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Date:   Thu, 1 Apr 2021 16:37:29 +0200
From:   Michal Hocko <mhocko@suse.com>
To:     Muchun Song <songmuchun@bytedance.com>
Cc:     Alexander Viro <viro@zeniv.linux.org.uk>,
        Tejun Heo <tj@kernel.org>, axboe@fb.com,
        Matthew Wilcox <willy@infradead.org>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: [External] Re: [PATCH v2] writeback: fix obtain a reference to a
 freeing memcg css
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On Thu 01-04-21 21:59:13, Muchun Song wrote:
> On Thu, Apr 1, 2021 at 6:26 PM Michal Hocko <mhocko@suse.com> wrote:
[...]
> > Even if the css ref count is not really necessary it shouldn't cause any
> > harm and it makes the code easier to understand. At least a comment
> > explaining why that is not necessary would be required without it
> 
> OK. I will add a comment here to explain why we need to hold a
> ref.

I do not think this is necessary. Taking the reference is a standard
way and I am not sure it requires a comment. I meant to say that not
having a reference should really have a comment explaining why.

Thanks!
-- 
Michal Hocko
SUSE Labs