diff --git a/include/linux/sched.h b/include/linux/sched.h
index 11d8e9a74effd57af24a7f8143b093da6d34f486..3625fcaf5d0f2e3f08ff928a567793aa8f890309 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -929,6 +929,9 @@ struct sched_entity {
u64 vruntime;
u64 prev_sum_exec_runtime;
+ u64 last_wakeup;
+ u64 avg_overlap;
+
#ifdef CONFIG_SCHEDSTATS
u64 wait_start;
u64 wait_max;
diff --git a/kernel/sched.c b/kernel/sched.c
index d1ad69b270ca7abc418871ce3160cc4bfbc04135..adbd475cfd2556e5c28591cb103de399111c64a6 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1855,10 +1855,11 @@ out_activate:
schedstat_inc(p, se.nr_wakeups_remote);
update_rq_clock(rq);
activate_task(rq, p, 1);
- check_preempt_curr(rq, p);
success = 1;
out_running:
+ check_preempt_curr(rq, p);
+
p->state = TASK_RUNNING;
#ifdef CONFIG_SMP
if (p->sched_class->task_wake_up)
@@ -1892,6 +1893,8 @@ static void __sched_fork(struct task_struct *p)
p->se.exec_start = 0;
p->se.sum_exec_runtime = 0;
p->se.prev_sum_exec_runtime = 0;
+ p->se.last_wakeup = 0;
+ p->se.avg_overlap = 0;
#ifdef CONFIG_SCHEDSTATS
p->se.wait_start = 0;
diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
index 4b5e24cf2f4a98387c849d8461b85a8a9c79aa55..ef358ba0768353cfd2e8bde743fa4901ab9141a7 100644
--- a/kernel/sched_debug.c
+++ b/kernel/sched_debug.c
@@ -288,6 +288,7 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
PN(se.exec_start);
PN(se.vruntime);
PN(se.sum_exec_runtime);
+ PN(se.avg_overlap);
nr_switches = p->nvcsw + p->nivcsw;
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index b5a357396b491d6326d507e1d814ebf535f05efe..87c9d3a2aafa405757e4776f4319e7ca7a346f31 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -556,6 +556,21 @@ 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 +581,7 @@ 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);
@@ -981,12 +997,15 @@ static inline int wake_idle(int cpu, struct task_struct *p)
#ifdef CONFIG_SMP
+static const struct sched_class fair_sched_class;
+
static int
-wake_affine(struct rq *rq, struct sched_domain *this_sd, struct task_struct *p,
- int prev_cpu, int this_cpu, int sync, int idx,
- unsigned long load, unsigned long this_load,
+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)
{
+ struct task_struct *curr = this_rq->curr;
unsigned long tl = this_load;
unsigned long tl_per_task;
@@ -994,10 +1013,15 @@ wake_affine(struct rq *rq, struct sched_domain *this_sd, struct task_struct *p,
return 0;
/*
- * Attract cache-cold tasks on sync wakeups:
+ * If the currently running task will sleep within
+ * a reasonable amount of time then attract this newly
+ * woken task:
*/
- if (sync && !task_hot(p, rq->clock, this_sd))
- return 1;
+ 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);
@@ -1030,18 +1054,16 @@ 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;
- struct rq *rq;
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;
- if (prev_cpu == this_cpu)
- goto out;
-
/*
* 'this_sd' is the first domain that both
* this_cpu and prev_cpu are present in:
@@ -1069,11 +1091,12 @@ static int select_task_rq_fair(struct task_struct *p, int sync)
load = source_load(prev_cpu, idx);
this_load = target_load(this_cpu, idx);
- if (wake_affine(rq, this_sd, p, prev_cpu, this_cpu, sync, idx,
- load, this_load, imbalance)) {
- new_cpu = this_cpu;
+ 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
@@ -1083,8 +1106,7 @@ static int select_task_rq_fair(struct task_struct *p, int sync)
if (imbalance*this_load <= 100*load) {
schedstat_inc(this_sd, ttwu_move_balance);
schedstat_inc(p, se.nr_wakeups_passive);
- new_cpu = this_cpu;
- goto out;
+ return this_cpu;
}
}
@@ -1111,6 +1133,10 @@ 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;
/*