memory notify consumers are only interested in which node the memory we
are adding belongs to, so replace current status_change_nid{_normal} fields
with only one that specifies the node.

Signed-off-by: Oscar Salvador <osalvador@suse.de>
---
 include/linux/memory.h |  3 +--
 mm/memory_hotplug.c    |  6 ++----
 mm/page_ext.c          | 12 +-----------
 3 files changed, 4 insertions(+), 17 deletions(-)

diff --git a/include/linux/memory.h b/include/linux/memory.h
index 1d814dfbb8a8..4d8884578a1a 100644
--- a/include/linux/memory.h
+++ b/include/linux/memory.h
@@ -117,8 +117,7 @@ struct memory_notify {
 	unsigned long altmap_nr_pages;
 	unsigned long start_pfn;
 	unsigned long nr_pages;
-	int status_change_nid_normal;
-	int status_change_nid;
+	int nid;
 };
 
 struct node_notify {
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 4bb9ff282ec9..185d799c79e2 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1198,6 +1198,7 @@ int online_pages(unsigned long pfn, unsigned long nr_pages,
 
 	mem_arg.start_pfn = pfn;
 	mem_arg.nr_pages = nr_pages;
+	mem_arg.nid = nid;
 	node_states_check_changes_online(nr_pages, zone, &node_arg);
 
 	if (node_arg.status_change_nid >= 0) {
@@ -1210,8 +1211,6 @@ int online_pages(unsigned long pfn, unsigned long nr_pages,
 	}
 
 	cancel_mem_notifier_on_err = true;
-	mem_arg.status_change_nid = node_arg.status_change_nid;
-	mem_arg.status_change_nid_normal = node_arg.status_change_nid_normal;
 	ret = memory_notify(MEM_GOING_ONLINE, &mem_arg);
 	ret = notifier_to_errno(ret);
 	if (ret)
@@ -2050,6 +2049,7 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages,
 
 	mem_arg.start_pfn = start_pfn;
 	mem_arg.nr_pages = nr_pages;
+	mem_arg.nid = node;
 	node_states_check_changes_offline(nr_pages, zone, &node_arg);
 
 	if (node_arg.status_change_nid >= 0) {
@@ -2061,8 +2061,6 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages,
 	}
 
 	cancel_mem_notifier_on_err = true;
-	mem_arg.status_change_nid = node_arg.status_change_nid;
-	mem_arg.status_change_nid_normal = node_arg.status_change_nid_normal;
 	ret = memory_notify(MEM_GOING_OFFLINE, &mem_arg);
 	ret = notifier_to_errno(ret);
 	if (ret) {
diff --git a/mm/page_ext.c b/mm/page_ext.c
index c351fdfe9e9a..477e6f24b7ab 100644
--- a/mm/page_ext.c
+++ b/mm/page_ext.c
@@ -378,16 +378,6 @@ static int __meminit online_page_ext(unsigned long start_pfn,
 	start = SECTION_ALIGN_DOWN(start_pfn);
 	end = SECTION_ALIGN_UP(start_pfn + nr_pages);
 
-	if (nid == NUMA_NO_NODE) {
-		/*
-		 * In this case, "nid" already exists and contains valid memory.
-		 * "start_pfn" passed to us is a pfn which is an arg for
-		 * online__pages(), and start_pfn should exist.
-		 */
-		nid = pfn_to_nid(start_pfn);
-		VM_BUG_ON(!node_online(nid));
-	}
-
 	for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION)
 		fail = init_section_page_ext(pfn, nid);
 	if (!fail)
@@ -436,7 +426,7 @@ static int __meminit page_ext_callback(struct notifier_block *self,
 	switch (action) {
 	case MEM_GOING_ONLINE:
 		ret = online_page_ext(mn->start_pfn,
-				   mn->nr_pages, mn->status_change_nid);
+				   mn->nr_pages, mn->nid);
 		break;
 	case MEM_OFFLINE:
 		offline_page_ext(mn->start_pfn,
-- 
2.49.0

On 4/1/25 11:27, Oscar Salvador wrote:
> memory notify consumers are only interested in which node the memory we
> are adding belongs to, so replace current status_change_nid{_normal} fields
> with only one that specifies the node.
> 
> Signed-off-by: Oscar Salvador <osalvador@suse.de>

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

On Tue, Apr 01, 2025 at 11:27:16AM +0200, Oscar Salvador wrote:
> memory notify consumers are only interested in which node the memory we
> are adding belongs to, so replace current status_change_nid{_normal} fields
> with only one that specifies the node.
> 
> Signed-off-by: Oscar Salvador <osalvador@suse.de>
> ---

Looks good to me,
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>

>  include/linux/memory.h |  3 +--
>  mm/memory_hotplug.c    |  6 ++----
>  mm/page_ext.c          | 12 +-----------
>  3 files changed, 4 insertions(+), 17 deletions(-)
> 
> diff --git a/mm/page_ext.c b/mm/page_ext.c
> index c351fdfe9e9a..477e6f24b7ab 100644
> --- a/mm/page_ext.c
> +++ b/mm/page_ext.c
> @@ -378,16 +378,6 @@ static int __meminit online_page_ext(unsigned long start_pfn,
>  	start = SECTION_ALIGN_DOWN(start_pfn);
>  	end = SECTION_ALIGN_UP(start_pfn + nr_pages);
>  
> -	if (nid == NUMA_NO_NODE) {
> -		/*
> -		 * In this case, "nid" already exists and contains valid memory.
> -		 * "start_pfn" passed to us is a pfn which is an arg for
> -		 * online__pages(), and start_pfn should exist.
> -		 */
> -		nid = pfn_to_nid(start_pfn);
> -		VM_BUG_ON(!node_online(nid));
> -	}

Ok, now that users who care 'status change' are using node notifier,
mem_arg.nid is the NUMA node the pfn range belongs to,
and always not NUMA_NO_NODE.

>  	for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION)
>  		fail = init_section_page_ext(pfn, nid);
>  	if (!fail)

-- 
Cheers,
Harry (formerly known as Hyeonggon)