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-rw-r--r--mm/page_alloc.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index b5a58d476c1a..d73bfad1c32f 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -847,8 +847,19 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order,
struct page *page = __rmqueue(zone, order, migratetype);
if (unlikely(page == NULL))
break;
+
+ /*
+ * Split buddy pages returned by expand() are received here
+ * in physical page order. The page is added to the callers and
+ * list and the list head then moves forward. From the callers
+ * perspective, the linked list is ordered by page number in
+ * some conditions. This is useful for IO devices that can
+ * merge IO requests if the physical pages are ordered
+ * properly.
+ */
list_add(&page->lru, list);
set_page_private(page, migratetype);
+ list = &page->lru;
}
spin_unlock(&zone->lock);
return i;