From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752205AbaKZAq3 (ORCPT ); Tue, 25 Nov 2014 19:46:29 -0500 Received: from mga01.intel.com ([192.55.52.88]:59901 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752085AbaKZApT (ORCPT ); Tue, 25 Nov 2014 19:45:19 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,459,1413270000"; d="scan'208";a="628294357" From: Wanpeng Li To: Ingo Molnar , Peter Zijlstra Cc: Juri Lelli , Kirill Tkhai , linux-kernel@vger.kernel.org, Wanpeng Li Subject: [PATCH v6 5/7] sched/fair: fix idle balance when remaining tasks are all non-CFS tasks Date: Wed, 26 Nov 2014 08:44:05 +0800 Message-Id: <1416962647-76792-6-git-send-email-wanpeng.li@linux.intel.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1416962647-76792-1-git-send-email-wanpeng.li@linux.intel.com> References: <1416962647-76792-1-git-send-email-wanpeng.li@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The overload indicator is used for knowing when we can totally avoid load balancing to a cpu that is about to go idle. We can avoid load balancing when no cpu has cfs task and both rt and deadline have push/pull mechanism to do their own balancing. However, rq->nr_running on behalf of the total number of each class tasks on the cpu, do idle balance when remaining tasks are all non-CFS tasks does not make any sense. This patch fix it by idle balance when there are still other CFS tasks in the rq's root domain. Signed-off-by: Wanpeng Li --- kernel/sched/fair.c | 2 +- kernel/sched/sched.h | 3 ++- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index a1c9267..8b7e131 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6192,7 +6192,7 @@ static inline void update_sg_lb_stats(struct lb_env *env, sgs->group_load += load; sgs->sum_nr_running += rq->cfs.h_nr_running; - if (rq->nr_running > 1) + if (rq->nr_running > 1 && rq->cfs.h_nr_running > 0) *overload = true; #ifdef CONFIG_NUMA_BALANCING diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 31f1e4d..f7dd978 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1269,7 +1269,8 @@ static inline void add_nr_running(struct rq *rq, unsigned count) rq->nr_running = prev_nr + count; - if (prev_nr < 2 && rq->nr_running >= 2) { + if (prev_nr < 2 && rq->nr_running >= 2 && + rq->cfs.h_nr_running > 0) { #ifdef CONFIG_SMP if (!rq->rd->overload) rq->rd->overload = true; -- 1.9.1