From: Tejun Heo <tj@kernel.org>
To: Josh Don <joshdon@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Juri Lelli <juri.lelli@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Steven Rostedt <rostedt@goodmis.org>,
Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
Valentin Schneider <vschneid@redhat.com>,
linux-kernel@vger.kernel.org,
Joel Fernandes <joel@joelfernandes.org>
Subject: Re: [PATCH v2] sched: async unthrottling for cfs bandwidth
Date: Tue, 1 Nov 2022 09:15:33 -1000 [thread overview]
Message-ID: <Y2FwVX42LIKXSTz3@slm.duckdns.org> (raw)
In-Reply-To: <CABk29Ns1VWEVRYENud4CW3JQPrcr79i_F2PBTANqt3t-LaYCfQ@mail.gmail.com>
Hello,
On Tue, Nov 01, 2022 at 12:11:30PM -0700, Josh Don wrote:
> > Just to better understand the situation, can you give some more details on
> > the scenarios where cgroup_mutex was in the middle of a shitshow?
>
> There have been a couple, I think one of the main ones has been writes
> to cgroup.procs. cpuset modifications also show up since there's a
> mutex there.
If you can, I'd really like to learn more about the details. We've had some
issues with the threadgroup_rwsem because it's such a big hammer but not
necessarily with cgroup_mutex because they are only used in maintenance
operations and never from any hot paths.
Regarding threadgroup_rwsem, w/ CLONE_INTO_CGROUP (userspace support is
still missing unfortunately), the usual worfklow of creating a cgroup,
seeding it with a process and then later shutting it down doesn't involve
threadgroup_rwsem at all, so most of the problems should go away in the
hopefully near future.
Thanks.
--
tejun
next prev parent reply other threads:[~2022-11-01 19:15 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-26 22:44 [PATCH v2] sched: async unthrottling for cfs bandwidth Josh Don
2022-10-31 13:04 ` Peter Zijlstra
2022-10-31 21:22 ` Josh Don
2022-10-31 21:50 ` Tejun Heo
2022-10-31 23:15 ` Josh Don
2022-10-31 23:53 ` Tejun Heo
2022-11-01 1:01 ` Josh Don
2022-11-01 1:45 ` Tejun Heo
2022-11-01 19:11 ` Josh Don
2022-11-01 19:15 ` Tejun Heo [this message]
2022-11-01 20:56 ` Josh Don
2022-11-01 21:49 ` Tejun Heo
2022-11-01 21:59 ` Josh Don
2022-11-01 22:38 ` Tejun Heo
2022-11-02 17:10 ` Michal Koutný
2022-11-02 17:18 ` Tejun Heo
2022-10-31 21:56 ` Benjamin Segall
2022-11-02 8:40 ` Peter Zijlstra
2022-11-11 0:14 ` Josh Don
2022-11-02 16:59 ` Michal Koutný
2022-11-03 0:10 ` Josh Don
2022-11-03 10:11 ` Michal Koutný
2022-11-16 3:01 ` Josh Don
2022-11-16 9:57 ` Michal Koutný
2022-11-16 21:45 ` Josh Don
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