Messages in this thread Patch in this message | | | From | Wanpeng Li <> | Subject | [PATCH] sched/deadline: do not try to push tasks if pinned task switches to dl | Date | Fri, 10 Oct 2014 10:43:17 +0800 |
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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 does the same behavior as rt class which introduced by commit 104479 (sched/rt: Do not try to push tasks if pinned task switches to RT).
Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com> --- 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
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