Messages in this thread Patch in this message | | | Date | Thu, 5 Mar 2015 09:27:04 +0800 | From | Wanpeng Li <> | Subject | Re: [PATCH RESEND] sched/deadline: fix pull if dl task who's prio changed is not on queue |
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On Tue, Mar 03, 2015 at 09:32:29AM +0000, Juri Lelli wrote: >Hi, > >[+Kirill] > >On 26/02/2015 02:38, Wanpeng Li wrote: >> Dl task who is not on queue and it is also the curr task simultaneously >> can not happen. In addition, pull since the priority of a not on queue >> dl task doesn't make any sense. >> >> This patch fix it by don't pull if dl task who's prio changed is not on >> queue. >> > >So, this is something that was already raised by Kirill, but I always >forgot to fix :/. Thanks for reminding me! > >I have this fix:
Cool, your patch looks good to me.
Regards, Wanpeng Li
> >>From 8fcb04eee2d76042970e9561d253d1bc1fe4cc2b Mon Sep 17 00:00:00 2001 >From: Juri Lelli <juri.lelli@arm.com> >Date: Tue, 3 Mar 2015 07:51:56 +0000 >Subject: [PATCH] sched/deadline: cleanup prio_changed_dl() > >rq->curr task can't be in "dequeued" state in prio_changed_dl() >(The only place we can have that is __schedule()), but it can >be throttled, in which case we shouldn't do balancing. > >Also modify the "else" branch, which is dead code (switched_to_dl() >is not interested in dequeued tasks and we are not interested >in balancing in this case), to take into account updates to not >running tasks. > >Signed-off-by: Juri Lelli <juri.lelli@arm.com> >Suggested-by: Kirill Tkhai <ktkhai@parallels.com> >Suggested-by: Wanpeng Li <wanpeng.li@linux.intel.com> >Cc: Ingo Molnar <mingo@redhat.com> >Cc: Peter Zijlstra <peterz@infradead.org> >Cc: Juri Lelli <juri.lelli@gmail.com> >Cc: linux-kernel@vger.kernel.org >--- > kernel/sched/deadline.c | 16 +++++++++++++--- > 1 file changed, 13 insertions(+), 3 deletions(-) > >diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c >index cfa45c1..9d83748 100644 >--- a/kernel/sched/deadline.c >+++ b/kernel/sched/deadline.c >@@ -1759,7 +1759,10 @@ static void switched_to_dl(struct rq *rq, struct task_struct *p) > static void prio_changed_dl(struct rq *rq, struct task_struct *p, > int oldprio) > { >- if (task_on_rq_queued(p) || rq->curr == p) { >+ if (!on_dl_rq(&p->dl)) >+ return; >+ >+ if (rq->curr == p) { > #ifdef CONFIG_SMP > /* > * This might be too much, but unfortunately >@@ -1786,8 +1789,15 @@ static void prio_changed_dl(struct rq *rq, struct task_struct *p, > */ > resched_curr(rq); > #endif /* CONFIG_SMP */ >- } else >- switched_to_dl(rq, p); >+ } else { >+ /* >+ * This task is not running, so if its deadline is >+ * now more imminent than that of the current running >+ * task then reschedule. >+ */ >+ if (dl_time_before(p->dl.deadline, rq->curr->dl.deadline)) >+ resched_curr(rq); >+ } > } > > const struct sched_class dl_sched_class = { >-- >2.3.0 > >> Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com> >> --- >> kernel/sched/deadline.c | 5 ++++- >> 1 file changed, 4 insertions(+), 1 deletion(-) >> >> diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c >> index 49f92c8..ca391c0 100644 >> --- a/kernel/sched/deadline.c >> +++ b/kernel/sched/deadline.c >> @@ -1728,7 +1728,10 @@ static void switched_to_dl(struct rq *rq, struct task_struct *p) >> static void prio_changed_dl(struct rq *rq, struct task_struct *p, >> int oldprio) >> { >> - if (task_on_rq_queued(p) || rq->curr == p) { >> + if (!task_on_rq_queued(p)) >> + return; >> + >> + if (rq->curr == p) { >> #ifdef CONFIG_SMP >> /* >> * This might be too much, but unfortunately >>
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