[PATCH v6 09/10] mm,mempolicy: Use node-notifier instead of memory-notifier

Oscar Salvador
2025-06-09T09:22:42Z

mempolicy is only concerned when a numa node changes its memory state,
because it needs to take this node into account for the auto-weighted
memory policy system.
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>
Reviewed-by: Rakie Kim <rakie.kim@sk.com>
---
mm/mempolicy.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 72fd72e156b1..693319c2652d 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -3793,20 +3793,17 @@ static int wi_node_notifier(struct notifier_block *nb,
unsigned long action, void *data)
{
int err;
- struct memory_notify *arg = data;
- int nid = arg->status_change_nid;
-
- if (nid < 0)
- return NOTIFY_OK;
+ struct node_notify *nn = data;
+ int nid = nn->nid;

switch (action) {
- case MEM_ONLINE:
+ case NODE_ADDED_FIRST_MEMORY:
err = sysfs_wi_node_add(nid);
if (err)
pr_err("failed to add sysfs for node%d during hotplug: %d\n",
nid, err);
break;
- case MEM_OFFLINE:
+ case NODE_REMOVED_LAST_MEMORY:
sysfs_wi_node_delete(nid);
break;
}
@@ -3845,7 +3842,7 @@ static int __init add_weighted_interleave_group(struct kobject *mempolicy_kobj)
}
}

- hotplug_memory_notifier(wi_node_notifier, DEFAULT_CALLBACK_PRI);
+ hotplug_node_notifier(wi_node_notifier, DEFAULT_CALLBACK_PRI);
return 0;

err_cleanup_kobj:
--
2.49.0