On Thu 26-05-16 14:02:02, Andrew Morton wrote: > On Thu, 26 May 2016 16:30:18 -0400 Tejun Heo <tj@xxxxxxxxxx> wrote: > > > memcg_offline_kmem() may be called from memcg_free_kmem() after a css > > init failure. memcg_free_kmem() is a ->css_free callback which is > > called without cgroup_mutex and memcg_offline_kmem() ends up using > > css_for_each_descendant_pre() without any locking. Fix it by adding > > rcu read locking around it. > > > > mkdir: cannot create directory ___65530___: No space left on device > > [ 527.241361] =============================== > > [ 527.241845] [ INFO: suspicious RCU usage. ] > > [ 527.242367] 4.6.0-work+ #321 Not tainted > > [ 527.242730] ------------------------------- > > [ 527.243220] kernel/cgroup.c:4008 cgroup_mutex or RCU read lock required! > > cc:stable? Also which kernel versions would be affected? I have tried to look and got lost in the indirection of the css_free path. Thanks! -- Michal Hocko SUSE Labs -- 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>