Date:   Thu, 6 Jan 2022 00:35:42 +0000
From:   Wei Yang <richard.weiyang@gmail.com>
To:     Michal Koutn? <mkoutny@suse.com>
Cc:     Wei Yang <richard.weiyang@gmail.com>, tj@kernel.org,
        lizefan.x@bytedance.com, hannes@cmpxchg.org,
        cgroups@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] cgroup/rstat: check updated_next only for root
Message-ID: <20220106003542.d247w7qwtq6ajyii@master>
Reply-To: Wei Yang <richard.weiyang@gmail.com>
References: <20211225000932.7253-1-richard.weiyang@gmail.com>
 <20211225000932.7253-2-richard.weiyang@gmail.com>
 <20220105193504.GD6464@blackbody.suse.cz>
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On Wed, Jan 05, 2022 at 08:35:04PM +0100, Michal Koutn? wrote:
>On Sat, Dec 25, 2021 at 12:09:32AM +0000, Wei Yang <richard.weiyang@gmail.com> wrote:
>> This means we can remove the check on ->updated_next, if we make sure
>> the subtree from @root is on list, which could be done by checking
>> updated_next for root.
>
>Nice refactoring.
>
>> @@ -96,9 +97,12 @@ static struct cgroup *cgroup_rstat_cpu_pop_updated(struct cgroup *pos,
>>  	 * We're gonna walk down to the first leaf and visit/remove it.  We
>>  	 * can pick whatever unvisited node as the starting point.
>>  	 */
>> -	if (!pos)
>> +	if (!pos) {
>>  		pos = root;
>> -	else
>> +		// return NULL if this subtree is not on-list
>> +		if (!cgroup_rstat_cpu(pos, cpu)->updated_next)
>> +			return NULL;
>> +	} else
>+		/* return NULL if this subtree is not on-list */
>
>Just a coding style nitpick.

Thanks for comment. Would you like me to send a v2?

>
>The patch is otherwise
>Reviewed-by: Michal Koutn? <mkoutny@suse.com>

-- 
Wei Yang
Help you, Help me