Messages in this thread Patch in this message |  | | From | Wanpeng Li <> | Subject | [PATCH v3] sched/deadline: do not try to push tasks if pinned task switches to dl | Date | Wed, 22 Oct 2014 08:36:43 +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 has had several dl tasks before they have already been considered as candidates to be pushed (or pulled). This patch implements 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 <wanpeng.li@linux.intel.com> --- v2 -> v3: * cleanup patch description * align && to p->nr_cpus_allowed 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..bd5e479 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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