Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932608AbaJVJdK (ORCPT ); Wed, 22 Oct 2014 05:33:10 -0400 Received: from service87.mimecast.com ([91.220.42.44]:43884 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751347AbaJVJdI convert rfc822-to-8bit (ORCPT ); Wed, 22 Oct 2014 05:33:08 -0400 Message-ID: <544779D1.4060309@arm.com> Date: Wed, 22 Oct 2014 10:33:05 +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 v3] sched/deadline: do not try to push tasks if pinned task switches to dl References: <1413938203-224610-1-git-send-email-wanpeng.li@linux.intel.com> In-Reply-To: <1413938203-224610-1-git-send-email-wanpeng.li@linux.intel.com> X-OriginalArrivalTime: 22 Oct 2014 09:33:04.0824 (UTC) FILETIME=[2E590380:01CFEDDB] X-MC-Unique: 114102210330600101 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 On 22/10/14 01:36, 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 has had > several dl tasks before they have already been considered as candidates > to be pushed (or pulled). This patch implements the same behavior as rt > class which introduced by commit 10447917551e ("sched/rt: Do not try to > push tasks if pinned task switches to RT"). > > Signed-off-by: Wanpeng Li > --- > v2 -> v3: > * cleanup patch description > * align && to p->nr_cpus_allowed > 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..bd5e479 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)) > /* Only reschedule if pushing failed */ > check_resched = 0; > #endif /* CONFIG_SMP */ > 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/