(2013/01/04 2:54), Michal Hocko wrote: > Now that per-node-zone-priority iterator caches memory cgroups rather > than their css ids we have to be careful and remove them from the > iterator when they are on the way out otherwise they might hang for > unbounded amount of time (until the global/targeted reclaim triggers the > zone under priority to find out the group is dead and let it to find the > final rest). > > This is solved by hooking into mem_cgroup_css_offline and checking all > per-node-zone-priority iterators up the way to the root cgroup. If the > current memcg is found in the respective iter->last_visited then it is > replaced by the previous one in the same sub-hierarchy. > > This guarantees that no group gets more reclaiming than necessary and > the next iteration will continue without noticing that the removed group > has disappeared. > > Spotted-by: Ying Han <yinghan@xxxxxxxxxx> > Signed-off-by: Michal Hocko <mhocko@xxxxxxx> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> -- 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>