diff mbox series

[5.12,350/700] mm/page_alloc: fix counting of managed_pages

Message ID 20210712061013.542249386@linuxfoundation.org
State Superseded
Headers show
Series None | expand

Commit Message

Greg KH July 12, 2021, 6:07 a.m. UTC 
From: Liu Shixin <liushixin2@huawei.com>

[ Upstream commit f7ec104458e00d27a190348ac3a513f3df3699a4 ]

commit f63661566fad ("mm/page_alloc.c: clear out zone->lowmem_reserve[] if
the zone is empty") clears out zone->lowmem_reserve[] if zone is empty.
But when zone is not empty and sysctl_lowmem_reserve_ratio[i] is set to
zero, zone_managed_pages(zone) is not counted in the managed_pages either.
This is inconsistent with the description of lowmem_reserve, so fix it.

Link: https://lkml.kernel.org/r/20210527125707.3760259-1-liushixin2@huawei.com
Fixes: f63661566fad ("mm/page_alloc.c: clear out zone->lowmem_reserve[] if the zone is empty")
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Reported-by: yangerkun <yangerkun@huawei.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 mm/page_alloc.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)
diff mbox series

Patch

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 25c83640d47a..382af5377274 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -7894,14 +7894,14 @@  static void setup_per_zone_lowmem_reserve(void)
 			unsigned long managed_pages = 0;
 
 			for (j = i + 1; j < MAX_NR_ZONES; j++) {
-				if (clear) {
-					zone->lowmem_reserve[j] = 0;
-				} else {
-					struct zone *upper_zone = &pgdat->node_zones[j];
+				struct zone *upper_zone = &pgdat->node_zones[j];
+
+				managed_pages += zone_managed_pages(upper_zone);
 
-					managed_pages += zone_managed_pages(upper_zone);
+				if (clear)
+					zone->lowmem_reserve[j] = 0;
+				else
 					zone->lowmem_reserve[j] = managed_pages / ratio;
-				}
 			}
 		}
 	}