[PATCH v7 09/11] mm,mempolicy: Use node-notifier instead of memory-notifier

Oscar Salvador posted 11 patches 3 months, 3 weeks ago
[PATCH v7 09/11] mm,mempolicy: Use node-notifier instead of memory-notifier
Posted by Oscar Salvador 3 months, 3 weeks ago
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>
Acked-by: David Hildenbrand <david@redhat.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
Re: [PATCH v7 09/11] mm,mempolicy: Use node-notifier instead of memory-notifier
Posted by Gregory Price 3 months, 3 weeks ago
On Mon, Jun 16, 2025 at 03:51:52PM +0200, Oscar Salvador wrote:
> 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>
> Acked-by: David Hildenbrand <david@redhat.com>

Sorry for the late chime-in, thank you for doing this clean up, this all
looks awesome.

Reviewed-by: Gregory Price <gourry@gourry.net>