From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932505AbdELDeh (ORCPT ); Thu, 11 May 2017 23:34:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57938 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932439AbdELDeg (ORCPT ); Thu, 11 May 2017 23:34:36 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com D81B980C0C Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=xpang@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com D81B980C0C Reply-To: xlpang@redhat.com Subject: Re: [PATCH] sched/deadline: Zero out positive runtime after throttling constrained tasks References: <1494421417-27550-1-git-send-email-xlpang@redhat.com> <20170510093633.5a83ee4d@gandalf.local.home> <5913C0A9.9050209@redhat.com> To: Steven Rostedt , Xunlei Pang Cc: linux-kernel@vger.kernel.org, Peter Zijlstra , Juri Lelli , Ingo Molnar , Luca Abeni , Daniel Bristot de Oliveira From: Xunlei Pang Message-ID: <59152D9E.60204@redhat.com> Date: Fri, 12 May 2017 11:35:58 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <5913C0A9.9050209@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Fri, 12 May 2017 03:34:36 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/11/2017 at 09:38 AM, Xunlei Pang wrote: > On 05/10/2017 at 09:36 PM, Steven Rostedt wrote: >> 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? > It sounds a good idea, will try to add that to "/proc//sched". > > Looks like we should also catch and handle the deadline miss in dl_runtime_exceeded(), > I guess we can add the accounting together. Hi all, Thanks for all your valuable review! FYI: I just sent v2 added two more patches. Regards, Xunlei