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...@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 b8b9355..844da0f 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -1739,7 +1739,13 @@ 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);
}
@@ -1786,6 +1792,14 @@ 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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