> --- > Subject: vmscan: comment too_many_isolated() > From: Wu Fengguang <fengguang.wu@xxxxxxxxx> > Date: Tue Oct 19 09:53:23 CST 2010 > > Comment "Why it's doing so" rather than "What it does" > as proposed by Andrew Morton. > > Signed-off-by: Wu Fengguang <fengguang.wu@xxxxxxxxx> > --- > mm/vmscan.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > --- linux-next.orig/mm/vmscan.c 2010-10-19 09:29:44.000000000 +0800 > +++ linux-next/mm/vmscan.c 2010-10-19 10:21:41.000000000 +0800 > @@ -1142,7 +1142,11 @@ int isolate_lru_page(struct page *page) > } > > /* > - * Are there way too many processes in the direct reclaim path already? > + * A direct reclaimer may isolate SWAP_CLUSTER_MAX pages from the LRU list and > + * then get resheduled. When there are massive number of tasks doing page > + * allocation, such sleeping direct reclaimers may keep piling up on each CPU, > + * the LRU list will go small and be scanned faster than necessary, leading to > + * unnecessary swapping, thrashing and OOM. > */ > static int too_many_isolated(struct zone *zone, int file, > struct scan_control *sc) nice! Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> -- 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>