diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index 980094a..b019ae6 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -164,6 +164,12 @@
 void page_unlock_anon_vma(struct anon_vma *anon_vma);
 int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma);
 
+/*
+ * Called by migrate.c to remove migration ptes, but might be used more later.
+ */
+int rmap_walk(struct page *page, int (*rmap_one)(struct page *,
+		struct vm_area_struct *, unsigned long, void *), void *arg);
+
 #else	/* !CONFIG_MMU */
 
 #define anon_vma_init()		do {} while (0)