1 files changed, 118 insertions, 87 deletions

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index f2cc59080efa..86a93376282c 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -73,13 +73,13 @@ unsigned int sysctl_sched_batch_wakeup_granularity = 10000000UL;
 
 /*
  * SCHED_OTHER wake-up granularity.
- * (default: 10 msec * (1 + ilog(ncpus)), units: nanoseconds)
+ * (default: 5 msec * (1 + ilog(ncpus)), units: nanoseconds)
  *
  * This option delays the preemption effects of decoupled workloads
  * and reduces their over-scheduling. Synchronous workloads will still
  * have immediate wakeup/sleep latencies.
  */
-unsigned int sysctl_sched_wakeup_granularity = 10000000UL;
+unsigned int sysctl_sched_wakeup_granularity = 5000000UL;
 
 const_debug unsigned int sysctl_sched_migration_cost = 500000UL;
 
@@ -302,11 +302,6 @@ static u64 __sched_vslice(unsigned long rq_weight, unsigned long nr_running)
         return vslice;
 }
 
-static u64 sched_vslice(struct cfs_rq *cfs_rq)
-{
-        return __sched_vslice(cfs_rq->load.weight, cfs_rq->nr_running);
-}
-
 static u64 sched_vslice_add(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
         return __sched_vslice(cfs_rq->load.weight + se->load.weight,
@@ -504,15 +499,6 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
         } else
                 vruntime = cfs_rq->min_vruntime;
 
-        if (sched_feat(TREE_AVG)) {
-                struct sched_entity *last = __pick_last_entity(cfs_rq);
-                if (last) {
-                        vruntime += last->vruntime;
-                        vruntime >>= 1;
-                }
-        } else if (sched_feat(APPROX_AVG) && cfs_rq->nr_running)
-                vruntime += sched_vslice(cfs_rq)/2;
-
         /*
          * The 'current' period is already promised to the current tasks,
          * however the extra weight of the new task will slow them down a
@@ -556,6 +542,21 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup)
         account_entity_enqueue(cfs_rq, se);
 }
 
+static void update_avg(u64 *avg, u64 sample)
+{
+        s64 diff = sample - *avg;
+        *avg += diff >> 3;
+}
+
+static void update_avg_stats(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+        if (!se->last_wakeup)
+                return;
+
+        update_avg(&se->avg_overlap, se->sum_exec_runtime - se->last_wakeup);
+        se->last_wakeup = 0;
+}
+
 static void
 dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
 {
@@ -566,6 +567,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
 
         update_stats_dequeue(cfs_rq, se);
         if (sleep) {
+                update_avg_stats(cfs_rq, se);
 #ifdef CONFIG_SCHEDSTATS
                 if (entity_is_task(se)) {
                         struct task_struct *tsk = task_of(se);
@@ -980,96 +982,121 @@ static inline int wake_idle(int cpu, struct task_struct *p)
 #endif
 
 #ifdef CONFIG_SMP
-static int select_task_rq_fair(struct task_struct *p, int sync)
+
+static const struct sched_class fair_sched_class;
+
+static int
+wake_affine(struct rq *rq, struct sched_domain *this_sd, struct rq *this_rq,
+            struct task_struct *p, int prev_cpu, int this_cpu, int sync,
+            int idx, unsigned long load, unsigned long this_load,
+            unsigned int imbalance)
 {
-        int cpu, this_cpu;
-        struct rq *rq;
-        struct sched_domain *sd, *this_sd = NULL;
-        int new_cpu;
+        struct task_struct *curr = this_rq->curr;
+        unsigned long tl = this_load;
+        unsigned long tl_per_task;
+
+        if (!(this_sd->flags & SD_WAKE_AFFINE))
+                return 0;
+
+        /*
+         * If the currently running task will sleep within
+         * a reasonable amount of time then attract this newly
+         * woken task:
+         */
+        if (sync && curr->sched_class == &fair_sched_class) {
+                if (curr->se.avg_overlap < sysctl_sched_migration_cost &&
+                                p->se.avg_overlap < sysctl_sched_migration_cost)
+                        return 1;
+        }
+
+        schedstat_inc(p, se.nr_wakeups_affine_attempts);
+        tl_per_task = cpu_avg_load_per_task(this_cpu);
+
+        /*
+         * If sync wakeup then subtract the (maximum possible)
+         * effect of the currently running task from the load
+         * of the current CPU:
+         */
+        if (sync)
+                tl -= current->se.load.weight;
+
+        if ((tl <= load && tl + target_load(prev_cpu, idx) <= tl_per_task) ||
+                        100*(tl + p->se.load.weight) <= imbalance*load) {
+                /*
+                 * This domain has SD_WAKE_AFFINE and
+                 * p is cache cold in this domain, and
+                 * there is no bad imbalance.
+                 */
+                schedstat_inc(this_sd, ttwu_move_affine);
+                schedstat_inc(p, se.nr_wakeups_affine);
 
-        cpu      = task_cpu(p);
-        rq       = task_rq(p);
-        this_cpu = smp_processor_id();
-        new_cpu  = cpu;
+                return 1;
+        }
+        return 0;
+}
 
-        if (cpu == this_cpu)
-                goto out_set_cpu;
+static int select_task_rq_fair(struct task_struct *p, int sync)
+{
+        struct sched_domain *sd, *this_sd = NULL;
+        int prev_cpu, this_cpu, new_cpu;
+        unsigned long load, this_load;
+        struct rq *rq, *this_rq;
+        unsigned int imbalance;
+        int idx;
+
+        prev_cpu        = task_cpu(p);
+        rq              = task_rq(p);
+        this_cpu        = smp_processor_id();
+        this_rq         = cpu_rq(this_cpu);
+        new_cpu         = prev_cpu;
 
+        /*
+         * 'this_sd' is the first domain that both
+         * this_cpu and prev_cpu are present in:
+         */
         for_each_domain(this_cpu, sd) {
-                if (cpu_isset(cpu, sd->span)) {
+                if (cpu_isset(prev_cpu, sd->span)) {
                         this_sd = sd;
                         break;
                 }
         }
 
         if (unlikely(!cpu_isset(this_cpu, p->cpus_allowed)))
-                goto out_set_cpu;
+                goto out;
 
         /*
          * Check for affine wakeup and passive balancing possibilities.
          */
-        if (this_sd) {
-                int idx = this_sd->wake_idx;
-                unsigned int imbalance;
-                unsigned long load, this_load;
-
-                imbalance = 100 + (this_sd->imbalance_pct - 100) / 2;
-
-                load = source_load(cpu, idx);
-                this_load = target_load(this_cpu, idx);
-
-                new_cpu = this_cpu; /* Wake to this CPU if we can */
-
-                if (this_sd->flags & SD_WAKE_AFFINE) {
-                        unsigned long tl = this_load;
-                        unsigned long tl_per_task;
-
-                        /*
-                         * Attract cache-cold tasks on sync wakeups:
-                         */
-                        if (sync && !task_hot(p, rq->clock, this_sd))
-                                goto out_set_cpu;
-
-                        schedstat_inc(p, se.nr_wakeups_affine_attempts);
-                        tl_per_task = cpu_avg_load_per_task(this_cpu);
-
-                        /*
-                         * If sync wakeup then subtract the (maximum possible)
-                         * effect of the currently running task from the load
-                         * of the current CPU:
-                         */
-                        if (sync)
-                                tl -= current->se.load.weight;
-
-                        if ((tl <= load &&
-                                tl + target_load(cpu, idx) <= tl_per_task) ||
-                               100*(tl + p->se.load.weight) <= imbalance*load) {
-                                /*
-                                 * This domain has SD_WAKE_AFFINE and
-                                 * p is cache cold in this domain, and
-                                 * there is no bad imbalance.
-                                 */
-                                schedstat_inc(this_sd, ttwu_move_affine);
-                                schedstat_inc(p, se.nr_wakeups_affine);
-                                goto out_set_cpu;
-                        }
-                }
+        if (!this_sd)
+                goto out;
 
-                /*
-                 * Start passive balancing when half the imbalance_pct
-                 * limit is reached.
-                 */
-                if (this_sd->flags & SD_WAKE_BALANCE) {
-                        if (imbalance*this_load <= 100*load) {
-                                schedstat_inc(this_sd, ttwu_move_balance);
-                                schedstat_inc(p, se.nr_wakeups_passive);
-                                goto out_set_cpu;
-                        }
+        idx = this_sd->wake_idx;
+
+        imbalance = 100 + (this_sd->imbalance_pct - 100) / 2;
+
+        load = source_load(prev_cpu, idx);
+        this_load = target_load(this_cpu, idx);
+
+        if (wake_affine(rq, this_sd, this_rq, p, prev_cpu, this_cpu, sync, idx,
+                                     load, this_load, imbalance))
+                return this_cpu;
+
+        if (prev_cpu == this_cpu)
+                goto out;
+
+        /*
+         * Start passive balancing when half the imbalance_pct
+         * limit is reached.
+         */
+        if (this_sd->flags & SD_WAKE_BALANCE) {
+                if (imbalance*this_load <= 100*load) {
+                        schedstat_inc(this_sd, ttwu_move_balance);
+                        schedstat_inc(p, se.nr_wakeups_passive);
+                        return this_cpu;
                 }
         }
 
-        new_cpu = cpu; /* Could not wake to this_cpu. Wake to cpu instead */
-out_set_cpu:
+out:
         return wake_idle(new_cpu, p);
 }
 #endif /* CONFIG_SMP */
@@ -1092,6 +1119,10 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p)
                 return;
         }
 
+        se->last_wakeup = se->sum_exec_runtime;
+        if (unlikely(se == pse))
+                return;
+
         cfs_rq_of(pse)->next = pse;
 
         /*