[PATCH v2] mm/sparse: set section nid for hot-add memory

[Wei Yang <richardw.yang@linux.intel.com>]

In case of NODE_NOT_IN_PAGE_FLAGS is set, we store section's node id in
section_to_node_table[]. While for hot-add memory, this is missed.
Without this information, page_to_nid() may not give the right node id.

BTW, current online_pages works because it leverages nid in memory_block.
But the granularity of node id should be mem_section wide.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>

---
v2:
  * specify the case NODE_NOT_IN_PAGE_FLAGS is effected.
  * list one of the victim page_to_nid()

---
 mm/sparse.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mm/sparse.c b/mm/sparse.c
index 4012d7f50010..48fa16038cf5 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -733,6 +733,7 @@ int __meminit sparse_add_one_section(int nid, unsigned long start_pfn,
 	 */
 	page_init_poison(memmap, sizeof(struct page) * PAGES_PER_SECTION);
 
+	set_section_nid(section_nr, nid);
 	section_mark_present(ms);
 	sparse_init_one_section(ms, section_nr, memmap, usemap);
 
-- 
2.19.1