From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933418AbcE3Pwd (ORCPT ); Mon, 30 May 2016 11:52:33 -0400 Received: from mail-wm0-f51.google.com ([74.125.82.51]:33774 "EHLO mail-wm0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932930AbcE3Pwc (ORCPT ); Mon, 30 May 2016 11:52:32 -0400 From: Vincent Guittot To: peterz@infradead.org, mingo@kernel.org, linux-kernel@vger.kernel.org Cc: yuyang.du@intel.com, dietmar.eggemann@arm.com, Vincent Guittot Subject: [PATCH v3] sched: fix first task of a task group is attached twice Date: Mon, 30 May 2016 17:52:20 +0200 Message-Id: <1464623541-25429-1-git-send-email-vincent.guittot@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Signed-off-by: Vincent Guittot --- v3: - add initialization of load_last_update_time_copy for not 64bits system - move init into init_cfs_rq v2: - rq_clock_task(rq_of(cfs_rq)) can't be used because lock is not held kernel/sched/fair.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 218f8e8..86be9c1 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -8459,6 +8459,16 @@ void init_cfs_rq(struct cfs_rq *cfs_rq) cfs_rq->min_vruntime_copy = cfs_rq->min_vruntime; #endif #ifdef CONFIG_SMP + /* + * Set last_update_time to something different from 0 to make + * sure the 1st sched_entity will not be attached twice: once + * when attaching the task to the group and one more time when + * enqueueing the task. + */ + cfs_rq->avg.last_update_time = 1; +#ifndef CONFIG_64BIT + cfs_rq->load_last_update_time_copy = 1; +#endif atomic_long_set(&cfs_rq->removed_load_avg, 0); atomic_long_set(&cfs_rq->removed_util_avg, 0); #endif -- 1.9.1