From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bombadil.infradead.org ([198.137.202.133]:40442 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389388AbeGTNe2 (ORCPT ); Fri, 20 Jul 2018 09:34:28 -0400 Date: Fri, 20 Jul 2018 14:46:15 +0200 From: Peter Zijlstra To: Daniel Bristot de Oliveira Cc: linux-kernel@vger.kernel.org, Clark Williams , Juri Lelli , Luca Abeni , Tommaso Cucinotta , Steven Rostedt , Ingo Molnar , stable@vger.kernel.org Subject: Re: [PATCH V3] sched/deadline: Update rq_clock of later_rq when pushing a task Message-ID: <20180720124615.GM2476@hirez.programming.kicks-ass.net> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: stable-owner@vger.kernel.org List-ID: On Fri, Jul 20, 2018 at 11:16:30AM +0200, Daniel Bristot de Oliveira wrote: > diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c > index fbfc3f1d368a..8b50eea4b607 100644 > --- a/kernel/sched/deadline.c > +++ b/kernel/sched/deadline.c > @@ -2090,8 +2090,14 @@ static int push_dl_task(struct rq *rq) > sub_rq_bw(&next_task->dl, &rq->dl); > set_task_cpu(next_task, later_rq->cpu); > add_rq_bw(&next_task->dl, &later_rq->dl); > + > + /* > + * Update the later_rq clock here, because the clock is used > + * by the cpufreq_update_util() inside __add_running_bw(). > + */ > + update_rq_clock(later_rq); > add_running_bw(&next_task->dl, &later_rq->dl); > - activate_task(later_rq, next_task, 0); > + activate_task(later_rq, next_task, ENQUEUE_NOCLOCK); > ret = 1; > > resched_curr(later_rq); Why isn't push_rt_task() affected by the very same issue?