On Wed, Mar 16, 2016 at 06:04:56PM +0100, Peter Zijlstra wrote:
> > Hmmm... I don't think it'd be safe to merge the two ops. Nothing
> > guarantees that the RCU callback of cpu controller is called after the
> > cgroup core one and cgroup core one would do use-after-free. Just
> > changing offline to released should do.
>
> I'm confused, the code looks like:
>
> static void cpu_cgroup_css_released(struct cgroup_subsys_state *css)
> {
> struct task_group *tg = css_tg(css);
>
> sched_offline_group(tg);
> }
>
> static void cpu_cgroup_css_free(struct cgroup_subsys_state *css)
> {
> struct task_group *tg = css_tg(css);
>
> /*
> * Relies on the RCU grace period between css_release() and this.
> */
> sched_free_group(tg);
> }
Oops, misread the two functions swapping positions as getting merged.
Yes, that is correct. Sorry about the confusion. Please feel free to
add
Acked-by: Tejun Heo <t...@kernel.org>
Thanks.
--
tejun
