On Wed 17-08-11 21:49:27, Johannes Weiner wrote: > Commit d1a05b6 'memcg: do not try to drain per-cpu caches without > pages' added a drain_local_stock() call to a preemptible section. > > The draining task looks up the cpu-local stock twice to set the > draining-flag, then to drain the stock and clear the flag again. If > the task is migrated to a different CPU in between, noone will clear > the flag on the first stock and it will be forever undrainable. Its > charge can not be recovered and the cgroup can not be deleted anymore. > > Properly pin the task to the executing CPU while draining stocks. > > Signed-off-by: Johannes Weiner <jweiner@xxxxxxxxxx> > Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx > Cc: Michal Hocko <mhocko@xxxxxxx> My fault, I didn't realize that drain_local_stock needs preemption disabled. Sorry about that and good work, Johannes. Acked-by: Michal Hocko <mhocko@xxxxxxx> -- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>