[patch 22/26] mm/thp: fix node page state in split_huge_page_to_list()

[patch 22/26] mm/thp: fix node page state in split_huge_page_to_list()

[akpm]

From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Subject: mm/thp: fix node page state in split_huge_page_to_list()

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

Link: http://lkml.kernel.org/r/20191017164223.2762148-3-songliubraving@fb.com
Fixes: 60fbf0ab5da1 ("mm,thp: stats for file backed THP")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Tested-by: Song Liu <songliubraving@fb.com>
Acked-by: Yang Shi <yang.shi@linux.alibaba.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/huge_memory.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

--- a/mm/huge_memory.c~mm-thp-fix-node-page-state-in-split_huge_page_to_list
+++ a/mm/huge_memory.c
@@ -2789,8 +2789,13 @@ int split_huge_page_to_list(struct page
 			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)) {
_