Re: [PATCH v5 05/10] mm,memory-tiers: Use node-notifier instead of memory-notifier

[David Hildenbrand <david@redhat.com>]

On 05.06.25 16:22, Oscar Salvador wrote:
> 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 | 14 +++++++-------
>   1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c
> index fc14fe53e9b7..67f06e6264a1 100644
> --- a/mm/memory-tiers.c
> +++ b/mm/memory-tiers.c
> @@ -872,25 +872,25 @@ static int __meminit memtier_hotplug_callback(struct notifier_block *self,
>   					      unsigned long action, void *_arg)
>   {
>   	struct memory_tier *memtier;
> -	struct memory_notify *arg = _arg;
> +	struct node_notify *narg = _arg;
>   
>   	/*
>   	 * Only update the node migration order when a node is
>   	 * changing status, like online->offline.
>   	 */
> -	if (arg->status_change_nid < 0)
> +	if (narg->nid < 0)
>   		return notifier_from_errno(0);

Ehm, why are we ever calling a node notifier with nid < 0 ?

We shouldn't do that.

Can be adding first / removing last from something that ... is not a 
valid node? :)

Maybe it's already do that way, in that case just drop this check here.

-- 
Cheers,

David / dhildenb