[patch] mm, thp: abort compaction if migration page cannot be charged to memcg

David Rientjes
2012-06-21T06:52:40Z

If page migration cannot charge the new 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 in a futile attempt to continue migrations which are only bound to
fail.

This 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 <rientjes@google.com>
---
mm/compaction.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/mm/compaction.c b/mm/compaction.c
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -701,8 +701,11 @@ static int compact_zone(struct zone *zone, struct compact_control *cc)
if (err) {
putback_lru_pages(&cc->migratepages);
cc->nr_migratepages = 0;
+ if (err == -ENOMEM) {
+ ret = COMPACT_PARTIAL;
+ goto out;
+ }
}
-
}