From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753233AbcEZI1T (ORCPT ); Thu, 26 May 2016 04:27:19 -0400 Received: from mail-lb0-f179.google.com ([209.85.217.179]:35864 "EHLO mail-lb0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750854AbcEZI1Q (ORCPT ); Thu, 26 May 2016 04:27:16 -0400 MIME-Version: 1.0 In-Reply-To: <20160525223824.GI18670@intel.com> References: <1464095335-27730-1-git-send-email-vincent.guittot@linaro.org> <1464188472-30086-1-git-send-email-vincent.guittot@linaro.org> <20160525223824.GI18670@intel.com> From: Vincent Guittot Date: Thu, 26 May 2016 10:26:54 +0200 Message-ID: Subject: Re: [PATCH v2] sched: fix first task of a task group is attached twice To: Yuyang Du Cc: Peter Zijlstra , Ingo Molnar , linux-kernel , Dietmar Eggemann Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 26 May 2016 at 00:38, Yuyang Du wrote: > On Wed, May 25, 2016 at 05:01:11PM +0200, Vincent Guittot wrote: >> The cfs_rq->avg.last_update_time is initialize to 0 with the main effect >> that the 1st sched_entity that will be attached, will keep its >> last_update_time set to 0 and will attached once again during the >> enqueue. >> Initialize cfs_rq->avg.last_update_time to 1 instead. > > Actually, the first time (attach_task_cfs_rq()) is called even way > before init_entity_runnable_average(), no? maybe there is an issue during the fork of a task too This patch is about the init of the sched_avg of a task group. The problem happens when the 1st task is moved the group but it's not about the fork of a task