[PATCH 2/2] mm/vmscan: make sure wakeup_kswapd with managed zone

Wei Yang
2022-03-27T02:41:33Z

wakeup_kswapd() only wake up kswapd when the zone is managed.

For two callers of wakeup_kswapd(), they are node perspective.

* wake_all_kswapds
* numamigrate_isolate_page

If we picked up a !managed zone, this is not we expected.

This patch makes sure we pick up a managed zone for wakeup_kswapd().

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
---
mm/migrate.c | 2 +-
mm/page_alloc.c | 2 ++
2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index 3d60823afd2d..c4b654c0bdf0 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2046,7 +2046,7 @@ static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page)
if (!(sysctl_numa_balancing_mode & NUMA_BALANCING_MEMORY_TIERING))
return 0;
for (z = pgdat->nr_zones - 1; z >= 0; z--) {
- if (populated_zone(pgdat->node_zones + z))
+ if (managed_zone(pgdat->node_zones + z))
break;
}
wakeup_kswapd(pgdat->node_zones + z, 0, order, ZONE_MOVABLE);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 4c0c4ef94ba0..6656c2d06e01 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4674,6 +4674,8 @@ 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 (!managed_zone(zone))
+ continue;
if (last_pgdat != zone->zone_pgdat)
wakeup_kswapd(zone, gfp_mask, order, highest_zoneidx);
last_pgdat = zone->zone_pgdat;
--
2.33.1