[PATCH] mm: skip the page buddy block instead of one page

[Xishi Qiu]

A large free page buddy block will continue many times, so if the page 
is free, skip the whole page buddy block instead of one page.

Signed-off-by: Xishi Qiu <qiuxishi@xxxxxxxxxx>
---
 mm/compaction.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/mm/compaction.c b/mm/compaction.c
index 05ccb4c..874bae1 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -520,9 +520,10 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc,
 			goto next_pageblock;
 
 		/* Skip if free */
-		if (PageBuddy(page))
+		if (PageBuddy(page)) {
+			low_pfn += (1 << page_order(page)) - 1;
 			continue;
-
+		}
 		/*
 		 * For async migration, also only scan in MOVABLE blocks. Async
 		 * migration is optimistic to see if the minimum amount of work
-- 
1.7.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/