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Message-ID: <6599ad830804222348u2b3b6e8coc753fd798c750e26@mail.gmail.com>
Date: Tue, 22 Apr 2008 23:48:28 -0700
From: "Paul Menage" <menage@google.com>
To: "Li Zefan" <lizf@cn.fujitsu.com>
Subject: Re: [PATCH] cgroup: use read lock to guard find_existing_css_set()
Cc: "Andrew Morton" <akpm@linux-foundation.org>,
       LKML <linux-kernel@vger.kernel.org>,
       "Linux Containers" <containers@lists.linux-foundation.org>
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On Tue, Apr 22, 2008 at 8:04 PM, Li Zefan <lizf@cn.fujitsu.com> wrote:
> The function does not modify anything (except the temporary
>  css template), so it's sufficient to hold read lock.
>
>  Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>

Acked-by: Paul Menage <menage@google.com>

Thanks.

>  ---
>   kernel/cgroup.c |    4 ++--
>   1 files changed, 2 insertions(+), 2 deletions(-)
>
>  diff --git a/kernel/cgroup.c b/kernel/cgroup.c
>  index 2727f92..e9eb5da 100644
>  --- a/kernel/cgroup.c
>  +++ b/kernel/cgroup.c
>  @@ -406,11 +406,11 @@ static struct css_set *find_css_set(
>
>         /* First see if we already have a cgroup group that matches
>          * the desired set */
>  -       write_lock(&css_set_lock);
>  +       read_lock(&css_set_lock);
>         res = find_existing_css_set(oldcg, cgrp, template);
>         if (res)
>                 get_css_set(res);
>  -       write_unlock(&css_set_lock);
>  +       read_unlock(&css_set_lock);
>
>         if (res)
>                 return res;
>  -- 1.5.4.rc3
>
>