tree 6a2ce9b629b3432328a9f2f6539ea4c57ccc83da
parent 70ef57e6c22c3323dce179b7d0d433c479266612
author Joonsoo Kim <iamjoonsoo.kim@lge.com> 1396910223 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1396913751 -0700

mm/compaction: disallow high-order page for migration target

Purpose of compaction is to get a high order page.  Currently, if we
find high-order page while searching migration target page, we break it
to order-0 pages and use them as migration target.  It is contrary to
purpose of compaction, so disallow high-order page to be used for
migration target.

Additionally, clean-up logic in suitable_migration_target() to simplify
the code.  There is no functional changes from this clean-up.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>