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. 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/
