From: Andrew Morton <akpm@linux-foundation.org>
To: Wei Yang <richardw.yang@linux.intel.com>
Cc: hannes@cmpxchg.org, mhocko@kernel.org, vdavydov.dev@gmail.com,
ktkhai@virtuozzo.com, kirill.shutemov@linux.intel.com,
yang.shi@linux.alibaba.com, cgroups@vger.kernel.org,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
alexander.duyck@gmail.com, rientjes@google.com,
stable@vger.kernel.org
Subject: Re: [Patch v4] mm: thp: remove the defer list related code since this will not happen
Date: Sat, 18 Jan 2020 14:54:21 -0800 [thread overview]
Message-ID: <20200118145421.0ab96d5d9bea21a3339d52fe@linux-foundation.org> (raw)
In-Reply-To: <20200117233836.3434-1-richardw.yang@linux.intel.com>
On Sat, 18 Jan 2020 07:38:36 +0800 Wei Yang <richardw.yang@linux.intel.com> wrote:
> If compound is true, this means it is a PMD mapped THP. Which implies
> the page is not linked to any defer list. So the first code chunk will
> not be executed.
>
> Also with this reason, it would not be proper to add this page to a
> defer list. So the second code chunk is not correct.
>
> Based on this, we should remove the defer list related code.
>
> Fixes: 87eaceb3faa5 ("mm: thp: make deferred split shrinker memcg aware")
>
> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
> Suggested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Cc: <stable@vger.kernel.org> [5.4+]
This patch is identical to "mm: thp: grab the lock before manipulating
defer list", which is rather confusing. Please let people know when
this sort of thing is done.
The earlier changelog mentioned a possible race condition. This
changelog does not. In fact this changelog fails to provide any
description of any userspace-visible runtime effects of the bug.
Please send along such a description for inclusion, as always.
next prev parent reply other threads:[~2020-01-18 22:54 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-17 23:38 [Patch v4] mm: thp: remove the defer list related code since this will not happen Wei Yang
2020-01-18 0:57 ` Yang Shi
2020-01-18 5:30 ` Yang Shi
2020-01-18 22:54 ` Andrew Morton [this message]
2020-01-18 23:36 ` David Rientjes
2020-01-19 2:24 ` Wei Yang
2020-01-20 7:22 ` Michal Hocko
2020-01-20 8:17 ` Wei Yang
2020-01-20 21:10 ` David Rientjes
2020-01-20 21:27 ` Michal Hocko
2020-01-21 23:08 ` David Rientjes
2020-01-22 8:14 ` Michal Hocko
2020-01-22 23:39 ` David Rientjes
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