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Date: Thu, 18 Apr 2024 10:11:08 +0800
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Subject: Re: [PATCH -next] cgroup: don't call cgroup1_pidlist_destroy_all()
 for v2
To: Tejun Heo <tj@kernel.org>, Xiu Jianfeng <xiujianfeng@huaweicloud.com>
CC: <lizefan.x@bytedance.com>, <hannes@cmpxchg.org>,
	<cgroups@vger.kernel.org>, <linux-kernel@vger.kernel.org>
References: <20240417021359.883736-1-xiujianfeng@huaweicloud.com>
 <ZiB_Jhj2I8YdYs64@slm.duckdns.org>
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From: xiujianfeng <xiujianfeng@huawei.com>
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Hi,

On 2024/4/18 10:02, Tejun Heo wrote:
> 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?

Sure, will do in v2.

> 
> Thanks.
>