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Date: Wed, 21 Dec 2011 09:53:08 +0800
From: Li Zefan <lizf@cn.fujitsu.com>
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To: Frederic Weisbecker <fweisbec@gmail.com>
CC: Tejun Heo <tj@kernel.org>, LKML <linux-kernel@vger.kernel.org>,
        Containers <containers@lists.linux-foundation.org>,
        Cgroups <cgroups@vger.kernel.org>,
        KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
        Oleg Nesterov <oleg@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Paul Menage <paul@paulmenage.org>,
        Mandeep Singh Baines <msb@chromium.org>
Subject: Re: [PATCH 1/2] cgroup: Remove unnecessary task_lock before fetching
 css_set on migration
References: <1324320274-18485-1-git-send-email-msb@chromium.org> <1324407673-18975-1-git-send-email-fweisbec@gmail.com>
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Frederic Weisbecker wrote:
> When we fetch the css_set of the tasks on cgroup migration, we don't need
> anymore to synchronize against cgroup_exit() that could swap the old one
> with init_css_set. Now that we are using threadgroup_lock() during
> the migrations, we don't need to worry about it anymore.
> 
> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

Good catch!

Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>

> Cc: Tejun Heo <tj@kernel.org>
> Cc: Li Zefan <lizf@cn.fujitsu.com>
> Cc: Containers <containers@lists.linux-foundation.org>
> Cc: Cgroups <cgroups@vger.kernel.org>
> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> Cc: Oleg Nesterov <oleg@redhat.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Paul Menage <paul@paulmenage.org>
> Cc: Mandeep Singh Baines <msb@chromium.org>
> ---
>  kernel/cgroup.c |   21 +++++++++++----------
>  1 files changed, 11 insertions(+), 10 deletions(-)