From 4f9a358c36fcdad3ea1db263ec4d484a70ad543e Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Fri, 20 May 2016 16:56:50 -0700 Subject: [PATCH] mm, compaction: update compaction_result ordering compaction_result will be used as the primary feedback channel for compaction users. At the same time try_to_compact_pages (and potentially others) assume a certain ordering where a more specific feedback takes precendence. This gets a bit awkward when we have conflicting feedback from different zones. E.g one returing COMPACT_COMPLETE meaning the full zone has been scanned without any outcome while other returns with COMPACT_PARTIAL aka made some progress. The caller should get COMPACT_PARTIAL because that means that the compaction still can make some progress. The same applies for COMPACT_PARTIAL vs COMPACT_PARTIAL_SKIPPED. Reorder PARTIAL to be the largest one so the larger the value is the more progress we have done. 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 | 26 ++++++++++++++++---------- 1 file changed, 16 insertions(+), 10 deletions(-) diff --git a/include/linux/compaction.h b/include/linux/compaction.h index 9b37f9d3f7a8..ff39fa0a1ede 100644 --- a/include/linux/compaction.h +++ b/include/linux/compaction.h @@ -4,6 +4,8 @@ /* Return values for compact_zone() and try_to_compact_pages() */ /* When adding new states, please adjust include/trace/events/compaction.h */ enum compact_result { + /* For more detailed tracepoint output - internal to compaction */ + COMPACT_NOT_SUITABLE_ZONE, /* * compaction didn't start as it was not possible or direct reclaim * was more suitable @@ -11,30 +13,34 @@ enum compact_result { COMPACT_SKIPPED, /* compaction didn't start as it was deferred due to past failures */ COMPACT_DEFERRED, + /* compaction not active last round */ COMPACT_INACTIVE = COMPACT_DEFERRED, + /* For more detailed tracepoint output - internal to compaction */ + COMPACT_NO_SUITABLE_PAGE, /* compaction should continue to another pageblock */ COMPACT_CONTINUE, + /* - * direct compaction partially compacted a zone and there are suitable - * pages + * The full zone was compacted scanned but wasn't successfull to compact + * suitable pages. */ - COMPACT_PARTIAL, + COMPACT_COMPLETE, /* * direct compaction has scanned part of the zone but wasn't successfull * to compact suitable pages. */ COMPACT_PARTIAL_SKIPPED, + + /* compaction terminated prematurely due to lock contentions */ + COMPACT_CONTENDED, + /* - * The full zone was compacted scanned but wasn't successfull to compact - * suitable pages. + * direct compaction partially compacted a zone and there might be + * suitable pages */ - COMPACT_COMPLETE, - /* For more detailed tracepoint output */ - COMPACT_NO_SUITABLE_PAGE, - COMPACT_NOT_SUITABLE_ZONE, - COMPACT_CONTENDED, + COMPACT_PARTIAL, }; /* Used to signal whether compaction detected need_sched() or lock contention */ -- GitLab