Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933189AbaJUQdu (ORCPT ); Tue, 21 Oct 2014 12:33:50 -0400 Received: from relay.parallels.com ([195.214.232.42]:42833 "EHLO relay.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933121AbaJUQds (ORCPT ); Tue, 21 Oct 2014 12:33:48 -0400 Message-ID: <1413909224.19914.126.camel@tkhai> Subject: Re: [PATCH v2 2/3] sched/dl: Cleanup prio_changed_dl() From: Kirill Tkhai To: Juri Lelli CC: Peter Zijlstra , Kirill Tkhai , "linux-kernel@vger.kernel.org" , Ingo Molnar , Juri Lelli Date: Tue, 21 Oct 2014 20:33:44 +0400 In-Reply-To: <544688A1.7010403@arm.com> References: <20140930210412.5258.35299.stgit@localhost> <20140930210428.5258.32223.stgit@localhost> <20141002093600.GC2849@worktop.programming.kicks-ass.net> <1412243541.20287.28.camel@tkhai> <544688A1.7010403@arm.com> Organization: Parallels Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.8.5-2+b3 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Originating-IP: [10.30.26.172] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org В Вт, 21/10/2014 в 17:24 +0100, Juri Lelli пишет: > Hi Kirill, > > On 02/10/14 10:52, Kirill Tkhai wrote: > > В Чт, 02/10/2014 в 11:36 +0200, Peter Zijlstra пишет: > >> On Wed, Oct 01, 2014 at 01:04:35AM +0400, Kirill Tkhai wrote: > >>> From: Kirill Tkhai > >>> > >>> rq->curr task can't be in "dequeued" state in prio_changed_dl(). > >>> (The only place we can have that is __schedule()). So, we delete > >>> rq->curr check. > >> > >> the CBS timer can throttle it right? > > > > Yeah, it's better to check for on_dl_rq(): > > > > [PATCH]sched/dl: 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()). So, we delete > > rq->curr check. > > > > We shouldn't do balancing if deadline task is throttled too. > > > > Also delete "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). > > > > So, I agree that calling switched_to_dl() makes little sense, > but don't we have to deal with updates to not running tasks as > in rt.c? Something like this maybe? Looks good. No objections from me. > > From 75ee75a5fd76526baaed3ba8a58f3ff7daa89cd6 Mon Sep 17 00:00:00 2001 > From: Juri Lelli > Date: Tue, 21 Oct 2014 17:15:15 +0100 > Subject: [PATCH] sched/deadline: cleanup prio_changed_dl() > > --- > 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 28d6088..1e62e31 100644 > --- a/kernel/sched/deadline.c > +++ b/kernel/sched/deadline.c > @@ -1661,7 +1661,10 @@ 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 > @@ -1688,8 +1691,15 @@ 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 = { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/