Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934310AbbHKLjl (ORCPT ); Tue, 11 Aug 2015 07:39:41 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:58105 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934028AbbHKLjj (ORCPT ); Tue, 11 Aug 2015 07:39:39 -0400 Date: Tue, 11 Aug 2015 13:39:27 +0200 From: Peter Zijlstra To: Morten Rasmussen Cc: mingo@redhat.com, vincent.guittot@linaro.org, daniel.lezcano@linaro.org, Dietmar Eggemann , yuyang.du@intel.com, mturquette@baylibre.com, rjw@rjwysocki.net, Juri Lelli , sgurrappadi@nvidia.com, pang.xunlei@zte.com.cn, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Subject: Re: [RFCv5 PATCH 11/46] sched: Remove blocked load and utilization contributions of dying tasks Message-ID: <20150811113927.GT19282@twins.programming.kicks-ass.net> References: <1436293469-25707-1-git-send-email-morten.rasmussen@arm.com> <1436293469-25707-12-git-send-email-morten.rasmussen@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1436293469-25707-12-git-send-email-morten.rasmussen@arm.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1092 Lines: 25 On Tue, Jul 07, 2015 at 07:23:54PM +0100, Morten Rasmussen wrote: > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index 775b0c7..fa12ce5 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -3217,6 +3217,8 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) > * Update run-time statistics of the 'current'. > */ > update_curr(cfs_rq); > + if (entity_is_task(se) && task_of(se)->state == TASK_DEAD) > + flags &= !DEQUEUE_SLEEP; > dequeue_entity_load_avg(cfs_rq, se, flags & DEQUEUE_SLEEP); > > update_stats_dequeue(cfs_rq, se); I know this is entirely redundant at this point (we took Yuyang's patches), but this is the wrong way to go about doing this. You add extra code the hot dequeue path for something that 'never' happens. We have the sched_class::task_dead call for that. -- 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/