1 files changed, 63 insertions, 170 deletions

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index f2eb5b934715..09d19f77eb3a 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -1062,83 +1062,6 @@ static void yield_task_fair(struct rq *rq)
         se->vruntime = rightmost->vruntime + 1;
 }
 
-/*
- * wake_idle() will wake a task on an idle cpu if task->cpu is
- * not idle and an idle cpu is available.  The span of cpus to
- * search starts with cpus closest then further out as needed,
- * so we always favor a closer, idle cpu.
- * Domains may include CPUs that are not usable for migration,
- * hence we need to mask them out (rq->rd->online)
- *
- * Returns the CPU we should wake onto.
- */
-#if defined(ARCH_HAS_SCHED_WAKE_IDLE)
-
-#define cpu_rd_active(cpu, rq) cpumask_test_cpu(cpu, rq->rd->online)
-
-static int wake_idle(int cpu, struct task_struct *p)
-{
-        struct sched_domain *sd;
-        int i;
-        unsigned int chosen_wakeup_cpu;
-        int this_cpu;
-        struct rq *task_rq = task_rq(p);
-
-        /*
-         * At POWERSAVINGS_BALANCE_WAKEUP level, if both this_cpu and prev_cpu
-         * are idle and this is not a kernel thread and this task's affinity
-         * allows it to be moved to preferred cpu, then just move!
-         */
-
-        this_cpu = smp_processor_id();
-        chosen_wakeup_cpu =
-                cpu_rq(this_cpu)->rd->sched_mc_preferred_wakeup_cpu;
-
-        if (sched_mc_power_savings >= POWERSAVINGS_BALANCE_WAKEUP &&
-                idle_cpu(cpu) && idle_cpu(this_cpu) &&
-                p->mm && !(p->flags & PF_KTHREAD) &&
-                cpu_isset(chosen_wakeup_cpu, p->cpus_allowed))
-                return chosen_wakeup_cpu;
-
-        /*
-         * If it is idle, then it is the best cpu to run this task.
-         *
-         * This cpu is also the best, if it has more than one task already.
-         * Siblings must be also busy(in most cases) as they didn't already
-         * pickup the extra load from this cpu and hence we need not check
-         * sibling runqueue info. This will avoid the checks and cache miss
-         * penalities associated with that.
-         */
-        if (idle_cpu(cpu) || cpu_rq(cpu)->cfs.nr_running > 1)
-                return cpu;
-
-        for_each_domain(cpu, sd) {
-                if ((sd->flags & SD_WAKE_IDLE)
-                    || ((sd->flags & SD_WAKE_IDLE_FAR)
-                        && !task_hot(p, task_rq->clock, sd))) {
-                        for_each_cpu_and(i, sched_domain_span(sd),
-                                         &p->cpus_allowed) {
-                                if (cpu_rd_active(i, task_rq) && idle_cpu(i)) {
-                                        if (i != task_cpu(p)) {
-                                                schedstat_inc(p,
-                                                       se.nr_wakeups_idle);
-                                        }
-                                        return i;
-                                }
-                        }
-                } else {
-                        break;
-                }
-        }
-        return cpu;
-}
-#else /* !ARCH_HAS_SCHED_WAKE_IDLE*/
-static inline int wake_idle(int cpu, struct task_struct *p)
-{
-        return cpu;
-}
-#endif
-
 #ifdef CONFIG_SMP
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
@@ -1225,21 +1148,22 @@ static inline unsigned long effective_load(struct task_group *tg, int cpu,
 
 #endif
 
-static int
-wake_affine(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)
+static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
 {
-        struct task_struct *curr = this_rq->curr;
-        struct task_group *tg;
-        unsigned long tl = this_load;
+        struct task_struct *curr = current;
+        unsigned long this_load, load;
+        int idx, this_cpu, prev_cpu;
         unsigned long tl_per_task;
+        unsigned int imbalance;
+        struct task_group *tg;
         unsigned long weight;
         int balanced;
 
-        if (!(this_sd->flags & SD_WAKE_AFFINE) || !sched_feat(AFFINE_WAKEUPS))
-                return 0;
+        idx       = sd->wake_idx;
+        this_cpu  = smp_processor_id();
+        prev_cpu  = task_cpu(p);
+        load      = source_load(prev_cpu, idx);
+        this_load = target_load(this_cpu, idx);
 
         if (sync && (curr->se.avg_overlap > sysctl_sched_migration_cost ||
                         p->se.avg_overlap > sysctl_sched_migration_cost))
@@ -1254,24 +1178,26 @@ wake_affine(struct sched_domain *this_sd, struct rq *this_rq,
                 tg = task_group(current);
                 weight = current->se.load.weight;
 
-                tl += effective_load(tg, this_cpu, -weight, -weight);
+                this_load += effective_load(tg, this_cpu, -weight, -weight);
                 load += effective_load(tg, prev_cpu, 0, -weight);
         }
 
         tg = task_group(p);
         weight = p->se.load.weight;
 
+        imbalance = 100 + (sd->imbalance_pct - 100) / 2;
+
         /*
          * In low-load situations, where prev_cpu is idle and this_cpu is idle
-         * due to the sync cause above having dropped tl to 0, we'll always have
-         * an imbalance, but there's really nothing you can do about that, so
-         * that's good too.
+         * due to the sync cause above having dropped this_load to 0, we'll
+         * always have an imbalance, but there's really nothing you can do
+         * about that, so that's good too.
          *
          * Otherwise check if either cpus are near enough in load to allow this
          * task to be woken on this_cpu.
          */
-        balanced = !tl ||
-                100*(tl + effective_load(tg, this_cpu, weight, weight)) <=
+        balanced = !this_load ||
+                100*(this_load + effective_load(tg, this_cpu, weight, weight)) <=
                 imbalance*(load + effective_load(tg, prev_cpu, 0, weight));
 
         /*
@@ -1285,14 +1211,15 @@ wake_affine(struct sched_domain *this_sd, struct rq *this_rq,
         schedstat_inc(p, se.nr_wakeups_affine_attempts);
         tl_per_task = cpu_avg_load_per_task(this_cpu);
 
-        if (balanced || (tl <= load && tl + target_load(prev_cpu, idx) <=
-                        tl_per_task)) {
+        if (balanced ||
+            (this_load <= load &&
+             this_load + target_load(prev_cpu, idx) <= tl_per_task)) {
                 /*
                  * 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(sd, ttwu_move_affine);
                 schedstat_inc(p, se.nr_wakeups_affine);
 
                 return 1;
@@ -1300,72 +1227,6 @@ wake_affine(struct sched_domain *this_sd, struct rq *this_rq,
         return 0;
 }
 
-static int sched_balance_self(int cpu, int flag);
-
-static int select_task_rq_fair(struct task_struct *p, int flag, int sync)
-{
-        struct sched_domain *sd, *this_sd = NULL;
-        int prev_cpu, this_cpu, new_cpu;
-        unsigned long load, this_load;
-        struct rq *this_rq;
-        unsigned int imbalance;
-        int idx;
-
-        prev_cpu        = task_cpu(p);
-        this_cpu        = smp_processor_id();
-        this_rq         = cpu_rq(this_cpu);
-        new_cpu         = prev_cpu;
-
-        if (flag != SD_BALANCE_WAKE)
-                return sched_balance_self(this_cpu, flag);
-
-        /*
-         * 'this_sd' is the first domain that both
-         * this_cpu and prev_cpu are present in:
-         */
-        for_each_domain(this_cpu, sd) {
-                if (cpumask_test_cpu(prev_cpu, sched_domain_span(sd))) {
-                        this_sd = sd;
-                        break;
-                }
-        }
-
-        if (unlikely(!cpumask_test_cpu(this_cpu, &p->cpus_allowed)))
-                goto out;
-
-        /*
-         * Check for affine wakeup and passive balancing possibilities.
-         */
-        if (!this_sd)
-                goto out;
-
-        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(this_sd, this_rq, p, prev_cpu, this_cpu, sync, idx,
-                                     load, this_load, imbalance))
-                return this_cpu;
-
-        /*
-         * 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;
-                }
-        }
-
-out:
-        return wake_idle(new_cpu, p);
-}
-
 /*
  * find_idlest_group finds and returns the least busy CPU group within the
  * domain.
@@ -1455,10 +1316,20 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
  *
  * preempt must be disabled.
  */
-static int sched_balance_self(int cpu, int flag)
+static int select_task_rq_fair(struct task_struct *p, int flag, int sync)
 {
         struct task_struct *t = current;
         struct sched_domain *tmp, *sd = NULL;
+        int cpu = smp_processor_id();
+        int prev_cpu = task_cpu(p);
+        int new_cpu = cpu;
+        int want_affine = 0;
+
+        if (flag & SD_BALANCE_WAKE) {
+                if (sched_feat(AFFINE_WAKEUPS))
+                        want_affine = 1;
+                new_cpu = prev_cpu;
+        }
 
         for_each_domain(cpu, tmp) {
                 /*
@@ -1466,16 +1337,38 @@ static int sched_balance_self(int cpu, int flag)
                  */
                 if (tmp->flags & SD_POWERSAVINGS_BALANCE)
                         break;
-                if (tmp->flags & flag)
-                        sd = tmp;
-        }
 
-        if (sd)
-                update_shares(sd);
+                switch (flag) {
+                case SD_BALANCE_WAKE:
+                        if (!sched_feat(LB_WAKEUP_UPDATE))
+                                break;
+                case SD_BALANCE_FORK:
+                case SD_BALANCE_EXEC:
+                        if (root_task_group_empty())
+                                break;
+                        update_shares(tmp);
+                default:
+                        break;
+                }
+
+                if (want_affine && (tmp->flags & SD_WAKE_AFFINE) &&
+                    cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) {
+
+                        if (wake_affine(tmp, p, sync))
+                                return cpu;
+
+                        want_affine = 0;
+                }
+
+                if (!(tmp->flags & flag))
+                        continue;
+
+                sd = tmp;
+        }
 
         while (sd) {
                 struct sched_group *group;
-                int new_cpu, weight;
+                int weight;
 
                 if (!(sd->flags & flag)) {
                         sd = sd->child;
@@ -1508,7 +1401,7 @@ static int sched_balance_self(int cpu, int flag)
                 /* while loop will break here if sd == NULL */
         }
 
-        return cpu;
+        return new_cpu;
 }
 #endif /* CONFIG_SMP */