Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754541AbaJWX1X (ORCPT ); Thu, 23 Oct 2014 19:27:23 -0400 Received: from mail-pa0-f45.google.com ([209.85.220.45]:39882 "EHLO mail-pa0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754288AbaJWX1U (ORCPT ); Thu, 23 Oct 2014 19:27:20 -0400 Message-ID: <54498ED2.1070308@gmail.com> Date: Fri, 24 Oct 2014 07:27:14 +0800 From: Wanpeng Li User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Kirill Tkhai , linux-kernel@vger.kernel.org CC: peterz@infradead.org, pjt@google.com, oleg@redhat.com, rostedt@goodmis.org, umgwanakikbuti@gmail.com, tkhai@yandex.ru, tim.c.chen@linux.intel.com, mingo@kernel.org, nicolas.pitre@linaro.org Subject: Re: [PATCH v4 1/6] sched/fair: Fix reschedule which is generated on throttled cfs_rq References: <20140806075138.24858.23816.stgit@tkhai> <1407312361.8424.35.camel@tkhai> In-Reply-To: <1407312361.8424.35.camel@tkhai> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Kirill, 8/6/14, 4:06 PM, Kirill Tkhai: > (sched_entity::on_rq == 1) does not guarantee the task is pickable; > changes on throttled cfs_rq must not lead to reschedule. Why (sched_entity::on_rq == 1) doesn't guarantee the task is pickable since entity will be dequeued during throttling cfs_rq? > > Check for task_struct::on_rq instead. Do you mean task_struct::on_rq will be cleared during throttling cfs_rq? I can't find codes do this. Regards, Wanpeng Li > > Signed-off-by: Kirill Tkhai > --- > kernel/sched/fair.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index bfa3c86..6f0ce2b 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -7465,7 +7465,7 @@ static void task_fork_fair(struct task_struct *p) > static void > prio_changed_fair(struct rq *rq, struct task_struct *p, int oldprio) > { > - if (!p->se.on_rq) > + if (!p->on_rq) > return; > > /* > @@ -7521,15 +7521,15 @@ static void switched_from_fair(struct rq *rq, struct task_struct *p) > */ > static void switched_to_fair(struct rq *rq, struct task_struct *p) > { > - struct sched_entity *se = &p->se; > #ifdef CONFIG_FAIR_GROUP_SCHED > + struct sched_entity *se = &p->se; > /* > * Since the real-depth could have been changed (only FAIR > * class maintain depth value), reset depth properly. > */ > se->depth = se->parent ? se->parent->depth + 1 : 0; > #endif > - if (!se->on_rq) > + if (!p->on_rq) > return; > > /* > > > > -- > 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/ -- 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/