mm/page_alloc: fix counting of managed_pages

commit f636615 ("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/[email protected] Fixes: f636615 ("mm/page_alloc.c: clear out zone->lowmem_reserve[] if the zone is empty") Signed-off-by: Liu Shixin <[email protected]> Reported-by: yangerkun <[email protected]> Reviewed-by: Baoquan He <[email protected]> Acked-by: David Hildenbrand <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
sm00th · Jun 29, 2021 · f7ec104 · f7ec104
1 parent e47aa90
commit f7ec104
Showing 1 changed file with 6 additions and 6 deletions.
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
@@ -8240,14 +8240,14 @@ 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;
-				}
 			}
 		}
 	}