The patch titled
oom: reclaim_mapped on oom
has been removed from the -mm tree. Its filename is
oom-reclaim_mapped-on-oom.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: oom: reclaim_mapped on oom
From: Nick Piggin <npiggin@xxxxxxx>
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@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
mm/vmscan.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff -puN mm/vmscan.c~oom-reclaim_mapped-on-oom mm/vmscan.c
--- a/mm/vmscan.c~oom-reclaim_mapped-on-oom
+++ a/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 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
* 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
_
Patches currently in -mm which might be from npiggin@xxxxxxx are
origin.patch
git-block.patch
page-invalidation-cleanup.patch
mm-micro-optimise-zone_watermark_ok.patch
radix-tree-rcu-lockless-readside.patch
select_bad_process-cleanup-releasing-check.patch
oom-dont-kill-current-when-another-oom-in-progress.patch
sched-force-sbin-init-off-isolated-cpus.patch
-
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