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authorNick Piggin <npiggin@suse.de>2006-09-25 23:31:28 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-09-26 08:48:48 -0700
commit4ff1ffb4870b007b86f21e5f27eeb11498c4c077 (patch)
treef168408f90214873e1fa36733d29f2ba002fae46
parent408d85441cd5a9bd6bc851d677a10c605ed8db5f (diff)
[PATCH] oom: reclaim_mapped on oom
Potentially it takes several scans of the lru lists before we can even start reclaiming pages. mapped pages, with young ptes can take 2 passes on the active list + one on the inactive list. But reclaim_mapped may not always kick in instantly, so it could take even more than that. Raise the threshold for marking a zone as all_unreclaimable from a factor of 4 time the pages in the zone to 6. Introduce a mechanism to force reclaim_mapped if we've reached a factor 3 and still haven't made progress. Previously, a customer doing stress testing was able to easily OOM the box after using only a small fraction of its swap (~100MB). After the patches, it would only OOM after having used up all swap (~800MB). Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--mm/vmscan.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c
index ba18d0c36b8..8f35d7d585c 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -697,6 +697,11 @@ done:
return nr_reclaimed;
}
+static inline int zone_is_near_oom(struct zone *zone)
+{
+ return zone->pages_scanned >= (zone->nr_active + zone->nr_inactive)*3;
+}
+
/*
* This moves pages from the active list to the inactive list.
*
@@ -732,6 +737,9 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
long distress;
long swap_tendency;
+ if (zone_is_near_oom(zone))
+ goto force_reclaim_mapped;
+
/*
* `distress' is a measure of how much trouble we're having
* reclaiming pages. 0 -> no problems. 100 -> great trouble.
@@ -767,6 +775,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
* memory onto the inactive list.
*/
if (swap_tendency >= 100)
+force_reclaim_mapped:
reclaim_mapped = 1;
}
@@ -1161,7 +1170,7 @@ scan:
if (zone->all_unreclaimable)
continue;
if (nr_slab == 0 && zone->pages_scanned >=
- (zone->nr_active + zone->nr_inactive) * 4)
+ (zone->nr_active + zone->nr_inactive) * 6)
zone->all_unreclaimable = 1;
/*
* If we've done a decent amount of scanning and