From mboxrd@z Thu Jan  1 00:00:00 1970
From: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Subject: Re: [PATCH cgroup/for-3.11 2/3] cgroup: fix RCU accesses around
	task->cgroups
Date: Tue, 25 Jun 2013 11:50:07 -0700
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To: Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Tejun Heo <theo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, Fengguang Wu <fengguang.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org

On Tue, Jun 25, 2013 at 10:02:38AM +0800, Li Zefan wrote:
> > @@ -5046,8 +5049,8 @@ static const struct file_operations proc
> >  void cgroup_fork(struct task_struct *child)
> >  {
> >  	task_lock(current);
> > +	get_css_set(task_css_set(current));
> >  	child->cgroups = current->cgroups;
> 
> While we use RCU_INIT_POINTER() in cgroup_exit(), we don't need to use it here?

Yeap, because both are RCU pointers.  There's no cross (sparse)
address space assignment going on.

Thanks.

-- 
tejun