From: Waiman Long <longman@redhat.com>
To: "Michal Koutný" <mkoutny@suse.com>
Cc: Tejun Heo <tj@kernel.org>, Zefan Li <lizefan.x@bytedance.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Christian Brauner <brauner@kernel.org>,
cgroups@vger.kernel.org, linux-kernel@vger.kernel.org,
Juri Lelli <juri.lelli@redhat.com>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
gscrivan@redhat.com
Subject: Re: [PATCH 3/3] cgroup/cpuset: Allow only one active attach operation per cpuset
Date: Tue, 4 Apr 2023 10:12:48 -0400 [thread overview]
Message-ID: <db9689cb-7d2b-8a76-06f4-271134dd1bfb@redhat.com> (raw)
In-Reply-To: <20230404090737.3g3uxga52bojgdu5@blackpad>
On 4/4/23 05:07, Michal Koutný wrote:
> Hi.
>
> On Mon, Apr 03, 2023 at 01:41:33PM -0400, Waiman Long <longman@redhat.com> wrote:
>> This patch is actually not related to the CLONE_INTO_GROUP problem in patch
>> 1. It is a generic problem when multiple users are moving threads into
>> cgroup.threads of the same or different cpusets simultaneously.
> I meant this:
> __cgroup_procs_write
> cgroup_kn_lock_live
> mutex_lock(&cgroup_mutex)
>
> and (more succintly)
> cgroup_update_dfl_csses
> lockdep_assert_held(&cgroup_mutex)
>
> Even the threaded migrations should be synchronized here.
> Can you please explain in more detail what's the problematic case?
You are right. I missed the cgroup_mutex synchronization here. So this
patch isn't needed. I will drop it in the next version.
Cheers,
Longman
next prev parent reply other threads:[~2023-04-04 14:14 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-31 14:50 [PATCH 0/3] cgroup/cpuset: Fix CLONE_INTO_CGROUP problem & other issues Waiman Long
2023-03-31 14:50 ` [PATCH 1/3] cgroup/cpuset: Make cpuset_fork() handle CLONE_INTO_CGROUP properly Waiman Long
2023-04-03 16:55 ` Michal Koutný
2023-04-03 17:18 ` Waiman Long
2023-04-03 17:29 ` Waiman Long
2023-04-04 9:19 ` Michal Koutný
2023-04-04 13:52 ` Waiman Long
2023-04-04 17:26 ` Waiman Long
2023-04-06 2:51 ` kernel test robot
2023-04-06 12:17 ` Waiman Long
2023-04-06 9:45 ` Christian Brauner
2023-04-06 14:08 ` Waiman Long
2023-03-31 14:50 ` [PATCH 2/3] cgroup/cpuset: Make cpuset_attach_task() skip subpartitions CPUs for top_cpuset Waiman Long
2023-04-03 16:35 ` Michal Koutný
2023-03-31 14:50 ` [PATCH 3/3] cgroup/cpuset: Allow only one active attach operation per cpuset Waiman Long
2023-04-03 16:47 ` Michal Koutný
2023-04-03 17:41 ` Waiman Long
2023-04-04 9:07 ` Michal Koutný
2023-04-04 14:12 ` Waiman Long [this message]
2023-04-06 9:44 ` Christian Brauner
2023-04-07 15:30 ` Waiman Long
2023-04-09 11:46 ` Christian Brauner
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