        printk(KERN_INFO
-                "  task                        PC stack   pid father\n");
+        pr_info("  task                        PC stack   pid father\n");
 #endif
         read_lock(&tasklist_lock);
         do_each_thread(g, p) {
@@ -6986,6 +7017,7 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu)
         raw_spin_lock_irqsave(&rq->lock, flags);
 
         __sched_fork(idle);
+        idle->state = TASK_RUNNING;
         idle->se.exec_start = sched_clock();
 
         cpumask_copy(&idle->cpus_allowed, cpumask_of(cpu));
@@ -7100,7 +7132,23 @@ int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
         struct rq *rq;
         int ret = 0;
 
+        /*
+         * Since we rely on wake-ups to migrate sleeping tasks, don't change
+         * the ->cpus_allowed mask from under waking tasks, which would be
+         * possible when we change rq->lock in ttwu(), so synchronize against
+         * TASK_WAKING to avoid that.
+         */
+again:
+        while (p->state == TASK_WAKING)
+                cpu_relax();
+
         rq = task_rq_lock(p, &flags);
+
+        if (p->state == TASK_WAKING) {
+                task_rq_unlock(rq, &flags);
+                goto again;
+        }
+
         if (!cpumask_intersects(new_mask, cpu_active_mask)) {
                 ret = -EINVAL;
                 goto out;
@@ -7156,7 +7204,7 @@ EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr);
 static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu)
 {
         struct rq *rq_dest, *rq_src;
-        int ret = 0, on_rq;
+        int ret = 0;
 
         if (unlikely(!cpu_active(dest_cpu)))
                 return ret;
@@ -7172,12 +7220,13 @@ static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu)
         if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed))
                 goto fail;
 
-        on_rq = p->se.on_rq;
-        if (on_rq)
+        /*
+         * If we're not on a rq, the next wake-up will ensure we're
+         * placed properly.
+         */
+        if (p->se.on_rq) {
                 deactivate_task(rq_src, p, 0);
-
-        set_task_cpu(p, dest_cpu);
-        if (on_rq) {
+                set_task_cpu(p, dest_cpu);
                 activate_task(rq_dest, p, 0);
                 check_preempt_curr(rq_dest, p, 0);
         }
@@ -7273,37 +7322,10 @@ static int __migrate_task_irq(struct task_struct *p, int src_cpu, int dest_cpu)
 static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p)
 {
         int dest_cpu;
-        const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(dead_cpu));
 
 again:
-        /* Look for allowed, online CPU in same node. */
-        for_each_cpu_and(dest_cpu, nodemask, cpu_active_mask)
-                if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed))
-                        goto move;
-
-        /* Any allowed, online CPU? */
-        dest_cpu = cpumask_any_and(&p->cpus_allowed, cpu_active_mask);
-        if (dest_cpu < nr_cpu_ids)
-                goto move;
-
-        /* No more Mr. Nice Guy. */
-        if (dest_cpu >= nr_cpu_ids) {
-                cpuset_cpus_allowed_locked(p, &p->cpus_allowed);
-                dest_cpu = cpumask_any_and(cpu_active_mask, &p->cpus_allowed);
-
-                /*
-                 * Don't tell them about moving exiting tasks or
-                 * kernel threads (both mm NULL), since they never
-                 * leave kernel.
-                 */
-                if (p->mm && printk_ratelimit()) {
-                        printk(KERN_INFO "process %d (%s) no "
-                               "longer affine to cpu%d\n",
-                               task_pid_nr(p), p->comm, dead_cpu);
-                }
-        }
+        dest_cpu = select_fallback_rq(dead_cpu, p);
 
-move:
         /* It can have affinity changed while we were choosing. */
         if (unlikely(!__migrate_task_irq(p, dead_cpu, dest_cpu)))
                 goto again;
@@ -7806,48 +7828,44 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
         printk(KERN_DEBUG "%*s domain %d: ", level, "", level);
 
         if (!(sd->flags & SD_LOAD_BALANCE)) {
-                printk("does not load-balance\n");
+                pr_cont("does not load-balance\n");
                 if (sd->parent)
-                        printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain"
-                                        " has parent");
+                        pr_err("ERROR: !SD_LOAD_BALANCE domain has parent\n");
                 return -1;
         }
 
-        printk(KERN_CONT "span %s level %s\n", str, sd->name);
+        pr_cont("span %s level %s\n", str, sd->name);
 
         if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) {
-                printk(KERN_ERR "ERROR: domain->span does not contain "
-                                "CPU%d\n", cpu);
+                pr_err("ERROR: domain->span does not contain CPU%d\n", cpu);
         }
         if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) {
-                printk(KERN_ERR "ERROR: domain->groups does not contain"
-                                " CPU%d\n", cpu);
+                pr_err("ERROR: domain->groups does not contain CPU%d\n", cpu);
         }
 
         printk(KERN_DEBUG "%*s groups:", level + 1, "");
         do {
                 if (!group) {
-                        printk("\n");
-                        printk(KERN_ERR "ERROR: group is NULL\n");
+                        pr_cont("\n");
+                        pr_err("ERROR: group is NULL\n");
                         break;
                 }
 
                 if (!group->cpu_power) {
-                        printk(KERN_CONT "\n");
-                        printk(KERN_ERR "ERROR: domain->cpu_power not "
-                                        "set\n");
+                        pr_cont("\n");
+                        pr_err("ERROR: domain->cpu_power not set\n");
                         break;
                 }
 
                 if (!cpumask_weight(sched_group_cpus(group))) {
-                        printk(KERN_CONT "\n");
-                        printk(KERN_ERR "ERROR: empty group\n");
+                        pr_cont("\n");
+                        pr_err("ERROR: empty group\n");
                         break;
                 }
 
                 if (cpumask_intersects(groupmask, sched_group_cpus(group))) {
-                        printk(KERN_CONT "\n");
-                        printk(KERN_ERR "ERROR: repeated CPUs\n");
+                        pr_cont("\n");
+                        pr_err("ERROR: repeated CPUs\n");
                         break;
                 }
 
@@ -7855,23 +7873,21 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
 
                 cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group));
 
-                printk(KERN_CONT " %s", str);
+                pr_cont(" %s", str);
                 if (group->cpu_power != SCHED_LOAD_SCALE) {
-                        printk(KERN_CONT " (cpu_power = %d)",
-                                group->cpu_power);
+                        pr_cont(" (cpu_power = %d)", group->cpu_power);
                 }
 
                 group = group->next;
         } while (group != sd->groups);
-        printk(KERN_CONT "\n");
+        pr_cont("\n");
 
         if (!cpumask_equal(sched_domain_span(sd), groupmask))
-                printk(KERN_ERR "ERROR: groups don't span domain->span\n");
+                pr_err("ERROR: groups don't span domain->span\n");
 
         if (sd->parent &&
             !cpumask_subset(groupmask, sched_domain_span(sd->parent)))
-                printk(KERN_ERR "ERROR: parent span is not a superset "
-                        "of domain->span\n");
+                pr_err("ERROR: parent span is not a superset of domain->span\n");
         return 0;
 }
 
@@ -8427,8 +8443,7 @@ static int build_numa_sched_groups(struct s_data *d,
         sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(),
                           GFP_KERNEL, num);
         if (!sg) {
-                printk(KERN_WARNING "Can not alloc domain group for node %d\n",
-                       num);
+                pr_warning("Can not alloc domain group for node %d\n", num);
                 return -ENOMEM;
         }
         d->sched_group_nodes[num] = sg;
@@ -8457,8 +8472,8 @@ static int build_numa_sched_groups(struct s_data *d,
                 sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(),
                                   GFP_KERNEL, num);
                 if (!sg) {
-                        printk(KERN_WARNING
-                               "Can not alloc domain group for node %d\n", j);
+                        pr_warning("Can not alloc domain group for node %d\n",
+                                   j);
                         return -ENOMEM;
                 }
                 sg->cpu_power = 0;
@@ -8686,7 +8701,7 @@ static enum s_alloc __visit_domain_allocation_hell(struct s_data *d,
         d->sched_group_nodes = kcalloc(nr_node_ids,
                                       sizeof(struct sched_group *), GFP_KERNEL);
         if (!d->sched_group_nodes) {
-                printk(KERN_WARNING "Can not alloc sched group node list\n");
+                pr_warning("Can not alloc sched group node list\n");
                 return sa_notcovered;
         }
         sched_group_nodes_bycpu[cpumask_first(cpu_map)] = d->sched_group_nodes;
@@ -8703,7 +8718,7 @@ static enum s_alloc __visit_domain_allocation_hell(struct s_data *d,
                 return sa_send_covered;
         d->rd = alloc_rootdomain();
         if (!d->rd) {
-                printk(KERN_WARNING "Cannot alloc root domain\n");
+                pr_warning("Cannot alloc root domain\n");
                 return sa_tmpmask;
         }
         return sa_rootdomain;
@@ -9668,7 +9683,7 @@ void __init sched_init(void)
 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
 static inline int preempt_count_equals(int preempt_offset)
 {
-        int nested = preempt_count() & ~PREEMPT_ACTIVE;
+        int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth();
 
         return (nested == PREEMPT_INATOMIC_BASE + preempt_offset);
 }
@@ -9685,13 +9700,11 @@ void __might_sleep(char *file, int line, int preempt_offset)
                 return;
         prev_jiffy = jiffies;
 
-        printk(KERN_ERR
-                "BUG: sleeping function called from invalid context at %s:%d\n",
-                        file, line);
-        printk(KERN_ERR
-                "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n",
-                        in_atomic(), irqs_disabled(),
-                        current->pid, current->comm);
+        pr_err("BUG: sleeping function called from invalid context at %s:%d\n",
+               file, line);
+        pr_err("in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n",
+               in_atomic(), irqs_disabled(),
+               current->pid, current->comm);
 
         debug_show_held_locks(current);
         if (irqs_disabled())
@@ -10083,7 +10096,7 @@ void sched_move_task(struct task_struct *tsk)
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
         if (tsk->sched_class->moved_group)
-                tsk->sched_class->moved_group(tsk);
+                tsk->sched_class->moved_group(tsk, on_rq);
 #endif
 
         if (unlikely(running))
diff --git a/kernel/sched_clock.c b/kernel/sched_clock.c
index 479ce5682d7c..5b496132c28a 100644
--- a/kernel/sched_clock.c
+++ b/kernel/sched_clock.c
@@ -236,6 +236,18 @@ void sched_clock_idle_wakeup_event(u64 delta_ns)
 }
 EXPORT_SYMBOL_GPL(sched_clock_idle_wakeup_event);
 
+unsigned long long cpu_clock(int cpu)
+{
+        unsigned long long clock;
+        unsigned long flags;
+
+        local_irq_save(flags);
+        clock = sched_clock_cpu(cpu);
+        local_irq_restore(flags);
+
+        return clock;
+}
+
 #else /* CONFIG_HAVE_UNSTABLE_SCHED_CLOCK */
 
 void sched_clock_init(void)
@@ -251,17 +263,12 @@ u64 sched_clock_cpu(int cpu)
         return sched_clock();
 }
 
-#endif /* CONFIG_HAVE_UNSTABLE_SCHED_CLOCK */
 
 unsigned long long cpu_clock(int cpu)
 {
-        unsigned long long clock;
-        unsigned long flags;
+        return sched_clock_cpu(cpu);
+}
 
-        local_irq_save(flags);
-        clock = sched_clock_cpu(cpu);
-        local_irq_restore(flags);
+#endif /* CONFIG_HAVE_UNSTABLE_SCHED_CLOCK */
 
-        return clock;
-}
 EXPORT_SYMBOL_GPL(cpu_clock);
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 5bedf6e3ebf3..42ac3c9f66f6 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -510,6 +510,7 @@ __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr,
         curr->sum_exec_runtime += delta_exec;
         schedstat_add(cfs_rq, exec_clock, delta_exec);
         delta_exec_weighted = calc_delta_fair(delta_exec, curr);
+
         curr->vruntime += delta_exec_weighted;
         update_min_vruntime(cfs_rq);
 }
@@ -765,16 +766,26 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
         se->vruntime = vruntime;
 }
 
+#define ENQUEUE_WAKEUP  1
+#define ENQUEUE_MIGRATE 2
+
 static void
-enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup)
+enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 {
         /*
+         * Update the normalized vruntime before updating min_vruntime
+         * through callig update_curr().
+         */
+        if (!(flags & ENQUEUE_WAKEUP) || (flags & ENQUEUE_MIGRATE))
+                se->vruntime += cfs_rq->min_vruntime;
+
+        /*
          * Update run-time statistics of the 'current'.
          */
         update_curr(cfs_rq);
         account_entity_enqueue(cfs_rq, se);
 
-        if (wakeup) {
+        if (flags & ENQUEUE_WAKEUP) {
                 place_entity(cfs_rq, se, 0);
                 enqueue_sleeper(cfs_rq, se);
         }
@@ -828,6 +839,14 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
                 __dequeue_entity(cfs_rq, se);
         account_entity_dequeue(cfs_rq, se);
         update_min_vruntime(cfs_rq);
+
+        /*
+         * Normalize the entity after updating the min_vruntime because the
+         * update can refer to the ->curr item and we need to reflect this
+         * movement in our normalized position.
+         */
+        if (!sleep)
+                se->vruntime -= cfs_rq->min_vruntime;
 }
 
 /*
@@ -1038,13 +1057,19 @@ static void enqueue_task_fair(struct rq *rq, struct task_struct *p, int wakeup)
 {
         struct cfs_rq *cfs_rq;
         struct sched_entity *se = &p->se;
+        int flags = 0;
+
+        if (wakeup)
+                flags |= ENQUEUE_WAKEUP;
+        if (p->state == TASK_WAKING)
+                flags |= ENQUEUE_MIGRATE;
 
         for_each_sched_entity(se) {
                 if (se->on_rq)
                         break;
                 cfs_rq = cfs_rq_of(se);
-                enqueue_entity(cfs_rq, se, wakeup);
-                wakeup = 1;
+                enqueue_entity(cfs_rq, se, flags);
+                flags = ENQUEUE_WAKEUP;
         }
 
         hrtick_update(rq);
@@ -1120,6 +1145,14 @@ static void yield_task_fair(struct rq *rq)
 
 #ifdef CONFIG_SMP
 
+static void task_waking_fair(struct rq *rq, struct task_struct *p)
+{
+        struct sched_entity *se = &p->se;
+        struct cfs_rq *cfs_rq = cfs_rq_of(se);
+
+        se->vruntime -= cfs_rq->min_vruntime;
+}
+
 #ifdef CONFIG_FAIR_GROUP_SCHED
 /*
  * effective_load() calculates the load change as seen from the root_task_group
@@ -1429,6 +1462,9 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag
         }
 
         for_each_domain(cpu, tmp) {
+                if (!(tmp->flags & SD_LOAD_BALANCE))
+                        continue;
+
                 /*
                  * If power savings logic is enabled for a domain, see if we
                  * are not overloaded, if so, don't balance wider.
@@ -1975,6 +2011,8 @@ static void task_fork_fair(struct task_struct *p)
                 resched_task(rq->curr);
         }
 
+        se->vruntime -= cfs_rq->min_vruntime;
+
         raw_spin_unlock_irqrestore(&rq->lock, flags);
 }
 
@@ -2028,12 +2066,13 @@ static void set_curr_task_fair(struct rq *rq)
 }
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
-static void moved_group_fair(struct task_struct *p)
+static void moved_group_fair(struct task_struct *p, int on_rq)
 {
         struct cfs_rq *cfs_rq = task_cfs_rq(p);
 
         update_curr(cfs_rq);
-        place_entity(cfs_rq, &p->se, 1);
+        if (!on_rq)
+                place_entity(cfs_rq, &p->se, 1);
 }
 #endif
 
@@ -2073,6 +2112,8 @@ static const struct sched_class fair_sched_class = {
         .move_one_task          = move_one_task_fair,
         .rq_online              = rq_online_fair,
         .rq_offline             = rq_offline_fair,
+
+        .task_waking            = task_waking_fair,
 #endif
 
         .set_curr_task          = set_curr_task_fair,
diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c
index 5f93b570d383..21b969a28725 100644
--- a/kernel/sched_idletask.c
+++ b/kernel/sched_idletask.c
@@ -35,7 +35,7 @@ static void
 dequeue_task_idle(struct rq *rq, struct task_struct *p, int sleep)
 {
         raw_spin_unlock_irq(&rq->lock);
-        printk(KERN_ERR "bad: scheduling from the idle thread!\n");
+        pr_err("bad: scheduling from the idle thread!\n");
         dump_stack();
         raw_spin_lock_irq(&rq->lock);
 }
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index d2ea2828164e..f48328ac216f 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -1472,7 +1472,7 @@ static void post_schedule_rt(struct rq *rq)
  * If we are not running and we are not going to reschedule soon, we should
  * try to push tasks away now
  */
-static void task_wake_up_rt(struct rq *rq, struct task_struct *p)
+static void task_woken_rt(struct rq *rq, struct task_struct *p)
 {
         if (!task_running(rq, p) &&
             !test_tsk_need_resched(rq->curr) &&
@@ -1753,7 +1753,7 @@ static const struct sched_class rt_sched_class = {
         .rq_offline             = rq_offline_rt,
         .pre_schedule           = pre_schedule_rt,
         .post_schedule          = post_schedule_rt,
-        .task_wake_up           = task_wake_up_rt,
+        .task_woken             = task_woken_rt,
         .switched_from          = switched_from_rt,
 #endif