diff --git a/mm/migrate.c b/mm/migrate.c
index 666e4e6..14d0a6a 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -120,10 +120,10 @@
 
 		ptep = pte_offset_map(pmd, addr);
 
-		if (!is_swap_pte(*ptep)) {
-			pte_unmap(ptep);
-			goto out;
-		}
+		/*
+		 * Peek to check is_swap_pte() before taking ptlock?  No, we
+		 * can race mremap's move_ptes(), which skips anon_vma lock.
+		 */
 
 		ptl = pte_lockptr(mm, pmd);
 	}