This is a note to let you know that I've just added the patch titled
mm, thp: abort compaction if migration page cannot be charged to memcg
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mm-thp-abort-compaction-if-migration-page-cannot-be-charged-to-memcg.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 4bf2bba3750f10aa9e62e6949bc7e8329990f01b Mon Sep 17 00:00:00 2001
From: David Rientjes <[email protected]>
Date: Wed, 11 Jul 2012 14:02:13 -0700
Subject: mm, thp: abort compaction if migration page cannot be charged to memcg
From: David Rientjes <[email protected]>
commit 4bf2bba3750f10aa9e62e6949bc7e8329990f01b upstream.
If page migration cannot charge the temporary page to the memcg,
migrate_pages() will return -ENOMEM. This isn't considered in memory
compaction however, and the loop continues to iterate over all
pageblocks trying to isolate and migrate pages. If a small number of
very large memcgs happen to be oom, however, these attempts will mostly
be futile leading to an enormous amout of cpu consumption due to the
page migration failures.
This patch will short circuit and fail memory compaction if
migrate_pages() returns -ENOMEM. COMPACT_PARTIAL is returned in case
some migrations were successful so that the page allocator will retry.
Signed-off-by: David Rientjes <[email protected]>
Acked-by: Mel Gorman <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Kamezawa Hiroyuki <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
mm/compaction.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -594,8 +594,11 @@ static int compact_zone(struct zone *zon
if (err) {
putback_lru_pages(&cc->migratepages);
cc->nr_migratepages = 0;
+ if (err == -ENOMEM) {
+ ret = COMPACT_PARTIAL;
+ goto out;
+ }
}
-
}
out:
Patches currently in stable-queue which might be from [email protected] are
queue-3.4/memory-hotplug-fix-invalid-memory-access-caused-by-stale-kswapd-pointer.patch
queue-3.4/mm-thp-abort-compaction-if-migration-page-cannot-be-charged-to-memcg.patch
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