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| author |   Joonsoo Kim <iamjoonsoo.kim@lge.com> | 2014-04-07 15:37:04 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2014-04-07 16:35:51 -0700 |
| commit | 01ead5340bcf5f3a1cd2452c75516d0ef4d908d7 (patch) | |
| tree | eabccdd2c4f1b399ab04e0cc4ed8acff9f2d0281 /mm/compaction.c | |
| parent | mm/compaction: disallow high-order page for migration target (diff) | |
| download | linux-dev-01ead5340bcf5f3a1cd2452c75516d0ef4d908d7.tar.xz linux-dev-01ead5340bcf5f3a1cd2452c75516d0ef4d908d7.zip | |
mm/compaction: do not call suitable_migration_target() on every page
suitable_migration_target() checks that pageblock is suitable for
migration target. In isolate_freepages_block(), it is called on every
page and this is inefficient. So make it called once per pageblock.
suitable_migration_target() also checks if page is highorder or not, but
it's criteria for highorder is pageblock order. So calling it once
within pageblock range has no problem.
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>
Diffstat (limited to 'mm/compaction.c')
| -rw-r--r-- | mm/compaction.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/mm/compaction.c b/mm/compaction.c index 9a03fdb1fd84..3a1828541dc0 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -244,6 +244,7 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, struct page *cursor, *valid_page = NULL; unsigned long flags; bool locked = false; + bool checked_pageblock = false; cursor = pfn_to_page(blockpfn); @@ -275,8 +276,16 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, break; /* Recheck this is a suitable migration target under lock */ - if (!strict && !suitable_migration_target(page)) - break; + if (!strict && !checked_pageblock) { + /* + * We need to check suitability of pageblock only once + * and this isolate_freepages_block() is called with + * pageblock range, so just check once is sufficient. + */ + checked_pageblock = true; + if (!suitable_migration_target(page)) + break; + } /* Recheck this is a buddy page under lock */ if (!PageBuddy(page)) |