[PATCH v1 1/2] mm/memory_hotplug: pass in nid to online_pages()

[David Hildenbrand]

No need to lookup the memory block, we can directly pass in the nid.

Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
 drivers/base/memory.c          |  6 +++---
 include/linux/memory_hotplug.h |  3 ++-
 mm/memory_hotplug.c            | 13 ++-----------
 3 files changed, 7 insertions(+), 15 deletions(-)

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 2604a15c728b..2cf3542b04d0 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -236,7 +236,7 @@ static bool pages_correctly_probed(unsigned long start_pfn)
  */
 static int
 memory_block_action(unsigned long start_section_nr, unsigned long action,
-		    int online_type)
+		    int online_type, int nid)
 {
 	unsigned long start_pfn;
 	unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block;
@@ -249,7 +249,7 @@ memory_block_action(unsigned long start_section_nr, unsigned long action,
 		if (!pages_correctly_probed(start_pfn))
 			return -EBUSY;
 
-		ret = online_pages(start_pfn, nr_pages, online_type);
+		ret = online_pages(start_pfn, nr_pages, online_type, nid);
 		break;
 	case MEM_OFFLINE:
 		ret = offline_pages(start_pfn, nr_pages);
@@ -275,7 +275,7 @@ static int memory_block_change_state(struct memory_block *mem,
 		mem->state = MEM_GOING_OFFLINE;
 
 	ret = memory_block_action(mem->start_section_nr, to_state,
-				mem->online_type);
+				  mem->online_type, mem->nid);
 
 	mem->state = ret ? from_state_req : to_state;
 
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 820689093894..f4d59155f3d4 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -94,7 +94,8 @@ extern int zone_grow_free_lists(struct zone *zone, unsigned long new_nr_pages);
 extern int zone_grow_waitqueues(struct zone *zone, unsigned long nr_pages);
 extern int add_one_highpage(struct page *page, int pfn, int bad_ppro);
 /* VM interface that may be used by firmware interface */
-extern int online_pages(unsigned long, unsigned long, int);
+extern int online_pages(unsigned long pfn, unsigned long nr_pages,
+			int online_type, int nid);
 extern struct zone *test_pages_in_a_zone(unsigned long start_pfn,
 					 unsigned long end_pfn);
 extern unsigned long __offline_isolated_pages(unsigned long start_pfn,
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 5ee2c6e10934..fb1c878d054d 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -758,27 +758,18 @@ struct zone * zone_for_pfn_range(int online_type, int nid, unsigned start_pfn,
 	return default_zone_for_pfn(nid, start_pfn, nr_pages);
 }
 
-int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_type)
+int __ref online_pages(unsigned long pfn, unsigned long nr_pages,
+		       int online_type, int nid)
 {
 	unsigned long flags;
 	unsigned long onlined_pages = 0;
 	struct zone *zone;
 	int need_zonelists_rebuild = 0;
-	int nid;
 	int ret;
 	struct memory_notify arg;
-	struct memory_block *mem;
 
 	mem_hotplug_begin();
 
-	/*
-	 * We can't use pfn_to_nid() because nid might be stored in struct page
-	 * which is not yet initialized. Instead, we find nid from memory block.
-	 */
-	mem = find_memory_block(__pfn_to_section(pfn));
-	nid = mem->nid;
-	put_device(&mem->dev);
-
 	/* associate pfn range with the zone */
 	zone = zone_for_pfn_range(online_type, nid, pfn, nr_pages);
 	move_pfn_range_to_zone(zone, pfn, nr_pages, NULL);
-- 
2.24.1