Messages in this thread Patch in this message | | | From | Wanpeng Li <> | Subject | [PATCH v2 4/7] sched/deadline: reschedule if stop task slip in after pull operations | Date | Wed, 13 May 2015 14:01:04 +0800 |
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pull_dl_task can drop (and re-acquire) rq->lock, this means a stop task can slip in, in which case we need to reschedule. This patch add the reschedule when the scenario occurs.
Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com> --- kernel/sched/deadline.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index e49b1e6..7d4c4fc 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1750,7 +1750,13 @@ static void switched_from_dl(struct rq *rq, struct task_struct *p) if (!task_on_rq_queued(p) || rq->dl.dl_nr_running) return; - if (pull_dl_task(rq)) + /* + * pull_dl_task() can drop (and re-acquire) rq->lock; this + * means a stop task can slip in, in which case we need to + * reschedule. + */ + if (pull_dl_task(rq) || + (rq->stop && task_on_rq_queued(rq->stop))) resched_curr(rq); } @@ -1797,6 +1803,14 @@ static void prio_changed_dl(struct rq *rq, struct task_struct *p, pull_dl_task(rq); /* + * pull_dl_task() can drop (and re-acquire) rq->lock; this + * means a stop task can slip in, in which case we need to + * reschedule. + */ + if (rq->stop && task_on_rq_queued(rq->stop)) + resched_curr(rq); + + /* * If we now have a earlier deadline task than p, * then reschedule, provided p is still on this * runqueue. -- 1.9.1
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