From c8f7de0bfae36e8532e5e25a39d15407f02aca78 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Fri, 20 May 2016 16:56:47 -0700 Subject: mm, compaction: distinguish between full and partial COMPACT_COMPLETE COMPACT_COMPLETE now means that compaction and free scanner met. This is not very useful information if somebody just wants to use this feedback and make any decisions based on that. The current caller might be a poor guy who just happened to scan tiny portion of the zone and that could be the reason no suitable pages were compacted. Make sure we distinguish the full and partial zone walks. Consumers should treat COMPACT_PARTIAL_SKIPPED as a potential success and be optimistic in retrying. The existing users of COMPACT_COMPLETE are conservatively changed to use COMPACT_PARTIAL_SKIPPED as well but some of them should be probably reconsidered and only defer the compaction only for COMPACT_COMPLETE with the new semantic. This patch shouldn't introduce any functional changes. Signed-off-by: Michal Hocko Acked-by: Vlastimil Babka Acked-by: Hillf Danton Cc: David Rientjes Cc: Johannes Weiner Cc: Joonsoo Kim Cc: Mel Gorman Cc: Tetsuo Handa Cc: Vladimir Davydov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/compaction.h | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'include/linux/compaction.h') diff --git a/include/linux/compaction.h b/include/linux/compaction.h index 11f228712ed5..9b37f9d3f7a8 100644 --- a/include/linux/compaction.h +++ b/include/linux/compaction.h @@ -21,7 +21,15 @@ enum compact_result { * pages */ COMPACT_PARTIAL, - /* The full zone was compacted */ + /* + * direct compaction has scanned part of the zone but wasn't successfull + * to compact suitable pages. + */ + COMPACT_PARTIAL_SKIPPED, + /* + * The full zone was compacted scanned but wasn't successfull to compact + * suitable pages. + */ COMPACT_COMPLETE, /* For more detailed tracepoint output */ COMPACT_NO_SUITABLE_PAGE, -- cgit v1.2.3-59-g8ed1b