From: Mike Galbraith <umgwanakikbuti@gmail.com>
To: Tejun Heo <tj@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Michal Hocko <mhocko@kernel.org>, Jiri Slaby <jslaby@suse.cz>,
Thomas Gleixner <tglx@linutronix.de>,
Petr Mladek <pmladek@suse.com>, Jan Kara <jack@suse.cz>,
Ben Hutchings <ben@decadent.org.uk>,
Sasha Levin <sasha.levin@oracle.com>, Shaohua Li <shli@fb.com>,
LKML <linux-kernel@vger.kernel.org>,
stable <stable@vger.kernel.org>,
Daniel Bilik <daniel.bilik@neosystem.cz>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: Re: Crashes with 874bbfe600a6 in 3.18.25
Date: Tue, 09 Feb 2016 18:56:53 +0100 [thread overview]
Message-ID: <1455040613.3604.11.camel@gmail.com> (raw)
In-Reply-To: <20160209175400.GC3741@mtj.duckdns.org>
On Tue, 2016-02-09 at 12:54 -0500, Tejun Heo wrote:
> Hello, Mike.
>
> On Tue, Feb 09, 2016 at 06:04:04PM +0100, Mike Galbraith wrote:
> > workqueue: schedule WORK_CPU_UNBOUND work on wq_unbound_cpumask
> > CPUs
> >
> > WORK_CPU_UNBOUND work items queued to a bound workqueue always run
> > locally. This is a good thing normally, but not when the user has
> > asked us to keep unbound work away from certain CPUs. Round robin
> > these to wq_unbound_cpumask CPUs instead, as perturbation avoidance
> > trumps performance.
>
> I don't think doing this by default for everyone is a good idea. A
> lot of workqueue usages tend to touch whatever the scheduler was
> touching after all. Doing things per-cpu is generally a pretty good
> thing.
It doesn't do anything unless the user twiddles the mask to exclude
certain (think no_hz_full) CPUs, so there are no clueless victims.
-Mike
next prev parent reply other threads:[~2016-02-09 17:57 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-20 21:19 Crashes with 874bbfe600a6 in 3.18.25 Jan Kara
2016-01-20 21:39 ` Shaohua Li
2016-01-21 9:52 ` Jan Kara
2016-01-21 13:29 ` Sasha Levin
2016-01-22 1:10 ` Sasha Levin
2016-01-22 16:09 ` Tejun Heo
2016-01-23 2:20 ` Ben Hutchings
2016-01-23 16:11 ` Thomas Gleixner
2016-01-26 9:34 ` Jan Kara
2016-01-26 9:34 ` Jan Kara
2016-01-26 9:49 ` Thomas Gleixner
2016-01-26 9:49 ` Thomas Gleixner
2016-01-26 11:14 ` Petr Mladek
2016-01-26 11:14 ` Petr Mladek
2016-01-26 13:09 ` Thomas Gleixner
2016-01-26 13:09 ` Thomas Gleixner
2016-02-03 9:35 ` Jiri Slaby
2016-02-03 10:41 ` Thomas Gleixner
2016-02-03 12:28 ` Michal Hocko
2016-02-03 16:24 ` Tejun Heo
2016-02-03 16:48 ` Michal Hocko
2016-02-03 16:59 ` Tejun Heo
2016-02-04 6:37 ` Michal Hocko
2016-02-04 7:40 ` Michal Hocko
2016-02-03 17:01 ` Mike Galbraith
2016-02-03 17:06 ` Tejun Heo
2016-02-03 17:13 ` Mike Galbraith
2016-02-03 17:15 ` Tejun Heo
2016-02-04 2:00 ` Mike Galbraith
2016-02-05 16:49 ` Tejun Heo
2016-02-05 20:47 ` Mike Galbraith
2016-02-05 20:54 ` Tejun Heo
2016-02-05 20:59 ` Mike Galbraith
2016-02-05 21:06 ` Tejun Heo
2016-02-06 13:07 ` Henrique de Moraes Holschuh
2016-02-07 5:19 ` Mike Galbraith
2016-02-07 5:59 ` Mike Galbraith
2016-02-09 15:31 ` Mike Galbraith
2016-02-09 16:39 ` Linus Torvalds
2016-02-09 16:50 ` Tejun Heo
2016-02-09 17:04 ` Mike Galbraith
2016-02-09 17:54 ` Tejun Heo
2016-02-09 17:56 ` Mike Galbraith [this message]
2016-02-09 18:02 ` Mike Galbraith
2016-02-09 18:27 ` Tejun Heo
2016-02-09 17:04 ` Linus Torvalds
2016-02-09 17:51 ` Tejun Heo
2016-02-09 18:06 ` Linus Torvalds
2016-02-04 10:04 ` Mike Galbraith
2016-02-04 10:46 ` Thomas Gleixner
2016-02-04 11:07 ` Mike Galbraith
2016-02-04 11:20 ` Jan Kara
2016-02-04 16:39 ` Daniel Bilik
2016-02-05 2:40 ` Mike Galbraith
2016-02-05 8:11 ` Daniel Bilik
2016-02-05 8:33 ` Mike Galbraith
2016-02-03 18:46 ` Thomas Gleixner
2016-02-03 19:01 ` Tejun Heo
2016-02-03 19:05 ` Thomas Gleixner
2016-02-03 19:15 ` Tejun Heo
2016-02-05 5:44 ` Mike Galbraith
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