Re: [PATCH v7 11/11] mm,memory_hotplug: Drop status_change_nid parameter from memory_notify

[Vlastimil Babka <vbabka@suse.cz>]

On 6/16/25 3:51 PM, Oscar Salvador wrote:
> There no users left of status_change_nid, so drop it from memory_notify
> struct.
> 
> Suggested-by: David Hildenbrand <david@redhat.com>
> Signed-off-by: Oscar Salvador <osalvador@suse.de>
> Acked-by: David Hildenbrand <david@redhat.com>

Reviewed-by: Vlastimil Babka <vbabka@suse.cz>

> ---
>  Documentation/core-api/memory-hotplug.rst | 7 -------
>  include/linux/memory.h                    | 1 -
>  mm/memory_hotplug.c                       | 4 ----
>  3 files changed, 12 deletions(-)
> 
> diff --git a/Documentation/core-api/memory-hotplug.rst b/Documentation/core-api/memory-hotplug.rst
> index fb84e78968b2..8fc97c2379de 100644
> --- a/Documentation/core-api/memory-hotplug.rst
> +++ b/Documentation/core-api/memory-hotplug.rst
> @@ -59,17 +59,10 @@ The third argument (arg) passes a pointer of struct memory_notify::
>  	struct memory_notify {
>  		unsigned long start_pfn;
>  		unsigned long nr_pages;
> -		int status_change_nid;
>  	}
>  
>  - start_pfn is start_pfn of online/offline memory.
>  - nr_pages is # of pages of online/offline memory.
> -- status_change_nid is set node id when N_MEMORY of nodemask is (will be)
> -  set/clear. It means a new(memoryless) node gets new memory by online and a
> -  node loses all memory. If this is -1, then nodemask status is not changed.
> -
> -  If status_changed_nid* >= 0, callback should create/discard structures for the
> -  node if necessary.
>  
>  It is possible to get notified for MEM_CANCEL_ONLINE without having been notified
>  for MEM_GOING_ONLINE, and the same applies to MEM_CANCEL_OFFLINE and
> diff --git a/include/linux/memory.h b/include/linux/memory.h
> index a9ccd6579422..de8b898ada3f 100644
> --- a/include/linux/memory.h
> +++ b/include/linux/memory.h
> @@ -109,7 +109,6 @@ struct memory_notify {
>  	unsigned long altmap_nr_pages;
>  	unsigned long start_pfn;
>  	unsigned long nr_pages;
> -	int status_change_nid;
>  };
>  
>  struct notifier_block;
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index e8ccfe4cada2..bfaa570c0685 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -1153,7 +1153,6 @@ int online_pages(unsigned long pfn, unsigned long nr_pages,
>  	struct memory_notify mem_arg = {
>  		.start_pfn = pfn,
>  		.nr_pages = nr_pages,
> -		.status_change_nid = NUMA_NO_NODE,
>  	};
>  	struct node_notify node_arg = {
>  		.nid = NUMA_NO_NODE,
> @@ -1181,7 +1180,6 @@ int online_pages(unsigned long pfn, unsigned long nr_pages,
>  	if (!node_state(nid, N_MEMORY)) {
>  		/* Adding memory to the node for the first time */
>  		node_arg.nid = nid;
> -		mem_arg.status_change_nid = nid;
>  		ret = node_notify(NODE_ADDING_FIRST_MEMORY, &node_arg);
>  		ret = notifier_to_errno(ret);
>  		if (ret)
> @@ -1905,7 +1903,6 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages,
>  	struct memory_notify mem_arg = {
>  		.start_pfn = start_pfn,
>  		.nr_pages = nr_pages,
> -		.status_change_nid = NUMA_NO_NODE,
>  	};
>  	struct node_notify node_arg = {
>  		.nid = NUMA_NO_NODE,
> @@ -1976,7 +1973,6 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages,
>  	 */
>  	if (nr_pages >= pgdat->node_present_pages) {
>  		node_arg.nid = node;
> -		mem_arg.status_change_nid = node;
>  		ret = node_notify(NODE_REMOVING_LAST_MEMORY, &node_arg);
>  		ret = notifier_to_errno(ret);
>  		if (ret)