mm: don't drop a partial page in a zone's memory map size
In a zone's present pages number, account for all pages occupied by the
memory map, including a partial.
Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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