From: David Rientjes <rientjes@google.com>
To: Wei Yang <richardw.yang@linux.intel.com>
Cc: hannes@cmpxchg.org, mhocko@kernel.org, vdavydov.dev@gmail.com,
akpm@linux-foundation.org, cgroups@vger.kernel.org,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
kirill.shutemov@linux.intel.com, yang.shi@linux.alibaba.com,
alexander.duyck@gmail.com
Subject: Re: [Patch v2] mm: thp: grab the lock before manipulation defer list
Date: Thu, 9 Jan 2020 10:52:01 -0800 (PST) [thread overview]
Message-ID: <alpine.DEB.2.21.2001091051160.57374@chino.kir.corp.google.com> (raw)
In-Reply-To: <20200109143054.13203-1-richardw.yang@linux.intel.com>
On Thu, 9 Jan 2020, Wei Yang wrote:
> As all the other places, we grab the lock before manipulate the defer list.
> Current implementation may face a race condition.
>
> For example, the potential race would be:
>
> CPU1 CPU2
> mem_cgroup_move_account split_huge_page_to_list
> !list_empty
> lock
> !list_empty
> list_del
> unlock
> lock
> # !list_empty might not hold anymore
> list_del_init
> unlock
>
> When this sequence happens, the list_del_init() in
> mem_cgroup_move_account() would crash if CONFIG_DEBUG_LIST since the
> page is already been removed by list_del in split_huge_page_to_list().
>
> Fixes: 87eaceb3faa5 ("mm: thp: make deferred split shrinker memcg aware")
>
> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
> Acked-by: David Rientjes <rientjes@google.com>
Thanks Wei!
Andrew, I'd also suggest:
Cc: stable@vger.kernel.org # 5.4+
next prev parent reply other threads:[~2020-01-09 18:52 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-09 14:30 Wei Yang
2020-01-09 18:52 ` David Rientjes [this message]
2020-01-09 18:58 ` Michal Hocko
2020-01-11 0:03 ` Kirill A. Shutemov
2020-01-12 2:28 ` Wei Yang
2020-01-12 22:57 ` Kirill A. Shutemov
2020-01-13 0:44 ` Wei Yang
2020-01-13 7:36 ` Kirill A. Shutemov
2020-01-13 8:23 ` Wei Yang
2020-01-14 9:31 ` Michal Hocko
2020-01-14 10:31 ` Kirill A. Shutemov
2020-01-14 10:59 ` Kirill A. Shutemov
2020-01-14 20:57 ` David Rientjes
2020-01-15 1:19 ` Wei Yang
2020-01-15 1:07 ` Wei Yang
2020-01-15 3:26 ` David Rientjes
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