mm,memory-tiers: use node-notifier instead of memory-notifier

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.

Link: https://lkml.kernel.org/r/20250616135158.450136-6-osalvador@suse.de
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>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Rakie Kim <rakie.kim@sk.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c
index fc14fe53e9b7509d190c98b62de82ee6ced0909b..0382b6942b8bd4d6650e340d9f88e31365e851dd 100644 (file)
--- 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);