On Wed, Aug 31, 2011 at 6:08 PM, Johannes Weiner <jweiner@xxxxxxxxxx> wrote: > Reclaim decides to skip scanning an active list when the corresponding > inactive list is above a certain size in comparison to leave the > assumed working set alone while there are still enough reclaim > candidates around. > > The memcg implementation of comparing those lists instead reports > whether the whole memcg is low on the requested type of inactive > pages, considering all nodes and zones. > > This can lead to an oversized active list not being scanned because of > the state of the other lists in the memcg, as well as an active list > being scanned while its corresponding inactive list has enough pages. > > Not only is this wrong, it's also a scalability hazard, because the > global memory state over all nodes and zones has to be gathered for > each memcg and zone scanned. > > Make these calculations purely based on the size of the two LRU lists > that are actually affected by the outcome of the decision. > > Signed-off-by: Johannes Weiner <jweiner@xxxxxxxxxx> > Cc: Rik van Riel <riel@xxxxxxxxxx> > Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> > Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> > Cc: Daisuke Nishimura <nishimura@xxxxxxxxxxxxxxxxx> > Cc: Balbir Singh <bsingharora@xxxxxxxxx> Reviewed-by: Minchan Kim <minchan.kim@xxxxxxxxx> I can't understand why memcg is designed for considering all nodes and zones. Is it a mistake or on purpose? Maybe Kame or Balbir can answer it. Anyway, this change does make sense to me. Nitpick: Please remove inactive_ratio in Documentation/cgroups/memory.txt. I think it would be better to separate it into another patch. -- Kind regards, Minchan Kim -- 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>