Merge branch 'sched/core' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip into trace/tip/tracing/core-4

1 files changed, 148 insertions, 202 deletions

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 5a5ea2cd924f..217e4a9393e4 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -35,8 +35,8 @@
  * (to see the precise effective timeslice length of your workload,
  *  run vmstat and monitor the context-switches (cs) field)
  */
-unsigned int sysctl_sched_latency = 5000000ULL;
-unsigned int normalized_sysctl_sched_latency = 5000000ULL;
+unsigned int sysctl_sched_latency = 6000000ULL;
+unsigned int normalized_sysctl_sched_latency = 6000000ULL;
 
 /*
  * The initial- and re-scaling of tunables is configurable
@@ -52,15 +52,15 @@ enum sched_tunable_scaling sysctl_sched_tunable_scaling
 
 /*
  * Minimal preemption granularity for CPU-bound tasks:
- * (default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds)
+ * (default: 2 msec * (1 + ilog(ncpus)), units: nanoseconds)
  */
-unsigned int sysctl_sched_min_granularity = 1000000ULL;
-unsigned int normalized_sysctl_sched_min_granularity = 1000000ULL;
+unsigned int sysctl_sched_min_granularity = 2000000ULL;
+unsigned int normalized_sysctl_sched_min_granularity = 2000000ULL;
 
 /*
  * is kept at sysctl_sched_latency / sysctl_sched_min_granularity
  */
-static unsigned int sched_nr_latency = 5;
+static unsigned int sched_nr_latency = 3;
 
 /*
  * After fork, child runs first. If set to 0 (default) then
@@ -505,7 +505,8 @@ __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr,
 {
         unsigned long delta_exec_weighted;
 
-        schedstat_set(curr->exec_max, max((u64)delta_exec, curr->exec_max));
+        schedstat_set(curr->statistics.exec_max,
+                      max((u64)delta_exec, curr->statistics.exec_max));
 
         curr->sum_exec_runtime += delta_exec;
         schedstat_add(cfs_rq, exec_clock, delta_exec);
@@ -548,7 +549,7 @@ static void update_curr(struct cfs_rq *cfs_rq)
 static inline void
 update_stats_wait_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
-        schedstat_set(se->wait_start, rq_of(cfs_rq)->clock);
+        schedstat_set(se->statistics.wait_start, rq_of(cfs_rq)->clock);
 }
 
 /*
@@ -567,18 +568,18 @@ static void update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
 static void
 update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
-        schedstat_set(se->wait_max, max(se->wait_max,
-                        rq_of(cfs_rq)->clock - se->wait_start));
-        schedstat_set(se->wait_count, se->wait_count + 1);
-        schedstat_set(se->wait_sum, se->wait_sum +
-                        rq_of(cfs_rq)->clock - se->wait_start);
+        schedstat_set(se->statistics.wait_max, max(se->statistics.wait_max,
+                        rq_of(cfs_rq)->clock - se->statistics.wait_start));
+        schedstat_set(se->statistics.wait_count, se->statistics.wait_count + 1);
+        schedstat_set(se->statistics.wait_sum, se->statistics.wait_sum +
+                        rq_of(cfs_rq)->clock - se->statistics.wait_start);
 #ifdef CONFIG_SCHEDSTATS
         if (entity_is_task(se)) {
                 trace_sched_stat_wait(task_of(se),
-                        rq_of(cfs_rq)->clock - se->wait_start);
+                        rq_of(cfs_rq)->clock - se->statistics.wait_start);
         }
 #endif
-        schedstat_set(se->wait_start, 0);
+        schedstat_set(se->statistics.wait_start, 0);
 }
 
 static inline void
@@ -657,39 +658,39 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
         if (entity_is_task(se))
                 tsk = task_of(se);
 
-        if (se->sleep_start) {
-                u64 delta = rq_of(cfs_rq)->clock - se->sleep_start;
+        if (se->statistics.sleep_start) {
+                u64 delta = rq_of(cfs_rq)->clock - se->statistics.sleep_start;
 
                 if ((s64)delta < 0)
                         delta = 0;
 
-                if (unlikely(delta > se->sleep_max))
-                        se->sleep_max = delta;
+                if (unlikely(delta > se->statistics.sleep_max))
+                        se->statistics.sleep_max = delta;
 
-                se->sleep_start = 0;
-                se->sum_sleep_runtime += delta;
+                se->statistics.sleep_start = 0;
+                se->statistics.sum_sleep_runtime += delta;
 
                 if (tsk) {
                         account_scheduler_latency(tsk, delta >> 10, 1);
                         trace_sched_stat_sleep(tsk, delta);
                 }
         }
-        if (se->block_start) {
-                u64 delta = rq_of(cfs_rq)->clock - se->block_start;
+        if (se->statistics.block_start) {
+                u64 delta = rq_of(cfs_rq)->clock - se->statistics.block_start;
 
                 if ((s64)delta < 0)
                         delta = 0;
 
-                if (unlikely(delta > se->block_max))
-                        se->block_max = delta;
+                if (unlikely(delta > se->statistics.block_max))
+                        se->statistics.block_max = delta;
 
-                se->block_start = 0;
-                se->sum_sleep_runtime += delta;
+                se->statistics.block_start = 0;
+                se->statistics.sum_sleep_runtime += delta;
 
                 if (tsk) {
                         if (tsk->in_iowait) {
-                                se->iowait_sum += delta;
-                                se->iowait_count++;
+                                se->statistics.iowait_sum += delta;
+                                se->statistics.iowait_count++;
                                 trace_sched_stat_iowait(tsk, delta);
                         }
 
@@ -737,20 +738,10 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
                 vruntime += sched_vslice(cfs_rq, se);
 
         /* sleeps up to a single latency don't count. */
-        if (!initial && sched_feat(FAIR_SLEEPERS)) {
+        if (!initial) {
                 unsigned long thresh = sysctl_sched_latency;
 
                 /*
-                 * Convert the sleeper threshold into virtual time.
-                 * SCHED_IDLE is a special sub-class.  We care about
-                 * fairness only relative to other SCHED_IDLE tasks,
-                 * all of which have the same weight.
-                 */
-                if (sched_feat(NORMALIZED_SLEEPER) && (!entity_is_task(se) ||
-                                 task_of(se)->policy != SCHED_IDLE))
-                        thresh = calc_delta_fair(thresh, se);
-
-                /*
                  * Halve their sleep time's effect, to allow
                  * for a gentler effect of sleepers:
                  */
@@ -766,9 +757,6 @@ 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 flags)
 {
@@ -776,7 +764,7 @@ 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))
+        if (!(flags & ENQUEUE_WAKEUP) || (flags & ENQUEUE_WAKING))
                 se->vruntime += cfs_rq->min_vruntime;
 
         /*
@@ -812,7 +800,7 @@ static void clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se)
 }
 
 static void
-dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
+dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 {
         /*
          * Update run-time statistics of the 'current'.
@@ -820,15 +808,15 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
         update_curr(cfs_rq);
 
         update_stats_dequeue(cfs_rq, se);
-        if (sleep) {
+        if (flags & DEQUEUE_SLEEP) {
 #ifdef CONFIG_SCHEDSTATS
                 if (entity_is_task(se)) {
                         struct task_struct *tsk = task_of(se);
 
                         if (tsk->state & TASK_INTERRUPTIBLE)
-                                se->sleep_start = rq_of(cfs_rq)->clock;
+                                se->statistics.sleep_start = rq_of(cfs_rq)->clock;
                         if (tsk->state & TASK_UNINTERRUPTIBLE)
-                                se->block_start = rq_of(cfs_rq)->clock;
+                                se->statistics.block_start = rq_of(cfs_rq)->clock;
                 }
 #endif
         }
@@ -845,7 +833,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
          * update can refer to the ->curr item and we need to reflect this
          * movement in our normalized position.
          */
-        if (!sleep)
+        if (!(flags & DEQUEUE_SLEEP))
                 se->vruntime -= cfs_rq->min_vruntime;
 }
 
@@ -912,7 +900,7 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
          * when there are only lesser-weight tasks around):
          */
         if (rq_of(cfs_rq)->load.weight >= 2*se->load.weight) {
-                se->slice_max = max(se->slice_max,
+                se->statistics.slice_max = max(se->statistics.slice_max,
                         se->sum_exec_runtime - se->prev_sum_exec_runtime);
         }
 #endif
@@ -1054,16 +1042,10 @@ static inline void hrtick_update(struct rq *rq)
  * then put the task into the rbtree:
  */
 static void
-enqueue_task_fair(struct rq *rq, struct task_struct *p, int wakeup, bool head)
+enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
 {
         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)
@@ -1081,18 +1063,18 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int wakeup, bool head)
  * decreased. We remove the task from the rbtree and
  * update the fair scheduling stats:
  */
-static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int sleep)
+static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
 {
         struct cfs_rq *cfs_rq;
         struct sched_entity *se = &p->se;
 
         for_each_sched_entity(se) {
                 cfs_rq = cfs_rq_of(se);
-                dequeue_entity(cfs_rq, se, sleep);
+                dequeue_entity(cfs_rq, se, flags);
                 /* Don't dequeue parent if it has other entities besides us */
                 if (cfs_rq->load.weight)
                         break;
-                sleep = 1;
+                flags |= DEQUEUE_SLEEP;
         }
 
         hrtick_update(rq);
@@ -1240,7 +1222,6 @@ static inline unsigned long effective_load(struct task_group *tg, int cpu,
 
 static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
 {
-        struct task_struct *curr = current;
         unsigned long this_load, load;
         int idx, this_cpu, prev_cpu;
         unsigned long tl_per_task;
@@ -1255,18 +1236,6 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
         load      = source_load(prev_cpu, idx);
         this_load = target_load(this_cpu, idx);
 
-        if (sync) {
-               if (sched_feat(SYNC_LESS) &&
-                   (curr->se.avg_overlap > sysctl_sched_migration_cost ||
-                    p->se.avg_overlap > sysctl_sched_migration_cost))
-                       sync = 0;
-        } else {
-                if (sched_feat(SYNC_MORE) &&
-                    (curr->se.avg_overlap < sysctl_sched_migration_cost &&
-                     p->se.avg_overlap < sysctl_sched_migration_cost))
-                        sync = 1;
-        }
-
         /*
          * If sync wakeup then subtract the (maximum possible)
          * effect of the currently running task from the load
@@ -1306,7 +1275,7 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
         if (sync && balanced)
                 return 1;
 
-        schedstat_inc(p, se.nr_wakeups_affine_attempts);
+        schedstat_inc(p, se.statistics.nr_wakeups_affine_attempts);
         tl_per_task = cpu_avg_load_per_task(this_cpu);
 
         if (balanced ||
@@ -1318,7 +1287,7 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
                  * there is no bad imbalance.
                  */
                 schedstat_inc(sd, ttwu_move_affine);
-                schedstat_inc(p, se.nr_wakeups_affine);
+                schedstat_inc(p, se.statistics.nr_wakeups_affine);
 
                 return 1;
         }
@@ -1406,29 +1375,48 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
 /*
  * Try and locate an idle CPU in the sched_domain.
  */
-static int
-select_idle_sibling(struct task_struct *p, struct sched_domain *sd, int target)
+static int select_idle_sibling(struct task_struct *p, int target)
 {
         int cpu = smp_processor_id();
         int prev_cpu = task_cpu(p);
+        struct sched_domain *sd;
         int i;
 
         /*
-         * If this domain spans both cpu and prev_cpu (see the SD_WAKE_AFFINE
-         * test in select_task_rq_fair) and the prev_cpu is idle then that's
-         * always a better target than the current cpu.
+         * If the task is going to be woken-up on this cpu and if it is
+         * already idle, then it is the right target.
          */
-        if (target == cpu && !cpu_rq(prev_cpu)->cfs.nr_running)
+        if (target == cpu && idle_cpu(cpu))
+                return cpu;
+
+        /*
+         * If the task is going to be woken-up on the cpu where it previously
+         * ran and if it is currently idle, then it the right target.
+         */
+        if (target == prev_cpu && idle_cpu(prev_cpu))
                 return prev_cpu;
 
         /*
-         * Otherwise, iterate the domain and find an elegible idle cpu.
+         * Otherwise, iterate the domains and find an elegible idle cpu.
          */
-        for_each_cpu_and(i, sched_domain_span(sd), &p->cpus_allowed) {
-                if (!cpu_rq(i)->cfs.nr_running) {
-                        target = i;
+        for_each_domain(target, sd) {
+                if (!(sd->flags & SD_SHARE_PKG_RESOURCES))
                         break;
+
+                for_each_cpu_and(i, sched_domain_span(sd), &p->cpus_allowed) {
+                        if (idle_cpu(i)) {
+                                target = i;
+                                break;
+                        }
                 }
+
+                /*
+                 * Lets stop looking for an idle sibling when we reached
+                 * the domain that spans the current cpu and prev_cpu.
+                 */
+                if (cpumask_test_cpu(cpu, sched_domain_span(sd)) &&
+                    cpumask_test_cpu(prev_cpu, sched_domain_span(sd)))
+                        break;
         }
 
         return target;
@@ -1445,7 +1433,8 @@ select_idle_sibling(struct task_struct *p, struct sched_domain *sd, int target)
  *
  * preempt must be disabled.
  */
-static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flags)
+static int
+select_task_rq_fair(struct rq *rq, struct task_struct *p, int sd_flag, int wake_flags)
 {
         struct sched_domain *tmp, *affine_sd = NULL, *sd = NULL;
         int cpu = smp_processor_id();
@@ -1456,8 +1445,7 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag
         int sync = wake_flags & WF_SYNC;
 
         if (sd_flag & SD_BALANCE_WAKE) {
-                if (sched_feat(AFFINE_WAKEUPS) &&
-                    cpumask_test_cpu(cpu, &p->cpus_allowed))
+                if (cpumask_test_cpu(cpu, &p->cpus_allowed))
                         want_affine = 1;
                 new_cpu = prev_cpu;
         }
@@ -1491,34 +1479,13 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag
                 }
 
                 /*
-                 * While iterating the domains looking for a spanning
-                 * WAKE_AFFINE domain, adjust the affine target to any idle cpu
-                 * in cache sharing domains along the way.
+                 * If both cpu and prev_cpu are part of this domain,
+                 * cpu is a valid SD_WAKE_AFFINE target.
                  */
-                if (want_affine) {
-                        int target = -1;
-
-                        /*
-                         * If both cpu and prev_cpu are part of this domain,
-                         * cpu is a valid SD_WAKE_AFFINE target.
-                         */
-                        if (cpumask_test_cpu(prev_cpu, sched_domain_span(tmp)))
-                                target = cpu;
-
-                        /*
-                         * If there's an idle sibling in this domain, make that
-                         * the wake_affine target instead of the current cpu.
-                         */
-                        if (tmp->flags & SD_SHARE_PKG_RESOURCES)
-                                target = select_idle_sibling(p, tmp, target);
-
-                        if (target >= 0) {
-                                if (tmp->flags & SD_WAKE_AFFINE) {
-                                        affine_sd = tmp;
-                                        want_affine = 0;
-                                }
-                                cpu = target;
-                        }
+                if (want_affine && (tmp->flags & SD_WAKE_AFFINE) &&
+                    cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) {
+                        affine_sd = tmp;
+                        want_affine = 0;
                 }
 
                 if (!want_sd && !want_affine)
@@ -1531,22 +1498,29 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag
                         sd = tmp;
         }
 
+#ifdef CONFIG_FAIR_GROUP_SCHED
         if (sched_feat(LB_SHARES_UPDATE)) {
                 /*
                  * Pick the largest domain to update shares over
                  */
                 tmp = sd;
-                if (affine_sd && (!tmp ||
-                                  cpumask_weight(sched_domain_span(affine_sd)) >
-                                  cpumask_weight(sched_domain_span(sd))))
+                if (affine_sd && (!tmp || affine_sd->span_weight > sd->span_weight))
                         tmp = affine_sd;
 
-                if (tmp)
+                if (tmp) {
+                        raw_spin_unlock(&rq->lock);
                         update_shares(tmp);
+                        raw_spin_lock(&rq->lock);
+                }
         }
+#endif
 
-        if (affine_sd && wake_affine(affine_sd, p, sync))
-                return cpu;
+        if (affine_sd) {
+                if (cpu == prev_cpu || wake_affine(affine_sd, p, sync))
+                        return select_idle_sibling(p, cpu);
+                else
+                        return select_idle_sibling(p, prev_cpu);
+        }
 
         while (sd) {
                 int load_idx = sd->forkexec_idx;
@@ -1576,10 +1550,10 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag
 
                 /* Now try balancing at a lower domain level of new_cpu */
                 cpu = new_cpu;
-                weight = cpumask_weight(sched_domain_span(sd));
+                weight = sd->span_weight;
                 sd = NULL;
                 for_each_domain(cpu, tmp) {
-                        if (weight <= cpumask_weight(sched_domain_span(tmp)))
+                        if (weight <= tmp->span_weight)
                                 break;
                         if (tmp->flags & sd_flag)
                                 sd = tmp;
@@ -1591,63 +1565,26 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag
 }
 #endif /* CONFIG_SMP */
 
-/*
- * Adaptive granularity
- *
- * se->avg_wakeup gives the average time a task runs until it does a wakeup,
- * with the limit of wakeup_gran -- when it never does a wakeup.
- *
- * So the smaller avg_wakeup is the faster we want this task to preempt,
- * but we don't want to treat the preemptee unfairly and therefore allow it
- * to run for at least the amount of time we'd like to run.
- *
- * NOTE: we use 2*avg_wakeup to increase the probability of actually doing one
- *
- * NOTE: we use *nr_running to scale with load, this nicely matches the
- *       degrading latency on load.
- */
-static unsigned long
-adaptive_gran(struct sched_entity *curr, struct sched_entity *se)
-{
-        u64 this_run = curr->sum_exec_runtime - curr->prev_sum_exec_runtime;
-        u64 expected_wakeup = 2*se->avg_wakeup * cfs_rq_of(se)->nr_running;
-        u64 gran = 0;
-
-        if (this_run < expected_wakeup)
-                gran = expected_wakeup - this_run;
-
-        return min_t(s64, gran, sysctl_sched_wakeup_granularity);
-}
-
 static unsigned long
 wakeup_gran(struct sched_entity *curr, struct sched_entity *se)
 {
         unsigned long gran = sysctl_sched_wakeup_granularity;
 
-        if (cfs_rq_of(curr)->curr && sched_feat(ADAPTIVE_GRAN))
-                gran = adaptive_gran(curr, se);
-
         /*
          * Since its curr running now, convert the gran from real-time
          * to virtual-time in his units.
+         *
+         * By using 'se' instead of 'curr' we penalize light tasks, so
+         * they get preempted easier. That is, if 'se' < 'curr' then
+         * the resulting gran will be larger, therefore penalizing the
+         * lighter, if otoh 'se' > 'curr' then the resulting gran will
+         * be smaller, again penalizing the lighter task.
+         *
+         * This is especially important for buddies when the leftmost
+         * task is higher priority than the buddy.
          */
-        if (sched_feat(ASYM_GRAN)) {
-                /*
-                 * By using 'se' instead of 'curr' we penalize light tasks, so
-                 * they get preempted easier. That is, if 'se' < 'curr' then
-                 * the resulting gran will be larger, therefore penalizing the
-                 * lighter, if otoh 'se' > 'curr' then the resulting gran will
-                 * be smaller, again penalizing the lighter task.
-                 *
-                 * This is especially important for buddies when the leftmost
-                 * task is higher priority than the buddy.
-                 */
-                if (unlikely(se->load.weight != NICE_0_LOAD))
-                        gran = calc_delta_fair(gran, se);
-        } else {
-                if (unlikely(curr->load.weight != NICE_0_LOAD))
-                        gran = calc_delta_fair(gran, curr);
-        }
+        if (unlikely(se->load.weight != NICE_0_LOAD))
+                gran = calc_delta_fair(gran, se);
 
         return gran;
 }
@@ -1705,7 +1642,6 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
         struct task_struct *curr = rq->curr;
         struct sched_entity *se = &curr->se, *pse = &p->se;
         struct cfs_rq *cfs_rq = task_cfs_rq(curr);
-        int sync = wake_flags & WF_SYNC;
         int scale = cfs_rq->nr_running >= sched_nr_latency;
 
         if (unlikely(rt_prio(p->prio)))
@@ -1738,14 +1674,6 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
         if (unlikely(curr->policy == SCHED_IDLE))
                 goto preempt;
 
-        if (sched_feat(WAKEUP_SYNC) && sync)
-                goto preempt;
-
-        if (sched_feat(WAKEUP_OVERLAP) &&
-                        se->avg_overlap < sysctl_sched_migration_cost &&
-                        pse->avg_overlap < sysctl_sched_migration_cost)
-                goto preempt;
-
         if (!sched_feat(WAKEUP_PREEMPT))
                 return;
 
@@ -1844,13 +1772,13 @@ int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu,
          * 3) are cache-hot on their current CPU.
          */
         if (!cpumask_test_cpu(this_cpu, &p->cpus_allowed)) {
-                schedstat_inc(p, se.nr_failed_migrations_affine);
+                schedstat_inc(p, se.statistics.nr_failed_migrations_affine);
                 return 0;
         }
         *all_pinned = 0;
 
         if (task_running(rq, p)) {
-                schedstat_inc(p, se.nr_failed_migrations_running);
+                schedstat_inc(p, se.statistics.nr_failed_migrations_running);
                 return 0;
         }
 
@@ -1866,14 +1794,14 @@ int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu,
 #ifdef CONFIG_SCHEDSTATS
                 if (tsk_cache_hot) {
                         schedstat_inc(sd, lb_hot_gained[idle]);
-                        schedstat_inc(p, se.nr_forced_migrations);
+                        schedstat_inc(p, se.statistics.nr_forced_migrations);
                 }
 #endif
                 return 1;
         }
 
         if (tsk_cache_hot) {
-                schedstat_inc(p, se.nr_failed_migrations_hot);
+                schedstat_inc(p, se.statistics.nr_failed_migrations_hot);
                 return 0;
         }
         return 1;
@@ -2311,7 +2239,7 @@ unsigned long __weak arch_scale_freq_power(struct sched_domain *sd, int cpu)
 
 unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu)
 {
-        unsigned long weight = cpumask_weight(sched_domain_span(sd));
+        unsigned long weight = sd->span_weight;
         unsigned long smt_gain = sd->smt_gain;
 
         smt_gain /= weight;
@@ -2344,7 +2272,7 @@ unsigned long scale_rt_power(int cpu)
 
 static void update_cpu_power(struct sched_domain *sd, int cpu)
 {
-        unsigned long weight = cpumask_weight(sched_domain_span(sd));
+        unsigned long weight = sd->span_weight;
         unsigned long power = SCHED_LOAD_SCALE;
         struct sched_group *sdg = sd->groups;
 
@@ -2870,6 +2798,8 @@ static int need_active_balance(struct sched_domain *sd, int sd_idle, int idle)
         return unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2);
 }
 
+static int active_load_balance_cpu_stop(void *data);
+
 /*
  * Check this_cpu to ensure it is balanced within domain. Attempt to move
  * tasks if there is an imbalance.
@@ -2959,8 +2889,9 @@ redo:
                 if (need_active_balance(sd, sd_idle, idle)) {
                         raw_spin_lock_irqsave(&busiest->lock, flags);
 
-                        /* don't kick the migration_thread, if the curr
-                         * task on busiest cpu can't be moved to this_cpu
+                        /* don't kick the active_load_balance_cpu_stop,
+                         * if the curr task on busiest cpu can't be
+                         * moved to this_cpu
                          */
                         if (!cpumask_test_cpu(this_cpu,
                                               &busiest->curr->cpus_allowed)) {
@@ -2970,14 +2901,22 @@ redo:
                                 goto out_one_pinned;
                         }
 
+                        /*
+                         * ->active_balance synchronizes accesses to
+                         * ->active_balance_work.  Once set, it's cleared
+                         * only after active load balance is finished.
+                         */
                         if (!busiest->active_balance) {
                                 busiest->active_balance = 1;
                                 busiest->push_cpu = this_cpu;
                                 active_balance = 1;
                         }
                         raw_spin_unlock_irqrestore(&busiest->lock, flags);
+
                         if (active_balance)
-                                wake_up_process(busiest->migration_thread);
+                                stop_one_cpu_nowait(cpu_of(busiest),
+                                        active_load_balance_cpu_stop, busiest,
+                                        &busiest->active_balance_work);
 
                         /*
                          * We've kicked active balancing, reset the failure
@@ -3084,24 +3023,29 @@ static void idle_balance(int this_cpu, struct rq *this_rq)
 }
 
 /*
- * active_load_balance is run by migration threads. It pushes running tasks
- * off the busiest CPU onto idle CPUs. It requires at least 1 task to be
- * running on each physical CPU where possible, and avoids physical /
- * logical imbalances.
- *
- * Called with busiest_rq locked.
+ * active_load_balance_cpu_stop is run by cpu stopper. It pushes
+ * running tasks off the busiest CPU onto idle CPUs. It requires at
+ * least 1 task to be running on each physical CPU where possible, and
+ * avoids physical / logical imbalances.
  */
-static void active_load_balance(struct rq *busiest_rq, int busiest_cpu)
+static int active_load_balance_cpu_stop(void *data)
 {
+        struct rq *busiest_rq = data;
+        int busiest_cpu = cpu_of(busiest_rq);
         int target_cpu = busiest_rq->push_cpu;
+        struct rq *target_rq = cpu_rq(target_cpu);
         struct sched_domain *sd;
-        struct rq *target_rq;
+
+        raw_spin_lock_irq(&busiest_rq->lock);
+
+        /* make sure the requested cpu hasn't gone down in the meantime */
+        if (unlikely(busiest_cpu != smp_processor_id() ||
+                     !busiest_rq->active_balance))
+                goto out_unlock;
 
         /* Is there any task to move? */
         if (busiest_rq->nr_running <= 1)
-                return;
-
-        target_rq = cpu_rq(target_cpu);
+                goto out_unlock;
 
         /*
          * This condition is "impossible", if it occurs
@@ -3112,8 +3056,6 @@ static void active_load_balance(struct rq *busiest_rq, int busiest_cpu)
 
         /* move a task from busiest_rq to target_rq */
         double_lock_balance(busiest_rq, target_rq);
-        update_rq_clock(busiest_rq);
-        update_rq_clock(target_rq);
 
         /* Search for an sd spanning us and the target CPU. */
         for_each_domain(target_cpu, sd) {
@@ -3132,6 +3074,10 @@ static void active_load_balance(struct rq *busiest_rq, int busiest_cpu)
                         schedstat_inc(sd, alb_failed);
         }
         double_unlock_balance(busiest_rq, target_rq);
+out_unlock:
+        busiest_rq->active_balance = 0;
+        raw_spin_unlock_irq(&busiest_rq->lock);
+        return 0;
 }
 
 #ifdef CONFIG_NO_HZ