diff options
| -rw-r--r-- | kernel/sched_fair.c | 69 |
1 files changed, 49 insertions, 20 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 86a93376282..b01f8e77f2a 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: 5 msec * (1 + ilog(ncpus)), units: nanoseconds) + * (default: 10 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 = 5000000UL; +unsigned int sysctl_sched_wakeup_granularity = 10000000UL; const_debug unsigned int sysctl_sched_migration_cost = 500000UL; @@ -629,20 +629,16 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se) se->prev_sum_exec_runtime = se->sum_exec_runtime; } +static int +wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se); + static struct sched_entity * pick_next(struct cfs_rq *cfs_rq, struct sched_entity *se) { - s64 diff, gran; - if (!cfs_rq->next) return se; - diff = cfs_rq->next->vruntime - se->vruntime; - if (diff < 0) - return se; - - gran = calc_delta_fair(sysctl_sched_wakeup_granularity, &cfs_rq->load); - if (diff > gran) + if (wakeup_preempt_entity(cfs_rq->next, se) != 0) return se; return cfs_rq->next; @@ -1101,6 +1097,48 @@ out: } #endif /* CONFIG_SMP */ +static unsigned long wakeup_gran(struct sched_entity *se) +{ + unsigned long gran = sysctl_sched_wakeup_granularity; + + /* + * More easily preempt - nice tasks, while not making + * it harder for + nice tasks. + */ + if (unlikely(se->load.weight > NICE_0_LOAD)) + gran = calc_delta_fair(gran, &se->load); + + return gran; +} + +/* + * Should 'se' preempt 'curr'. + * + * |s1 + * |s2 + * |s3 + * g + * |<--->|c + * + * w(c, s1) = -1 + * w(c, s2) = 0 + * w(c, s3) = 1 + * + */ +static int +wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se) +{ + s64 gran, vdiff = curr->vruntime - se->vruntime; + + if (vdiff < 0) + return -1; + + gran = wakeup_gran(curr); + if (vdiff > gran) + return 1; + + return 0; +} /* * Preempt the current task with a newly woken task if needed: @@ -1110,7 +1148,6 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p) struct task_struct *curr = rq->curr; struct cfs_rq *cfs_rq = task_cfs_rq(curr); struct sched_entity *se = &curr->se, *pse = &p->se; - unsigned long gran; if (unlikely(rt_prio(p->prio))) { update_rq_clock(rq); @@ -1140,15 +1177,7 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p) pse = parent_entity(pse); } - gran = sysctl_sched_wakeup_granularity; - /* - * More easily preempt - nice tasks, while not making - * it harder for + nice tasks. - */ - if (unlikely(se->load.weight > NICE_0_LOAD)) - gran = calc_delta_fair(gran, &se->load); - - if (pse->vruntime + gran < se->vruntime) + if (wakeup_preempt_entity(se, pse) == 1) resched_task(curr); } |