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Message-ID: <7ff8c948-c5e2-ac5b-6633-8583b8cb75fe@redhat.com>
Date:   Thu, 8 Jun 2023 08:22:06 -0400
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Subject: Re: [PATCH] cgroup/cpuset: Fix comment in cpuset_hotplug_workfn
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To:     suhua <suhua.tanke@gmail.com>, lizefan.x@bytedance.com,
        tj@kernel.org, hannes@cmpxchg.org
Cc:     cgroups@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20230608085439.27501-1-suhua.tanke@gmail.com>
From:   Waiman Long <longman@redhat.com>
In-Reply-To: <20230608085439.27501-1-suhua.tanke@gmail.com>
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On 6/8/23 04:54, suhua wrote:
> "synchronize cpus_allowed to cpu_active_mask"
> -> "synchronize cpu_active_mask to cpus_allowed"
>
> Signed-off-by: suhua <suhua.tanke@gmail.com>
> ---
>   kernel/cgroup/cpuset.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
> index b0aee733b92b..4810d29e2d63 100644
> --- a/kernel/cgroup/cpuset.c
> +++ b/kernel/cgroup/cpuset.c
> @@ -3739,7 +3739,7 @@ static void cpuset_hotplug_workfn(struct work_struct *work)
>   	if (!cpus_updated && top_cpuset.nr_subparts_cpus)
>   		cpus_updated = true;
>   
> -	/* synchronize cpus_allowed to cpu_active_mask */
> +	/* synchronize cpu_active_mask to cpus_allowed */
>   	if (cpus_updated) {
>   		spin_lock_irq(&callback_lock);
>   		if (!on_dfl)

The comment is a bit outdated. The synchronization is only meant for 
cgroup v1, but it is correct in this regard. We are matching 
cpus_allowed of top_cpuset to cpu_active_mask, not the other way around.

Cheers,
Longman