On Mon 01-08-11 16:37:45, Michal Hocko wrote: > On Wed 27-07-11 14:49:00, KAMEZAWA Hiroyuki wrote: > > memcg :avoid node fallback scan if possible. > > > > Now, try_to_free_pages() scans all zonelist because the page allocator > > should visit all zonelists...but that behavior is harmful for memcg. > > Memcg just scans memory because it hits limit...no memory shortage > > in pased zonelist. > > > > For example, with following unbalanced nodes > > > > Node 0 Node 1 > > File 1G 0 > > Anon 200M 200M > > > > memcg will cause swap-out from Node1 at every vmscan. > > > > Another example, assume 1024 nodes system. > > With 1024 node system, memcg will visit 1024 nodes > > pages per vmscan... This is overkilling. > > > > This is why memcg's victim node selection logic doesn't work > > as expected. > > Previous patch adds nodemask filled by > mem_cgroup_select_victim_node. Shouldn't we rather limit that nodemask > to a victim node? Bahh, scratch that. I was jumping from one thing to another and got totally confused. Victim memcg is not bound to any particular node in general... Sorry for noise. I will try to get back to this tomorrow. -- 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>