From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755611AbeDZLuA (ORCPT ); Thu, 26 Apr 2018 07:50:00 -0400 Received: from merlin.infradead.org ([205.233.59.134]:48088 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755238AbeDZLt7 (ORCPT ); Thu, 26 Apr 2018 07:49:59 -0400 Date: Thu, 26 Apr 2018 13:49:56 +0200 From: Peter Zijlstra To: Vincent Guittot Cc: mingo@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] sched/fair: use RETRY_TASK in idle_balance Message-ID: <20180426114956.GJ4064@hirez.programming.kicks-ass.net> References: <1524739022-7788-1-git-send-email-vincent.guittot@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1524739022-7788-1-git-send-email-vincent.guittot@linaro.org> User-Agent: Mutt/1.9.3 (2018-01-21) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 26, 2018 at 12:37:02PM +0200, Vincent Guittot wrote: > Use RETRY_TASK in idle_balance when we want select_task_rq() function to > rerun the complete task selection path > > Signed-off-by: Vincent Guittot > --- > kernel/sched/fair.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index 0951d1c..ba49f83 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -9862,7 +9862,7 @@ static int idle_balance(struct rq *this_rq, struct rq_flags *rf) > > /* Is there a task of a high priority class? */ > if (this_rq->nr_running != this_rq->cfs.h_nr_running) > - pulled_task = -1; > + pulled_task = RETRY_TASK; This doesn't make sense, pulled_task is an integer, not a task pointer. Also see how the caller in select_task_rq_fair() converts a negative into RETRY_TASK.