From 247460238414744119265d6aa92f4bf006b060aa Mon Sep 17 00:00:00 2001 From: Wanpeng Li Date: Fri, 10 Oct 2014 10:09:37 +0800 Subject: [PATCH v2] sched/deadline: do not try to push tasks if pinned task switches to dl As Kirill mentioned(https://lkml.org/lkml/2013/1/29/118): | If rq has already had 2 or more pushable tasks and we try to add a | pinned task then call of push_rt_task will just waste a time. Just switched pinned task is not able to be pushed. If the rq had had several dl tasks before they have already been considered as candidates to be pushed (or pulled). This patch done the same behavior as rt class which introduced by commit 10447917551e ("sched/rt: Do not try to push tasks if pinned task switches to RT"). Signed-off-by: Wanpeng Li --- v1 -> v2: * use 12 or more chars for the git commit ID kernel/sched/deadline.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index abfaf3d..cf7c9b6 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1603,7 +1603,8 @@ static void switched_to_dl(struct rq *rq, struct task_struct *p) if (task_on_rq_queued(p) && rq->curr != p) { #ifdef CONFIG_SMP - if (rq->dl.overloaded && push_dl_task(rq) && rq != task_rq(p)) + if (p->nr_cpus_allowed > 1 && rq->dl.overloaded + && push_dl_task(rq) && rq != task_rq(p)) /* Only reschedule if pushing failed */ check_resched = 0; #endif /* CONFIG_SMP */ -- 1.9.1