+ mmmemory_hotplug-rename-status_change_nid-parameter-in-memory_notify.patch added to mm-new branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm,memory_hotplug: rename status_change_nid parameter in memory_notify
has been added to the -mm mm-new branch.  Its filename is
     mmmemory_hotplug-rename-status_change_nid-parameter-in-memory_notify.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mmmemory_hotplug-rename-status_change_nid-parameter-in-memory_notify.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
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------------------------------------------------------
From: Oscar Salvador <osalvador@suse.de>
Subject: mm,memory_hotplug: rename status_change_nid parameter in memory_notify
Date: Thu, 5 Jun 2025 16:23:01 +0200

The 'status_change_nid' field was used to track changes in the memory
state of a numa node, but that funcionality has been decoupled from
memory_notify and moved to node_notify.  Current consumers of
memory_notify are only interested in which node the memory we are adding
belongs to, so rename current 'status_change_nid' to 'nid'.

Link: https://lkml.kernel.org/r/20250605142305.244465-11-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com>
Cc: Rakie Kim <rakie.kim@sk.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 Documentation/core-api/memory-hotplug.rst |    9 ++-------
 include/linux/memory.h                    |    2 +-
 mm/memory_hotplug.c                       |    4 ++--
 mm/page_ext.c                             |   12 +-----------
 4 files changed, 6 insertions(+), 21 deletions(-)

--- a/Documentation/core-api/memory-hotplug.rst~mmmemory_hotplug-rename-status_change_nid-parameter-in-memory_notify
+++ a/Documentation/core-api/memory-hotplug.rst
@@ -59,17 +59,12 @@ The third argument (arg) passes a pointe
 	struct memory_notify {
 		unsigned long start_pfn;
 		unsigned long nr_pages;
-		int status_change_nid;
+		int 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.
+- nid is set to the node id, where the memory we are adding or removing belongs to.
 
 The callback routine shall return one of the values
 NOTIFY_DONE, NOTIFY_OK, NOTIFY_BAD, NOTIFY_STOP
--- a/include/linux/memory.h~mmmemory_hotplug-rename-status_change_nid-parameter-in-memory_notify
+++ a/include/linux/memory.h
@@ -109,7 +109,7 @@ struct memory_notify {
 	unsigned long altmap_nr_pages;
 	unsigned long start_pfn;
 	unsigned long nr_pages;
-	int status_change_nid;
+	int nid;
 };
 
 struct notifier_block;
--- a/mm/memory_hotplug.c~mmmemory_hotplug-rename-status_change_nid-parameter-in-memory_notify
+++ a/mm/memory_hotplug.c
@@ -1186,7 +1186,7 @@ int online_pages(unsigned long pfn, unsi
 
 	mem_arg.start_pfn = pfn;
 	mem_arg.nr_pages = nr_pages;
-	mem_arg.status_change_nid = node_arg.nid;
+	mem_arg.nid = node_arg.nid;
 	cancel_mem_notifier_on_err = true;
 	ret = memory_notify(MEM_GOING_ONLINE, &mem_arg);
 	ret = notifier_to_errno(ret);
@@ -1986,7 +1986,7 @@ int offline_pages(unsigned long start_pf
 
 	mem_arg.start_pfn = start_pfn;
 	mem_arg.nr_pages = nr_pages;
-	mem_arg.status_change_nid = node_arg.nid;
+	mem_arg.nid = node_arg.nid;
 	cancel_mem_notifier_on_err = true;
 	ret = memory_notify(MEM_GOING_OFFLINE, &mem_arg);
 	ret = notifier_to_errno(ret);
--- a/mm/page_ext.c~mmmemory_hotplug-rename-status_change_nid-parameter-in-memory_notify
+++ a/mm/page_ext.c
@@ -378,16 +378,6 @@ static int __meminit online_page_ext(uns
 	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(s
 	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,
_

Patches currently in -mm which might be from osalvador@suse.de are

mmslub-do-not-special-case-n_normal-nodes-for-slab_nodes.patch
mmmemory_hotplug-remove-status_change_nid_normal-and-update-documentation.patch
mmmemory_hotplug-implement-numa-node-notifier.patch
mmslub-use-node-notifier-instead-of-memory-notifier.patch
mmmemory-tiers-use-node-notifier-instead-of-memory-notifier.patch
driverscxl-use-node-notifier-instead-of-memory-notifier.patch
drivershmat-use-node-notifier-instead-of-memory-notifier.patch
kernelcpuset-use-node-notifier-instead-of-memory-notifier.patch
mmmempolicy-use-node-notifier-instead-of-memory-notifier.patch
mmmemory_hotplug-rename-status_change_nid-parameter-in-memory_notify.patch