[PATCH 2/4] mm/memory_hotplug: avoid calling zone_intersects() for ZONE_NORMAL

From: Miaohe Lin
Date: Mon Feb 07 2022 - 08:54:59 EST


If zid reaches ZONE_NORMAL, the caller will always get the NORMAL zone no
matter what zone_intersects() returns. So we can save some possible cpu
cycles by avoid calling zone_intersects() for ZONE_NORMAL.

Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
---
mm/memory_hotplug.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index cbc67c27e0dd..140809e60e9a 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -826,7 +826,7 @@ static struct zone *default_kernel_zone_for_pfn(int nid, unsigned long start_pfn
struct pglist_data *pgdat = NODE_DATA(nid);
int zid;

- for (zid = 0; zid <= ZONE_NORMAL; zid++) {
+ for (zid = 0; zid < ZONE_NORMAL; zid++) {
struct zone *zone = &pgdat->node_zones[zid];

if (zone_intersects(zone, start_pfn, nr_pages))
--
2.23.0