[Devel] Re: [PATCH v2 3/5] change number_of_cpusets to an atomic

[KAMEZAWA Hiroyuki]

(2012/04/24 4:37), Glauber Costa wrote:

> This will allow us to call destroy() without holding the
> cgroup_mutex(). Other important updates inside update_flags()
> are protected by the callback_mutex.
> 
> We could protect this variable with the callback_mutex as well,
> as suggested by Li Zefan, but we need to make sure we are protected
> by that mutex at all times, and some of its updates happen inside the
> cgroup_mutex - which means we would deadlock.
> 
> An atomic variable is not expensive, since it is seldom updated,
> and protect us well.
> 
> Signed-off-by: Glauber Costa <glommer at parallels.com>


Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu at jp.fujitsu.com>