[PATCH] mm/page_alloc: simplify update of pgdat in wake_all_kswapds

[Chen Wandun]

There is no need to update last_pgdat for each zone,
only update last_pgdat when iterating the first zone
of a node.

Signed-off-by: Chen Wandun <chenwandun@xxxxxxxxxx>
---
 mm/page_alloc.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index f648decfe39d..ea282630aedc 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4674,9 +4674,10 @@ static void wake_all_kswapds(unsigned int order, gfp_t gfp_mask,
 
 	for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, highest_zoneidx,
 					ac->nodemask) {
-		if (last_pgdat != zone->zone_pgdat)
+		if (last_pgdat != zone->zone_pgdat) {
 			wakeup_kswapd(zone, gfp_mask, order, highest_zoneidx);
-		last_pgdat = zone->zone_pgdat;
+			last_pgdat = zone->zone_pgdat;
+		}
 	}
 }
 
-- 
2.18.0.huawei.25