From: Miaohe Lin <linmiaohe@xxxxxxxxxx> Subject: mm/memory_hotplug: avoid calling zone_intersects() for ZONE_NORMAL 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. Link: https://lkml.kernel.org/r/20220207133643.23427-3-linmiaohe@xxxxxxxxxx Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> Reviewed-by: Oscar Salvador <osalvador@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memory_hotplug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/memory_hotplug.c~mm-memory_hotplug-avoid-calling-zone_intersects-for-zone_normal +++ a/mm/memory_hotplug.c @@ -823,7 +823,7 @@ static struct zone *default_kernel_zone_ 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)) _
