[PATCH 2/4] mm/thp: fix node page state in split_huge_page_to_list()

[Song Liu]

From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>

Make sure split_huge_page_to_list() handle the state of shmem THP and
file THP properly.

Fixes: 60fbf0ab5da1 ("mm,thp: stats for file backed THP")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Tested-by: Song Liu <songliubraving@xxxxxx>
Signed-off-by: Song Liu <songliubraving@xxxxxx>
---
 mm/huge_memory.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index c5cb6dcd6c69..13cc93785006 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2789,8 +2789,13 @@ int split_huge_page_to_list(struct page *page, struct list_head *list)
 			ds_queue->split_queue_len--;
 			list_del(page_deferred_list(head));
 		}
-		if (mapping)
-			__dec_node_page_state(page, NR_SHMEM_THPS);
+		if (mapping) {
+			if (PageSwapBacked(page))
+				__dec_node_page_state(page, NR_SHMEM_THPS);
+			else
+				__dec_node_page_state(page, NR_FILE_THPS);
+		}
+
 		spin_unlock(&ds_queue->split_queue_lock);
 		__split_huge_page(page, list, end, flags);
 		if (PageSwapCache(head)) {
-- 
2.17.1