[PATCH 08/10] mm/page_alloc: use get_onbuddy_migratetype() to get buddy list type

[Joonsoo Kim]

When isolating free page, what we want to know is which list
the page is linked. If it is linked in isolate migratetype buddy list,
we can skip watermark check and freepage counting. And if it is linked
in CMA migratetype buddy list, we need to fixup freepage counting. For
this purpose, get_onbuddy_migratetype() is more fit and cheap than
get_pageblock_migratetype(). So use it.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
---
 mm/page_alloc.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e1c4c3e..d9fb8bb 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1597,7 +1597,7 @@ static int __isolate_free_page(struct page *page, unsigned int order)
 	BUG_ON(!PageBuddy(page));
 
 	zone = page_zone(page);
-	mt = get_pageblock_migratetype(page);
+	mt = get_onbuddy_migratetype(page);
 
 	if (!is_migrate_isolate(mt)) {
 		/* Obey watermarks as if the page was being allocated */
-- 
1.7.9.5

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