From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1423935AbcFIHNe (ORCPT ); Thu, 9 Jun 2016 03:13:34 -0400 Received: from mga09.intel.com ([134.134.136.24]:15804 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161400AbcFIHN3 (ORCPT ); Thu, 9 Jun 2016 03:13:29 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.26,443,1459839600"; d="scan'208";a="972042486" From: Yuyang Du To: peterz@infradead.org, mingo@kernel.org, linux-kernel@vger.kernel.org Cc: bsegall@google.com, pjt@google.com, morten.rasmussen@arm.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, matt@codeblueprint.co.uk, Yuyang Du Subject: [PATCH v5 4/5] sched/fair: Skip detach sched avgs for new task when changing task groups Date: Thu, 9 Jun 2016 07:15:53 +0800 Message-Id: <1465427754-28897-5-git-send-email-yuyang.du@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1465427754-28897-1-git-send-email-yuyang.du@intel.com> References: <1465427754-28897-1-git-send-email-yuyang.du@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Newly forked task has not been enqueued, so should not be removed from cfs_rq in task_move_group_fair(). To do so, we identify newly forked tasks by their sched_avg's last_update_time in detach_entity_load_avg(). Signed-off-by: Yuyang Du --- kernel/sched/fair.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 6e870c6..e0f219b 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2943,6 +2943,10 @@ static inline void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_en static void detach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) { + /* Newly forked tasks are not attached yet. */ + if (!se->avg.last_update_time) + return; + __update_load_avg(cfs_rq->avg.last_update_time, cpu_of(rq_of(cfs_rq)), &se->avg, se->on_rq * scale_load_down(se->load.weight), cfs_rq->curr == se, NULL); -- 1.7.9.5