On 21/04/15 00:02, Wanpeng Li wrote: > On Tue, Apr 21, 2015 at 06:59:02AM +0800, Wanpeng Li wrote: >> Hi Juri, >> On Mon, Apr 20, 2015 at 11:27:22AM +0100, Juri Lelli wrote: >>> Hi, >>> >>> On 06/04/2015 09:53, Wanpeng Li wrote: >>>> 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. >>>> >>> >>> Ok, I guess it can happen. Doesn't RT have the same problem? It seems that >>> it also has to deal with DL tasks slipping in, right? >> >> Yeah, I will send another patch to handle RT class in the v2 patchset. :) > > Oh, I just find I have already done them in patch 7/7. >
Oh, right! That one ended up in another bucket. Sorry about that. Best, - Juri > Regards, > Wanpeng Li > >> >> Regards, >> Wanpeng Li >> >>> >>> Thanks, >>> >>> - Juri >>> >>>> 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. >>>> > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
