Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755214AbaJUKME (ORCPT ); Tue, 21 Oct 2014 06:12:04 -0400 Received: from service87.mimecast.com ([91.220.42.44]:59867 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754746AbaJUKMB convert rfc822-to-8bit (ORCPT ); Tue, 21 Oct 2014 06:12:01 -0400 Message-ID: <5446316B.4070707@arm.com> Date: Tue, 21 Oct 2014 11:11:55 +0100 From: Juri Lelli User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: Wanpeng Li , Ingo Molnar , Peter Zijlstra CC: Kirill V Tkhai , Steven Rostedt , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH RESEND v2] sched/deadline: do not try to push tasks if pinned task switches to dl References: <1412989095-7507-1-git-send-email-wanpeng.li@linux.intel.com> In-Reply-To: <1412989095-7507-1-git-send-email-wanpeng.li@linux.intel.com> X-OriginalArrivalTime: 21 Oct 2014 10:11:55.0651 (UTC) FILETIME=[71373D30:01CFED17] X-MC-Unique: 114102111115607201 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 11/10/14 01:58, Wanpeng Li wrote: > As Kirill mentioned(https://lkml.org/lkml/2013/1/29/118): > | If rq has already had 2 or more pushable tasks and we try to add a > | pinned task then call of push_rt_task will just waste a time. > > Just switched pinned task is not able to be pushed. If the rq had had ^ has > several dl tasks before they have already been considered as candidates > to be pushed (or pulled). This patch done the same behavior as rt class ^ implements? aligns to... > which introduced by commit 10447917551e ("sched/rt: Do not try to push > tasks if pinned task switches to RT"). > > Signed-off-by: Wanpeng Li > --- > v1 -> v2: > * use 12 or more chars for the git commit ID > > kernel/sched/deadline.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c > index abfaf3d..cf7c9b6 100644 > --- a/kernel/sched/deadline.c > +++ b/kernel/sched/deadline.c > @@ -1603,7 +1603,8 @@ static void switched_to_dl(struct rq *rq, struct task_struct *p) > > if (task_on_rq_queued(p) && rq->curr != p) { > #ifdef CONFIG_SMP > - if (rq->dl.overloaded && push_dl_task(rq) && rq != task_rq(p)) > + if (p->nr_cpus_allowed > 1 && rq->dl.overloaded > + && push_dl_task(rq) && rq != task_rq(p)) I'd personally align this && to p->nr_cpus_allowed, but that's just my personal taste, though. :) > /* Only reschedule if pushing failed */ > check_resched = 0; > #endif /* CONFIG_SMP */ > Anyway, the change looks good, thanks! Best, - Juri -- 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/