On Mon, Dec 03, 2018 at 08:17:06AM -0800, Tejun Heo wrote: > On Fri, Nov 30, 2018 at 03:47:41PM -0800, Roman Gushchin wrote: > > + * nr_descendants and nr_dying_descendants are protected > > + * by cgroup_mutex and css_set_lock. > > Can you be a bit more specific - hold both for writes, either for > reads. Sure. Thanks!