From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754754AbdEKBh3 (ORCPT ); Wed, 10 May 2017 21:37:29 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53206 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753822AbdEKBh2 (ORCPT ); Wed, 10 May 2017 21:37:28 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 0DB524E35B Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=xpang@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 0DB524E35B 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> 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: <5913C0A9.9050209@redhat.com> Date: Thu, 11 May 2017 09:38:49 +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: <20170510093633.5a83ee4d@gandalf.local.home> 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 [10.5.110.38]); Thu, 11 May 2017 01:37:28 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Regards, Xunlei