[PATCH v5 10/10] mm,memory_hotplug: Rename status_change_nid parameter in memory_notify

[Oscar Salvador <osalvador@suse.de>]

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'.

Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Oscar Salvador <osalvador@suse.de>
---
 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(-)

diff --git a/Documentation/core-api/memory-hotplug.rst b/Documentation/core-api/memory-hotplug.rst
index b19c3be7437d..97efb7b651ac 100644
--- a/Documentation/core-api/memory-hotplug.rst
+++ b/Documentation/core-api/memory-hotplug.rst
@@ -59,17 +59,12 @@ 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;
+		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
diff --git a/include/linux/memory.h b/include/linux/memory.h
index a9ccd6579422..918c65ecf299 100644
--- a/include/linux/memory.h
+++ b/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;
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 0550f3061fc4..bccbc02ed122 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1186,7 +1186,7 @@ int online_pages(unsigned long pfn, unsigned long nr_pages,
 
 	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);
@@ -1987,7 +1987,7 @@ 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.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);
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