From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752987AbdEJNgj (ORCPT ); Wed, 10 May 2017 09:36:39 -0400 Received: from mail.kernel.org ([198.145.29.136]:56338 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750733AbdEJNgi (ORCPT ); Wed, 10 May 2017 09:36:38 -0400 Date: Wed, 10 May 2017 09:36:33 -0400 From: Steven Rostedt To: Xunlei Pang Cc: linux-kernel@vger.kernel.org, Peter Zijlstra , Juri Lelli , Ingo Molnar , Luca Abeni , Daniel Bristot de Oliveira Subject: Re: [PATCH] sched/deadline: Zero out positive runtime after throttling constrained tasks Message-ID: <20170510093633.5a83ee4d@gandalf.local.home> In-Reply-To: <1494421417-27550-1-git-send-email-xlpang@redhat.com> References: <1494421417-27550-1-git-send-email-xlpang@redhat.com> X-Mailer: Claws Mail 3.14.0 (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 10 May 2017 21:03:37 +0800 Xunlei Pang wrote: > When a contrained task is throttled by dl_check_constrained_dl(), > it may carry the remaining positive runtime, as a result when > dl_task_timer() fires and calls replenish_dl_entity(), it will > not be replenished correctly due to the positive dl_se->runtime. > > This patch assigns its runtime to 0 if positive after throttling. > > Fixes: df8eac8cafce ("sched/deadline: Throttle a constrained deadline task activated after the deadline) > Cc: Daniel Bristot de Oliveira > Signed-off-by: Xunlei Pang > --- > kernel/sched/deadline.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c > index a2ce590..d3d291e 100644 > --- a/kernel/sched/deadline.c > +++ b/kernel/sched/deadline.c > @@ -723,6 +723,8 @@ static inline void dl_check_constrained_dl(struct sched_dl_entity *dl_se) > if (unlikely(dl_se->dl_boosted || !start_dl_timer(p))) > return; > dl_se->dl_throttled = 1; > + if (dl_se->runtime > 0) > + dl_se->runtime = 0; This makes sense to me, but should we have any accounting for runtime that was missed due to wakeups and such? -- Steve > } > } >