Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 01ead534 authored by Joonsoo Kim's avatar Joonsoo Kim Committed by Linus Torvalds
Browse files

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: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7d348b9e

mm/compaction.c

+11 −2
Original line number Diff line number Diff line
@@ -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))

		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))