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Sender: Tejun Heo <htejun@gmail.com>
Date: Wed, 17 Apr 2024 16:02:14 -1000
From: Tejun Heo <tj@kernel.org>
To: Xiu Jianfeng <xiujianfeng@huaweicloud.com>
Cc: lizefan.x@bytedance.com, hannes@cmpxchg.org, cgroups@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH -next] cgroup: don't call cgroup1_pidlist_destroy_all()
 for v2
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References: <20240417021359.883736-1-xiujianfeng@huaweicloud.com>
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In-Reply-To: <20240417021359.883736-1-xiujianfeng@huaweicloud.com>

Hello,

On Wed, Apr 17, 2024 at 02:13:59AM +0000, Xiu Jianfeng wrote:
> From: Xiu Jianfeng <xiujianfeng@huawei.com>
> 
> Currently cgroup1_pidlist_destroy_all() will be called when releasing
> cgroup even if the cgroup is on default hierarchy, however it doesn't
> make any sense for v2 to destroy pidlist of v1.
> 
> Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
> ---
>  kernel/cgroup/cgroup-v1.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
> index 520a11cb12f4..46d89157d558 100644
> --- a/kernel/cgroup/cgroup-v1.c
> +++ b/kernel/cgroup/cgroup-v1.c
> @@ -197,6 +197,8 @@ void cgroup1_pidlist_destroy_all(struct cgroup *cgrp)
>  {
>  	struct cgroup_pidlist *l, *tmp_l;
>  
> +	if (cgroup_on_dfl(cgrp))
> +		return;

Can you move the test to the caller?

Thanks.

-- 
tejun