1 files changed, 2 insertions, 1 deletions

diff --git a/mm/memory.c b/mm/memory.c
index 7a61a11f1867..1a435b81876c 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -45,6 +45,7 @@
 #include <linux/swap.h>
 #include <linux/highmem.h>
 #include <linux/pagemap.h>
+#include <linux/ksm.h>
 #include <linux/rmap.h>
 #include <linux/module.h>
 #include <linux/delayacct.h>
@@ -1974,7 +1975,7 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
          * Take out anonymous pages first, anonymous shared vmas are
          * not dirty accountable.
          */
-        if (PageAnon(old_page)) {
+        if (PageAnon(old_page) && !PageKsm(old_page)) {
                 if (!trylock_page(old_page)) {
                         page_cache_get(old_page);
                         pte_unmap_unlock(page_table, ptl);