memory-tier is only concerned when a numa node changes its memory state,
because it then needs to re-create the demotion list.
So stop using the memory notifier and use the new numa node notifer
instead.

Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Hildenbrand <david@redhat.com>
---
 mm/memory-tiers.c | 19 ++++++-------------
 1 file changed, 6 insertions(+), 13 deletions(-)

diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c
index fc14fe53e9b7..0382b6942b8b 100644
--- a/mm/memory-tiers.c
+++ b/mm/memory-tiers.c
@@ -872,25 +872,18 @@ static int __meminit memtier_hotplug_callback(struct notifier_block *self,
 					      unsigned long action, void *_arg)
 {
 	struct memory_tier *memtier;
-	struct memory_notify *arg = _arg;
-
-	/*
-	 * Only update the node migration order when a node is
-	 * changing status, like online->offline.
-	 */
-	if (arg->status_change_nid < 0)
-		return notifier_from_errno(0);
+	struct node_notify *nn = _arg;
 
 	switch (action) {
-	case MEM_OFFLINE:
+	case NODE_REMOVED_LAST_MEMORY:
 		mutex_lock(&memory_tier_lock);
-		if (clear_node_memory_tier(arg->status_change_nid))
+		if (clear_node_memory_tier(nn->nid))
 			establish_demotion_targets();
 		mutex_unlock(&memory_tier_lock);
 		break;
-	case MEM_ONLINE:
+	case NODE_ADDED_FIRST_MEMORY:
 		mutex_lock(&memory_tier_lock);
-		memtier = set_node_memory_tier(arg->status_change_nid);
+		memtier = set_node_memory_tier(nn->nid);
 		if (!IS_ERR(memtier))
 			establish_demotion_targets();
 		mutex_unlock(&memory_tier_lock);
@@ -929,7 +922,7 @@ static int __init memory_tier_init(void)
 	nodes_and(default_dram_nodes, node_states[N_MEMORY],
 		  node_states[N_CPU]);
 
-	hotplug_memory_notifier(memtier_hotplug_callback, MEMTIER_HOTPLUG_PRI);
+	hotplug_node_notifier(memtier_hotplug_callback, MEMTIER_HOTPLUG_PRI);
 	return 0;
 }
 subsys_initcall(memory_tier_init);
-- 
2.49.0