From 2e09bf556fbe1a4cd8d837a3e6607de55f7cf4fd Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 15 Oct 2007 17:00:05 +0200 Subject: sched: wakeup granularity increase increase wakeup granularity - we were overscheduling a bit. Signed-off-by: Ingo Molnar Signed-off-by: Peter Zijlstra Signed-off-by: Mike Galbraith --- kernel/sched_fair.c | 27 +++++++++++---------------- 1 file changed, 11 insertions(+), 16 deletions(-) diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 45c7493d8ca8..a60b1dac598a 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -74,7 +74,7 @@ const_debug unsigned int sysctl_sched_batch_wakeup_granularity = 25000000UL; * and reduces their over-scheduling. Synchronous workloads will still * have immediate wakeup/sleep latencies. */ -const_debug unsigned int sysctl_sched_wakeup_granularity = 1000000UL; +const_debug unsigned int sysctl_sched_wakeup_granularity = 2000000UL; unsigned int sysctl_sched_runtime_limit __read_mostly; @@ -582,7 +582,7 @@ 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 -__check_preempt_curr_fair(struct cfs_rq *cfs_rq, struct sched_entity *curr) +check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr) { unsigned long ideal_runtime, delta_exec; @@ -646,8 +646,6 @@ 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) { - struct sched_entity *next; - /* * Dequeue and enqueue the task to update its * position within the tree: @@ -655,14 +653,8 @@ static void entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr) dequeue_entity(cfs_rq, curr, 0); enqueue_entity(cfs_rq, curr, 0); - /* - * Reschedule if another task tops the current one. - */ - next = __pick_next_entity(cfs_rq); - if (next == curr) - return; - - __check_preempt_curr_fair(cfs_rq, curr); + if (cfs_rq->nr_running > 1) + check_preempt_tick(cfs_rq, curr); } /************************************************** @@ -852,7 +844,7 @@ static void yield_task_fair(struct rq *rq, struct task_struct *p) /* * Preempt the current task with a newly woken task if needed: */ -static void check_preempt_curr_fair(struct rq *rq, struct task_struct *p) +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); @@ -863,9 +855,12 @@ static void check_preempt_curr_fair(struct rq *rq, struct task_struct *p) resched_task(curr); return; } + if (is_same_group(curr, p)) { + s64 delta = curr->se.vruntime - p->se.vruntime; - if (is_same_group(curr, p)) - __check_preempt_curr_fair(cfs_rq, &curr->se); + if (delta > (s64)sysctl_sched_wakeup_granularity) + resched_task(curr); + } } static struct task_struct *pick_next_task_fair(struct rq *rq) @@ -1095,7 +1090,7 @@ struct sched_class fair_sched_class __read_mostly = { .dequeue_task = dequeue_task_fair, .yield_task = yield_task_fair, - .check_preempt_curr = check_preempt_curr_fair, + .check_preempt_curr = check_preempt_wakeup, .pick_next_task = pick_next_task_fair, .put_prev_task = put_prev_task_fair, -- cgit v1.2.2