commit: 4bf2bba3750f10aa9e62e6949bc7e8329990f01b 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
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]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> --- mm/compaction.c | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-) diff --git a/mm/compaction.c b/mm/compaction.c index 7ea259d..2f42d95 100644 --- 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; + } } - } out: -- 1.7.3.4 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
