From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754021AbbIGJpb (ORCPT ); Mon, 7 Sep 2015 05:45:31 -0400 Received: from blu004-omc1s18.hotmail.com ([65.55.116.29]:61482 "EHLO BLU004-OMC1S18.hotmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751489AbbIGJp2 (ORCPT ); Mon, 7 Sep 2015 05:45:28 -0400 X-TMN: [LRekLyM+RMZC6cYKPFNb8j3/Y9FGhOUbE8BRxibfYww=] X-Originating-Email: [wanpeng.li@hotmail.com] Message-ID: From: Wanpeng Li To: Ingo Molnar , Peter Zijlstra CC: linux-kernel@vger.kernel.org, Wanpeng Li Subject: [PATCH] sched: fix lose fair sleeper bonus in switch_to_fair() Date: Mon, 7 Sep 2015 17:45:20 +0800 X-Mailer: git-send-email 1.9.1 X-OriginalArrivalTime: 07 Sep 2015 09:45:26.0141 (UTC) FILETIME=[EC6502D0:01D0E951] MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The sleeper task will be normalized when moved from fair_sched_class, in order that vruntime will be adjusted either the task is running or sleeping when moved back. The nomalization in switch_to_fair for sleep task will result in lose fair sleeper bonus in place_entity() once the vruntime - cfs_rq->min_vruntime is big when moved from fair_sched_class. This patch fix it by adjusting vruntime just during migrating as original codes since the vruntime of the task has usually NOT been normalized in this case. Signed-off-by: Wanpeng Li --- kernel/sched/fair.c | 11 +++++++---- 1 files changed, 7 insertions(+), 4 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index d26d3b7..eb9aa35 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -8005,9 +8005,6 @@ static void attach_task_cfs_rq(struct task_struct *p) /* Synchronize task with its cfs_rq */ attach_entity_load_avg(cfs_rq, se); - - if (!vruntime_normalized(p)) - se->vruntime += cfs_rq->min_vruntime; } static void switched_from_fair(struct rq *rq, struct task_struct *p) @@ -8066,14 +8063,20 @@ void init_cfs_rq(struct cfs_rq *cfs_rq) #ifdef CONFIG_FAIR_GROUP_SCHED static void task_move_group_fair(struct task_struct *p) { + struct sched_entity *se = &p->se; + struct cfs_rq *cfs_rq = cfs_rq_of(se); + detach_task_cfs_rq(p); set_task_rq(p, task_cpu(p)); #ifdef CONFIG_SMP /* Tell se's cfs_rq has been changed -- migrated */ - p->se.avg.last_update_time = 0; + se->avg.last_update_time = 0; #endif attach_task_cfs_rq(p); + + if (!vruntime_normalized(p)) + se->vruntime += cfs_rq->min_vruntime; } void free_fair_sched_group(struct task_group *tg) -- 1.7.1