Message-ID: <699b3962-1b9e-ab76-8dd4-13311fb2c0c9@google.com>
Date:   Thu, 6 Jan 2022 11:43:12 -0500
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Subject: Re: [PATCH v2 3/3] prlimit: do not grab the tasklist_lock
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To:     "Eric W. Biederman" <ebiederm@xmission.com>
Cc:     Christian Brauner <christian.brauner@ubuntu.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Alexey Gladkov <legion@kernel.org>,
        William Cohen <wcohen@redhat.com>,
        Viresh Kumar <viresh.kumar@linaro.org>,
        Alexey Dobriyan <adobriyan@gmail.com>,
        Chris Hyser <chris.hyser@oracle.com>,
        Peter Collingbourne <pcc@google.com>,
        Xiaofeng Cao <caoxiaofeng@yulong.com>,
        David Hildenbrand <david@redhat.com>,
        Cyrill Gorcunov <gorcunov@gmail.com>,
        linux-kernel@vger.kernel.org
References: <20220105212828.197013-1-brho@google.com>
 <20220105212828.197013-4-brho@google.com>
 <874k6h7s8o.fsf@email.froward.int.ebiederm.org>
From:   Barret Rhoden <brho@google.com>
In-Reply-To: <874k6h7s8o.fsf@email.froward.int.ebiederm.org>
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On 1/5/22 17:05, Eric W. Biederman wrote:
> 
> I think the simple solution is just:
> 	update_rlimit_cpu(tsk->group_leader)
> 
> As the group leader is guaranteed to be the last thread of the thread
> group to be processed in release_task, and thus the last thread with a
> sighand.  Nothing needs to be done if it does not have a sighand.

Ah, good to know.  I didn't know the group_leader stuck around as a 
zombie.  That makes life easier.  I'll make the change and repost the 
patches.

Thanks,

Barret