On Mon, 27 Sep 2010 11:04:54 +0900 (JST) KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> wrote: > > On Thu, 16 Sep 2010 19:01:32 +0900 (JST) > > KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> wrote: > > > > > Yes, sadly intel motherboard turn on zone_reclaim_mode by default. and > > > current zone_reclaim_mode doesn't fit file/web server usecase ;-) > > > > > > So, I've created new proof concept patch. This doesn't disable zone_reclaim > > > at all. Instead, distinguish for file cache and for anon allocation and > > > only file cache doesn't use zone-reclaim. > > > > > > That said, high-end hpc user often turn on cpuset.memory_spread_page and > > > they avoid this issue. But, why don't we consider avoid it by default? > > > > > > > > > Rob, I wonder if following patch help you. Could you please try it? > > > > > > > > > Subject: [RFC] vmscan: file cache doesn't use zone_reclaim by default > > > > > > > Hm, can't we use migration of file caches rather than pageout in > > zone_reclaim_mode ? Doent' it fix anything ? > > Doesn't. > > Two problem. 1) Migration makes copy. then it's slower than zone_reclaim=0 > 2) Migration is only effective if target node has much free pages. but it > is not generic assumption. > > For this case, zone_reclaim_mode=0 is best. my patch works as second best. > your one works as third. > Hmm. I'm not sure whether it's "slower" or not. And Migraion doesn't assume target node because it can use zonelist fallback. I'm just has concerns that kicked-out pages will be paged-in soon. But ok, maybe complicated. Thanks, -Kame -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>