On Fri, Jan 22, 2016 at 04:50:42PM +0300, Vladimir Davydov wrote: > From first glance, it looks like the bug was triggered, because > mem_cgroup_css_offline was run for a child cgroup earlier than for its > parent. This couldn't happen for sure before the cgroup was switched to > percpu_ref, because cgroup_destroy_wq has always had max_active == 1. > Now, however, it looks like this is perfectly possible for > css_killed_ref_fn is called from an rcu callback - see kill_css -> > percpu_ref_kill_and_confirm. This breaks kmemcg assumptions. > > I'll take a look what can be done about that. It's an acknowledged problem in the cgroup core then, and not an issue with kmemcg. Tejun sent a fix to correct the offlining order here: https://www.mail-archive.com/linux-kernel@xxxxxxxxxxxxxxx/msg1056544.html -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>