Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 3.14 23/37] mm/compaction: do not call suitable_migration_target() on every page | Date | Tue, 7 Oct 2014 16:19:40 -0700 |
| |
3.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
commit 01ead5340bcf5f3a1cd2452c75516d0ef4d908d7 upstream.
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> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- mm/compaction.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)
--- a/mm/compaction.c +++ b/mm/compaction.c @@ -244,6 +244,7 @@ static unsigned long isolate_freepages_b 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_b 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))
| |