diff options
| -rw-r--r-- | include/linux/sched.h | 3 | ||||
| -rw-r--r-- | kernel/sched.c | 5 | ||||
| -rw-r--r-- | kernel/sched_debug.c | 1 | ||||
| -rw-r--r-- | kernel/sched_fair.c | 58 |
4 files changed, 50 insertions, 17 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 11d8e9a74ef..3625fcaf5d0 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 d1ad69b270c..adbd475cfd2 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 4b5e24cf2f4..ef358ba0768 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 b5a357396b4..87c9d3a2aaf 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; /* |