On Mon, Aug 23, 2010 at 12:31:21AM +0900, Minchan Kim wrote: > <SNIP> > > From 560e8898295c663f02aede07b3d55880eba16c69 Mon Sep 17 00:00:00 2001 > From: Minchan Kim <minchan.kim@xxxxxxxxx> > Date: Mon, 23 Aug 2010 00:20:44 +0900 > Subject: [PATCH] compaction: handle active and inactive fairly in too_many_isolated > > Iram reported compaction's too_many_isolated loops forever. > (http://www.spinics.net/lists/linux-mm/msg08123.html) > > The meminfo of situation happened was inactive anon is zero. > That's because the system has no memory pressure until then. > While all anon pages was in active lru, compaction could select > active lru as well as inactive lru. That's different things > with vmscan's isolated. So we has been two too_many_isolated. > > While compaction can isolated pages in both active and inactive, > current implementation of too_many_isolated only considers inactive. > It made Iram's problem. > > This patch handles active and inactie with fair. > That's because we can't expect where from and how many compaction would > isolated pages. > > This patch changes (nr_isolated > nr_inactive) with > nr_isolated > (nr_active + nr_inactive) / 2. > > Cc: Mel Gorman <mel@xxxxxxxxx> > Cc: Wu Fengguang <fengguang.wu@xxxxxxxxx> > Signed-off-by: Minchan Kim <minchan.kim@xxxxxxxxx> Seems reasonable to me. Acked-by: Mel Gorman <mel@xxxxxxxxx> Want to repost this as a standalone patch? > --- > mm/compaction.c | 9 +++++---- > 1 files changed, 5 insertions(+), 4 deletions(-) > > diff --git a/mm/compaction.c b/mm/compaction.c > index 94cce51..0864839 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -214,15 +214,16 @@ static void acct_isolated(struct zone *zone, struct compact_control *cc) > /* Similar to reclaim, but different enough that they don't share logic */ > static bool too_many_isolated(struct zone *zone) > { > - > - unsigned long inactive, isolated; > + unsigned long active, inactive, isolated; > > inactive = zone_page_state(zone, NR_INACTIVE_FILE) + > zone_page_state(zone, NR_INACTIVE_ANON); > + active = zone_page_state(zone, NR_ACTIVE_FILE) + > + zone_page_state(zone, NR_ACTIVE_ANON); > isolated = zone_page_state(zone, NR_ISOLATED_FILE) + > zone_page_state(zone, NR_ISOLATED_ANON); > - > - return isolated > inactive; > + > + return isolated > (inactive + active) / 2; > } > -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- 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>