diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index cbfab1e..cc2e7df 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -62,6 +62,16 @@
 				 unsigned long address);
 
 	/*
+	 * test_young is called to check the young/accessed bitflag in
+	 * the secondary pte. This is used to know if the page is
+	 * frequently used without actually clearing the flag or tearing
+	 * down the secondary mapping on the page.
+	 */
+	int (*test_young)(struct mmu_notifier *mn,
+			  struct mm_struct *mm,
+			  unsigned long address);
+
+	/*
 	 * change_pte is called in cases that pte mapping to page is changed:
 	 * for example, when ksm remaps pte to point to a new shared page.
 	 */
@@ -163,6 +173,8 @@
 extern void __mmu_notifier_release(struct mm_struct *mm);
 extern int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
 					  unsigned long address);
+extern int __mmu_notifier_test_young(struct mm_struct *mm,
+				     unsigned long address);
 extern void __mmu_notifier_change_pte(struct mm_struct *mm,
 				      unsigned long address, pte_t pte);
 extern void __mmu_notifier_invalidate_page(struct mm_struct *mm,
@@ -186,6 +198,14 @@
 	return 0;
 }
 
+static inline int mmu_notifier_test_young(struct mm_struct *mm,
+					  unsigned long address)
+{
+	if (mm_has_notifiers(mm))
+		return __mmu_notifier_test_young(mm, address);
+	return 0;
+}
+
 static inline void mmu_notifier_change_pte(struct mm_struct *mm,
 					   unsigned long address, pte_t pte)
 {
@@ -313,6 +333,12 @@
 	return 0;
 }
 
+static inline int mmu_notifier_test_young(struct mm_struct *mm,
+					  unsigned long address)
+{
+	return 0;
+}
+
 static inline void mmu_notifier_change_pte(struct mm_struct *mm,
 					   unsigned long address, pte_t pte)
 {