From: Tejun Heo <tj@kernel.org>
To: Joel Savitz <jsavitz@redhat.com>
Cc: linux-kernel@vger.kernel.org, "Li Zefan" <lizefan@huawei.com>,
"Phil Auld" <pauld@redhat.com>,
"Waiman Long" <longman@redhat.com>,
"Michal Koutný" <mkoutny@suse.com>,
"Ingo Molnar" <mingo@redhat.com>,
"Peter Zijlstra" <peterz@infradead.org>,
cgroups@vger.kernel.org
Subject: Re: [RESEND PATCH v3] cpuset: restore sanity to cpuset_cpus_allowed_fallback()
Date: Wed, 12 Jun 2019 11:02:36 -0700 [thread overview]
Message-ID: <20190612180236.GQ3341036@devbig004.ftw2.facebook.com> (raw)
In-Reply-To: <1560354648-23632-1-git-send-email-jsavitz@redhat.com>
On Wed, Jun 12, 2019 at 11:50:48AM -0400, Joel Savitz wrote:
> In the case that a process is constrained by taskset(1) (i.e.
> sched_setaffinity(2)) to a subset of available cpus, and all of those are
> subsequently offlined, the scheduler will set tsk->cpus_allowed to
> the current value of task_cs(tsk)->effective_cpus.
>
> This is done via a call to do_set_cpus_allowed() in the context of
> cpuset_cpus_allowed_fallback() made by the scheduler when this case is
> detected. This is the only call made to cpuset_cpus_allowed_fallback()
> in the latest mainline kernel.
>
> However, this is not sane behavior.
...
> Suggested-by: Waiman Long <longman@redhat.com>
> Suggested-by: Phil Auld <pauld@redhat.com>
> Signed-off-by: Joel Savitz <jsavitz@redhat.com>
Applied to cgroup/for-5.2-fixes.
Thanks.
--
tejun
prev parent reply other threads:[~2019-06-12 18:02 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-12 15:50 [RESEND PATCH v3] cpuset: restore sanity to cpuset_cpus_allowed_fallback() Joel Savitz
2019-06-12 16:02 ` Tejun Heo
2019-06-12 17:39 ` Peter Zijlstra
2019-06-12 16:31 ` Waiman Long
2019-06-12 17:30 ` Phil Auld
2019-06-12 18:02 ` Tejun Heo [this message]
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