mm/page_alloc: simplify update of pgdat in wake_all_kswapds

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

Link: https://lkml.kernel.org/r/20220322115635.2708989-1-chenwandun@huawei.com
Signed-off-by: Chen Wandun <chenwandun@huawei.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 6b55fe38d646baaec398886cf01a9e3c956940e4..1b92795ae5e28bd6d1839ce18d7753fa6b9044e7 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4678,9 +4678,10 @@ 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;
+               }
        }
 }