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Message-ID: <5159151E.9070204@jp.fujitsu.com>
Date: Mon, 01 Apr 2013 14:03:26 +0900
From: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
MIME-Version: 1.0
Subject: Re: [PATCH] memcg: take reference before releasing rcu_read_lock
References: <51556CE9.9060000@huawei.com>
In-Reply-To: <51556CE9.9060000@huawei.com>
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Sender: owner-linux-mm@kvack.org
List-ID: <linux-mm.kvack.org>
To: Li Zefan <lizefan@huawei.com>
Cc: Glauber Costa <glommer@parallels.com>, Michal Hocko <mhocko@suse.cz>, Johannes Weiner <hannes@cmpxchg.org>, LKML <linux-kernel@vger.kernel.org>, Cgroups <cgroups@vger.kernel.org>, linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>

(2013/03/29 19:28), Li Zefan wrote:
> The memcg is not referenced, so it can be destroyed at anytime right
> after we exit rcu read section, so it's not safe to access it.
> 
> To fix this, we call css_tryget() to get a reference while we're still
> in rcu read section.
> 
> This also removes a bogus comment above __memcg_create_cache_enqueue().
> 
> Signed-off-by: Li Zefan <lizefan@huawei.com>

Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>


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