Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Thu, 6 Apr 2023 11:45:53 +0200
From:   Christian Brauner <brauner@kernel.org>
To:     Waiman Long <longman@redhat.com>
Cc:     Tejun Heo <tj@kernel.org>, Zefan Li <lizefan.x@bytedance.com>,
        Johannes Weiner <hannes@cmpxchg.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 1/3] cgroup/cpuset: Make cpuset_fork() handle
 CLONE_INTO_CGROUP properly
Message-ID: <20230406-vernommen-kurieren-e75f4ee6ea96@brauner>
References: <20230331145045.2251683-1-longman@redhat.com>
 <20230331145045.2251683-2-longman@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <20230331145045.2251683-2-longman@redhat.com>
Precedence: bulk

On Fri, Mar 31, 2023 at 10:50:43AM -0400, Waiman Long wrote:
> By default, the clone(2) syscall spawn a child process into the same
> cgroup as its parent. With the use of the CLONE_INTO_CGROUP flag
> introduced by commit ef2c41cf38a7 ("clone3: allow spawning processes
> into cgroups"), the child will be spawned into a different cgroup which
> is somewhat similar to writing the child's tid into "cgroup.threads".
> 
> The current cpuset_fork() method does not properly handle the
> CLONE_INTO_CGROUP case where the cpuset of the child may be different
> from that of its parent.  Update the cpuset_fork() method to treat the
> CLONE_INTO_CGROUP case similar to cpuset_attach().
> 
> Since the newly cloned task has not been running yet, its actual
> memory usage isn't known. So it is not necessary to make change to mm
> in cpuset_fork().
> 
> Fixes: ef2c41cf38a7 ("clone3: allow spawning processes into cgroups")
> Signed-off-by: Waiman Long <longman@redhat.com>
> ---

Just two nits. I think this needs a Cc stable and it would be nice if
you could give Giuseppe a "Reported-by".