From: Wei Yang Subject: mm/vmscan: make sure wakeup_kswapd with managed zone 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(). And it also use managed_zone in migrate_balanced_pgdat() to get the proper zone. Link: https://lkml.kernel.org/r/20220327024101.10378-2-richard.weiyang@gmail.com Signed-off-by: Wei Yang Reviewed-by: "Huang, Ying" Reviewed-by: Miaohe Lin Reviewed-by: David Hildenbrand Cc: Mel Gorman Cc: Oscar Salvador Signed-off-by: Andrew Morton --- mm/migrate.c | 2 +- mm/page_alloc.c | 2 ++ 2 files changed, 3 insertions(+), 1 deletion(-) --- a/mm/migrate.c~mm-vmscan-make-sure-wakeup_kswapd-with-managed-zone +++ a/mm/migrate.c @@ -2044,7 +2044,7 @@ static int numamigrate_isolate_page(pg_d 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); --- a/mm/page_alloc.c~mm-vmscan-make-sure-wakeup_kswapd-with-managed-zone +++ a/mm/page_alloc.c @@ -4630,6 +4630,8 @@ static void wake_all_kswapds(unsigned in 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; _