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| author | Michal Hocko <mhocko@suse.com> | 2016-05-20 16:56:44 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-05-20 17:58:30 -0700 |
| commit | 1d4746d395975e0ff5103e20ab169d1a95b4ef9e (patch) | |
| tree | a5890a92a5059dde4f5746c544f3defcb2a80c88 /include/linux | |
| parent | c46649deae3f00aa8ba8716f0ddb8eef2dc9532f (diff) | |
| download | linux-stable-1d4746d395975e0ff5103e20ab169d1a95b4ef9e.tar.gz linux-stable-1d4746d395975e0ff5103e20ab169d1a95b4ef9e.tar.bz2 linux-stable-1d4746d395975e0ff5103e20ab169d1a95b4ef9e.zip | |
mm, compaction: distinguish COMPACT_DEFERRED from COMPACT_SKIPPED
try_to_compact_pages() can currently return COMPACT_SKIPPED even when
the compaction is defered for some zone just because zone DMA is skipped
in 99% of cases due to watermark checks. This makes COMPACT_DEFERRED
basically unusable for the page allocator as a feedback mechanism.
Make sure we distinguish those two states properly and switch their
ordering in the enum. This would mean that the COMPACT_SKIPPED will be
returned only when all eligible zones are skipped.
As a result COMPACT_DEFERRED handling for THP in __alloc_pages_slowpath
will be more precise and we would bail out rather than reclaim.
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/compaction.h | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/include/linux/compaction.h b/include/linux/compaction.h index 706cbf00e919..11f228712ed5 100644 --- a/include/linux/compaction.h +++ b/include/linux/compaction.h @@ -4,13 +4,16 @@ /* Return values for compact_zone() and try_to_compact_pages() */ /* When adding new states, please adjust include/trace/events/compaction.h */ enum compact_result { - /* compaction didn't start as it was deferred due to past failures */ - COMPACT_DEFERRED, /* * compaction didn't start as it was not possible or direct reclaim * was more suitable */ 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, + /* compaction should continue to another pageblock */ COMPACT_CONTINUE, /* |