From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753248Ab2HMQwb (ORCPT ); Mon, 13 Aug 2012 12:52:31 -0400 Received: from terminus.zytor.com ([198.137.202.10]:33511 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753060Ab2HMQw3 (ORCPT ); Mon, 13 Aug 2012 12:52:29 -0400 Date: Mon, 13 Aug 2012 09:52:13 -0700 From: tip-bot for Mike Galbraith Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, a.p.zijlstra@chello.nl, efault@gmx.de, tglx@linutronix.de Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl, efault@gmx.de, tglx@linutronix.de In-Reply-To: <1344326558.6968.25.camel@marge.simpson.net> References: <1344326558.6968.25.camel@marge.simpson.net> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/urgent] sched,rt: fix isolated CPUs leaving root_task_group indefinitely throttled Git-Commit-ID: e221d028bb08b47e624c5f0a31732c642db9d19a X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.6 (terminus.zytor.com [127.0.0.1]); Mon, 13 Aug 2012 09:52:19 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: e221d028bb08b47e624c5f0a31732c642db9d19a Gitweb: http://git.kernel.org/tip/e221d028bb08b47e624c5f0a31732c642db9d19a Author: Mike Galbraith AuthorDate: Tue, 7 Aug 2012 10:02:38 +0200 Committer: Thomas Gleixner CommitDate: Mon, 13 Aug 2012 18:41:55 +0200 sched,rt: fix isolated CPUs leaving root_task_group indefinitely throttled Root task group bandwidth replenishment must service all CPUs, regardless of where the timer was last started, and regardless of the isolation mechanism, lest 'Quoth the Raven, "Nevermore"' become rt scheduling policy. Signed-off-by: Mike Galbraith Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1344326558.6968.25.camel@marge.simpson.net Signed-off-by: Thomas Gleixner --- kernel/sched/rt.c | 13 +++++++++++++ 1 files changed, 13 insertions(+), 0 deletions(-) diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 573e1ca..944cb68 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -788,6 +788,19 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) const struct cpumask *span; span = sched_rt_period_mask(); +#ifdef CONFIG_RT_GROUP_SCHED + /* + * FIXME: isolated CPUs should really leave the root task group, + * whether they are isolcpus or were isolated via cpusets, lest + * the timer run on a CPU which does not service all runqueues, + * potentially leaving other CPUs indefinitely throttled. If + * isolation is really required, the user will turn the throttle + * off to kill the perturbations it causes anyway. Meanwhile, + * this maintains functionality for boot and/or troubleshooting. + */ + if (rt_b == &root_task_group.rt_bandwidth) + span = cpu_online_mask; +#endif for_each_cpu(i, span) { int enqueue = 0; struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i);