]> git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/commit
mm, compaction: distinguish COMPACT_DEFERRED from COMPACT_SKIPPED
authorMichal Hocko <mhocko@suse.com>
Fri, 20 May 2016 23:56:44 +0000 (16:56 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sat, 21 May 2016 00:58:30 +0000 (17:58 -0700)
commit1d4746d395975e0ff5103e20ab169d1a95b4ef9e
treea5890a92a5059dde4f5746c544f3defcb2a80c88
parentc46649deae3f00aa8ba8716f0ddb8eef2dc9532f
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>
include/linux/compaction.h
include/trace/events/compaction.h
mm/compaction.c