From mboxrd@z Thu Jan  1 00:00:00 1970
From: Li Zefan <lizefan@huawei.com>
Subject: Re: [PATCH] memcg: don't do cleanup manually if mem_cgroup_css_online()
 fails
Date: Tue, 2 Apr 2013 16:03:57 +0800
Message-ID: <515A90ED.7010208@huawei.com>
References: <515A8A40.6020406@huawei.com>
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To: Michal Hocko <mhocko@suse.cz>
Cc: Glauber Costa <glommer@parallels.com>, Johannes Weiner <hannes@cmpxchg.org>, KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>, LKML <linux-kernel@vger.kernel.org>, Cgroups <cgroups@vger.kernel.org>, linux-mm@kvack.org

On 2013/4/2 15:35, Li Zefan wrote:
> If memcg_init_kmem() returns -errno when a memcg is being created,
> mem_cgroup_css_online() will decrement memcg and its parent's refcnt,

> (but strangely there's no mem_cgroup_put() for mem_cgroup_get() called
> in memcg_propagate_kmem()).

The comment in memcg_propagate_kmem() suggests it knows mem_cgroup_css_free()
will be called in failure, while mem_cgroup_css_online() doesn't know.

> 
> But then cgroup core will call mem_cgroup_css_free() to do cleanup...
> 
> Signed-off-by: Li Zefan <lizefan@huawei.com>
> ---
>  mm/memcontrol.c | 11 +----------
>  1 file changed, 1 insertion(+), 10 deletions(-)