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| author | Joonsoo Kim <iamjoonsoo.kim@lge.com> | 2014-04-07 15:37:03 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-10-09 12:21:28 -0700 |
| commit | 96b3fde44d498edb0b69f38ee09f3fcc0060d214 (patch) | |
| tree | f8b5b9d4dd9bae65778b39fdbb1f7bdb9a483ac1 /mm | |
| parent | 1190e5c69c4329c8b8d220e8c149906af1e787c8 (diff) | |
| download | lwn-96b3fde44d498edb0b69f38ee09f3fcc0060d214.tar.gz lwn-96b3fde44d498edb0b69f38ee09f3fcc0060d214.zip | |
mm/compaction: disallow high-order page for migration target
commit 7d348b9ea64db0a315d777ce7d4b06697f946503 upstream.
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>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/compaction.c | 15 |
1 files changed, 3 insertions, 12 deletions
diff --git a/mm/compaction.c b/mm/compaction.c index d5636f939bf0..fcb05da931ff 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -217,21 +217,12 @@ static inline bool compact_trylock_irqsave(spinlock_t *lock, /* Returns true if the page is within a block suitable for migration to */ static bool suitable_migration_target(struct page *page) { - int migratetype = get_pageblock_migratetype(page); - - /* Don't interfere with memory hot-remove or the min_free_kbytes blocks */ - if (migratetype == MIGRATE_RESERVE) - return false; - - if (is_migrate_isolate(migratetype)) - return false; - - /* If the page is a large free page, then allow migration */ + /* If the page is a large free page, then disallow migration */ if (PageBuddy(page) && page_order(page) >= pageblock_order) - return true; + return false; /* If the block is MIGRATE_MOVABLE or MIGRATE_CMA, allow migration */ - if (migrate_async_suitable(migratetype)) + if (migrate_async_suitable(get_pageblock_migratetype(page))) return true; /* Otherwise skip the block */ |