From patchwork Tue Jul 7 18:23:54 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Morten Rasmussen X-Patchwork-Id: 6736561 Return-Path: X-Original-To: patchwork-linux-pm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 0177CC05AC for ; Tue, 7 Jul 2015 18:23:08 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 30A0A20398 for ; Tue, 7 Jul 2015 18:23:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3C82B20668 for ; Tue, 7 Jul 2015 18:23:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932824AbbGGSWq (ORCPT ); Tue, 7 Jul 2015 14:22:46 -0400 Received: from foss.arm.com ([217.140.101.70]:37414 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932782AbbGGSW3 (ORCPT ); Tue, 7 Jul 2015 14:22:29 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B152C390; Tue, 7 Jul 2015 11:22:55 -0700 (PDT) Received: from e105550-lin.cambridge.arm.com (e105550-lin.cambridge.arm.com [10.2.131.193]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 9D2873F23A; Tue, 7 Jul 2015 11:22:26 -0700 (PDT) From: Morten Rasmussen To: peterz@infradead.org, mingo@redhat.com Cc: 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: [RFCv5 PATCH 11/46] sched: Remove blocked load and utilization contributions of dying tasks Date: Tue, 7 Jul 2015 19:23:54 +0100 Message-Id: <1436293469-25707-12-git-send-email-morten.rasmussen@arm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1436293469-25707-1-git-send-email-morten.rasmussen@arm.com> References: <1436293469-25707-1-git-send-email-morten.rasmussen@arm.com> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Spam-Status: No, score=-7.7 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Tasks being dequeued for the last time (state == TASK_DEAD) are dequeued with the DEQUEUE_SLEEP flag which causes their load and utilization contributions to be added to the runqueue blocked load and utilization. Hence they will contain load or utilization that is gone away. The issue only exists for the root cfs_rq as cgroup_exit() doesn't set DEQUEUE_SLEEP for task group exits. If runnable+blocked load is to be used as a better estimate for cpu load the dead task contributions need to be removed to prevent load_balance() (idle_balance() in particular) from over-estimating the cpu load. cc: Ingo Molnar cc: Peter Zijlstra Signed-off-by: Morten Rasmussen --- kernel/sched/fair.c | 2 ++ 1 file changed, 2 insertions(+) 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);