Re: [PATCH v5 09/10] mm,mempolicy: Use node-notifier instead of memory-notifier

[Rakie Kim]

On Thu,  5 Jun 2025 16:23:00 +0200 Oscar Salvador <osalvador@xxxxxxx> 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@xxxxxxx>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> Reviewed-by: Harry Yoo <harry.yoo@xxxxxxxxxx>
> Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx>
> ---
>  mm/mempolicy.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index 72fd72e156b1..1b87628f3cfc 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -3793,20 +3793,20 @@ 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;
> +	struct node_notify *arg = data;
> +	int nid = arg->nid;
>  
>  	if (nid < 0)
>  		return NOTIFY_OK;
>  
>  	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 +3845,7 @@ 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
> 

Reviewed-by: Rakie Kim <rakie.kim@xxxxxx>

Rakie