[PATCH v6 05/10] mm,memory-tiers: Use node-notifier instead of memory-notifier

Oscar Salvador
2025-06-09T09:22:30Z

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>
---
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