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Date:   Tue, 10 Oct 2023 07:34:08 +0200
From:   Juri Lelli <juri.lelli@redhat.com>
To:     Waiman Long <longman@redhat.com>
Cc:     Tejun Heo <tj@kernel.org>, Zefan Li <lizefan.x@bytedance.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        linux-kernel@vger.kernel.org, cgroups@vger.kernel.org,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@kernel.org>,
        Qais Yousef <qyousef@layalina.io>, Hao Luo <haoluo@google.com>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Xia Fukun <xiafukun@huawei.com>
Subject: Re: [PATCH] cgroup/cpuset: Change nr_deadline_tasks to an atomic_t
 value
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References: <20231009191515.3262292-1-longman@redhat.com>
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Hi,

On 09/10/23 15:15, Waiman Long wrote:
> The nr_deadline_tasks field in cpuset structure was introduced by
> commit 6c24849f5515 ("sched/cpuset: Keep track of SCHED_DEADLINE task
> in cpusets"). Unlike nr_migrate_dl_tasks which is only modified under
> cpuset_mutex, nr_deadline_tasks can be updated in various contexts
> under different locks. As a result, data races may happen that cause
> incorrect value to be stored in nr_deadline_tasks leading to incorrect

Could you please make an example of such data races?

Thanks!
Juri