pull_rt_task() can drop (and re-acquire) rq->lock, this means a dl or stop task
can slip in, in which case need to reschedule. This patch add the reschedule
when the scenario occurs.
Signed-off-by: Wanpeng Li <wanpeng...@linux.intel.com>
---
kernel/sched/rt.c | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 575da76..cc973e8 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -2136,7 +2136,14 @@ static void switched_from_rt(struct rq *rq, struct
task_struct *p)
if (!task_on_rq_queued(p) || rq->rt.rt_nr_running)
return;
- if (pull_rt_task(rq))
+ /*
+ * pull_rt_task() can drop (and re-acquire) rq->lock; this
+ * means a dl or stop task can slip in, in which case we need
+ * to reschedule.
+ */
+ if (pull_rt_task(rq) ||
+ (unlikely((rq->stop && task_on_rq_queued(rq->stop)) ||
+ rq->dl.dl_nr_running)))
resched_curr(rq);
}
@@ -2197,6 +2204,16 @@ prio_changed_rt(struct rq *rq, struct task_struct *p,
int oldprio)
*/
if (oldprio < p->prio)
pull_rt_task(rq);
+
+ /*
+ * pull_rt_task() can drop (and re-acquire) rq->lock; this
+ * means a dl or stop task can slip in, in which case we need
+ * to reschedule.
+ */
+ if (unlikely((rq->stop && task_on_rq_queued(rq->stop)) ||
+ rq->dl.dl_nr_running))
+ resched_curr(rq);
+
/*
* If there's a higher priority task waiting to run
* then reschedule. Note, the above pull_rt_task
--
1.9.1
--
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