Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Tue, 13 Jul 2021 11:32:29 +0200
From:   Michal Hocko <mhocko@suse.com>
To:     Miaohe Lin <linmiaohe@huawei.com>
Cc:     akpm@linux-foundation.org, hannes@cmpxchg.org, vbabka@suse.cz,
        axboe@kernel.dk, iamjoonsoo.kim@lge.com, alexs@kernel.org,
        apopple@nvidia.com, willy@infradead.org, minchan@kernel.org,
        david@redhat.com, shli@fb.com, hillf.zj@alibaba-inc.com,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 5/5] mm/vmscan: fix misleading comment in
 isolate_lru_pages()
Message-ID: <YO1drWweAjSz8Oa+@dhcp22.suse.cz>
References: <20210710100329.49174-1-linmiaohe@huawei.com>
 <20210710100329.49174-6-linmiaohe@huawei.com>
 <YOvvFaYMBhISeGEI@dhcp22.suse.cz>
 <ed30bbc5-8438-d399-a9ef-462eda1b6d4e@huawei.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <ed30bbc5-8438-d399-a9ef-462eda1b6d4e@huawei.com>
Precedence: bulk

On Mon 12-07-21 19:16:47, Miaohe Lin wrote:
> On 2021/7/12 15:28, Michal Hocko wrote:
> > On Sat 10-07-21 18:03:29, Miaohe Lin wrote:
> >> We couldn't know whether the page is being freed elsewhere until we failed
> >> to increase the page count.
> > 
> > This is moving a hard to understand comment from one place to another.
> 
> If get_page_unless_zero failed, the page could have been freed elsewhere. I think
> this looks straightforward but doesn't help a lot. Are you preferring to just
> remove this comment ?

Yes the comment in its current form is not really helpful much. Does it
deserve a single liner to drop it? Likely not on its own without more
changes in that area.
-- 
Michal Hocko
SUSE Labs