From: Johannes Weiner <hannes@saeurebad.de>
Date: Fri, 23 May 2008 20:04:21 +0000 (-0700)
Subject: mm: don't drop a partial page in a zone's memory map size
X-Git-Tag: Ubuntu-5.13.0-19.19~42045
X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=f7232154198f928fc25f420d6190468212a7632a;p=mirror_ubuntu-jammy-kernel.git

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 63835579323a..035300299f94 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3378,7 +3378,8 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat,
 		 * 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