From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752045AbcAPNoj (ORCPT ); Sat, 16 Jan 2016 08:44:39 -0500 Received: from www.linutronix.de ([62.245.132.108]:41404 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751607AbcAPNoe (ORCPT ); Sat, 16 Jan 2016 08:44:34 -0500 Date: Sat, 16 Jan 2016 14:43:34 +0100 (CET) From: Thomas Gleixner To: Mike Galbraith cc: Sebastian Andrzej Siewior , Clark Williams , LKML , linux-rt-users , Steven Rostedt Subject: Re: [ANNOUNCE] 4.4-rc6-rt1 In-Reply-To: <1452950602.13755.9.camel@gmail.com> Message-ID: References: <20151223225755.GA21121@linutronix.de> <20151231102441.581ce1e1@sluggy.hsv.redhat.com> <1451632781.9800.22.camel@gmail.com> <20160113175845.GK29964@linutronix.de> <20160114141744.GB17776@linutronix.de> <1452781751.3460.102.camel@gmail.com> <1452783422.3611.8.camel@gmail.com> <1452787507.15549.16.camel@gmail.com> <1452950602.13755.9.camel@gmail.com> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 16 Jan 2016, Mike Galbraith wrote: > On Thu, 2016-01-14 at 17:05 +0100, Mike Galbraith wrote: > > > This is virgin -rt1 modulo fixlet applied to v4.4.0, built with the > > .config from v4.4.0 that built it (modulo RT_FULL) rebuilding itself > > via make -j8. > > > > homer:/root # vmstat 10 > > procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- > > r b swpd free buff cache si so bi bo in cs us sy id wa st > > 0 1 0 14742988 179832 680792 0 0 634 25 326 1196 2 1 89 8 0 > > 8 0 0 14476084 179848 701632 0 0 814 525 2421 12314 11 1 87 1 0 > > 8 0 0 14483232 179864 712656 0 0 165 1628 2404 12320 11 1 87 1 0 > > 8 0 0 14493336 180008 727836 0 0 141 762 2328 11306 11 1 87 0 0 > > 8 0 0 14456436 180024 738356 0 0 159 1478 2336 11939 11 1 87 0 0 > > > > Way too idle, taking forever. > > It now being the weekend... > > sched: Disable default set_cpus_allowed() method during update_migrate_disable(). > > update_migrate_disable() calls class::set_cpus_allowed(), when that method > is set_cpus_allowed_common(), writing to ->cpus_allowed defeats the intent > of migrate_disable(), permanently disabling migration instead. Ha, you found it as well :) > Signed-off-by: Mike Galbraith > --- > kernel/sched/core.c | 2 ++ > 1 file changed, 2 insertions(+) > > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -1205,6 +1205,8 @@ static int migration_cpu_stop(void *data > */ > void set_cpus_allowed_common(struct task_struct *p, const struct cpumask *new_mask) > { > + if (__migrate_disabled(p)) > + return; > cpumask_copy(&p->cpus_allowed, new_mask); > p->nr_cpus_allowed = cpumask_weight(new_mask); > } >