diff options
Diffstat (limited to 'kernel/sched_fair.c')
| -rw-r--r-- | kernel/sched_fair.c | 46 |
1 files changed, 35 insertions, 11 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index ee3771850aa..ce39282d9c0 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -354,7 +354,7 @@ __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr) delta_fair = calc_delta_fair(delta_exec, lw); delta_mine = calc_delta_mine(delta_exec, curr->load.weight, lw); - if (cfs_rq->sleeper_bonus > sysctl_sched_latency) { + if (cfs_rq->sleeper_bonus > sysctl_sched_min_granularity) { delta = min((u64)delta_mine, cfs_rq->sleeper_bonus); delta = min(delta, (unsigned long)( (long)sysctl_sched_runtime_limit - curr->wait_runtime)); @@ -489,6 +489,9 @@ update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se) { unsigned long delta_fair; + if (unlikely(!se->wait_start_fair)) + return; + delta_fair = (unsigned long)min((u64)(2*sysctl_sched_runtime_limit), (u64)(cfs_rq->fair_clock - se->wait_start_fair)); @@ -668,7 +671,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep) /* * Preempt the current task with a newly woken task if needed: */ -static void +static int __check_preempt_curr_fair(struct cfs_rq *cfs_rq, struct sched_entity *se, struct sched_entity *curr, unsigned long granularity) { @@ -679,8 +682,11 @@ __check_preempt_curr_fair(struct cfs_rq *cfs_rq, struct sched_entity *se, * preempt the current task unless the best task has * a larger than sched_granularity fairness advantage: */ - if (__delta > niced_granularity(curr, granularity)) + if (__delta > niced_granularity(curr, granularity)) { resched_task(rq_of(cfs_rq)->curr); + return 1; + } + return 0; } static inline void @@ -725,6 +731,7 @@ static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev) static void entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr) { + unsigned long gran, ideal_runtime, delta_exec; struct sched_entity *next; /* @@ -741,8 +748,22 @@ static void entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr) if (next == curr) return; - __check_preempt_curr_fair(cfs_rq, next, curr, - sched_granularity(cfs_rq)); + gran = sched_granularity(cfs_rq); + ideal_runtime = niced_granularity(curr, + max(sysctl_sched_latency / cfs_rq->nr_running, + (unsigned long)sysctl_sched_min_granularity)); + /* + * If we executed more than what the latency constraint suggests, + * reduce the rescheduling granularity. This way the total latency + * of how much a task is not scheduled converges to + * sysctl_sched_latency: + */ + delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime; + if (delta_exec > ideal_runtime) + gran = 0; + + if (__check_preempt_curr_fair(cfs_rq, next, curr, gran)) + curr->prev_sum_exec_runtime = curr->sum_exec_runtime; } /************************************************** @@ -1076,31 +1097,34 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr) static void task_new_fair(struct rq *rq, struct task_struct *p) { struct cfs_rq *cfs_rq = task_cfs_rq(p); - struct sched_entity *se = &p->se; + struct sched_entity *se = &p->se, *curr = cfs_rq_curr(cfs_rq); sched_info_queued(p); + update_curr(cfs_rq); update_stats_enqueue(cfs_rq, se); /* * Child runs first: we let it run before the parent * until it reschedules once. We set up the key so that * it will preempt the parent: */ - p->se.fair_key = current->se.fair_key - - niced_granularity(&rq->curr->se, sched_granularity(cfs_rq)) - 1; + se->fair_key = curr->fair_key - + niced_granularity(curr, sched_granularity(cfs_rq)) - 1; /* * The first wait is dominated by the child-runs-first logic, * so do not credit it with that waiting time yet: */ if (sysctl_sched_features & SCHED_FEAT_SKIP_INITIAL) - p->se.wait_start_fair = 0; + se->wait_start_fair = 0; /* * The statistical average of wait_runtime is about * -granularity/2, so initialize the task with that: */ - if (sysctl_sched_features & SCHED_FEAT_START_DEBIT) - p->se.wait_runtime = -(sched_granularity(cfs_rq) / 2); + if (sysctl_sched_features & SCHED_FEAT_START_DEBIT) { + se->wait_runtime = -(sched_granularity(cfs_rq) / 2); + schedstat_add(cfs_rq, wait_runtime, se->wait_runtime); + } __enqueue_entity(cfs_rq, se); } |