diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 6383557..0353002 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3378,7 +3378,8 @@
 		 * is used by this zone for memmap. This affects the watermark
 		 * and per-cpu initialisations
 		 */
-		memmap_pages = (size * sizeof(struct page)) >> PAGE_SHIFT;
+		memmap_pages =
+			PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT;
 		if (realsize >= memmap_pages) {
 			realsize -= memmap_pages;
 			printk(KERN_DEBUG