diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index a5b1713..a1a210d 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -471,6 +471,8 @@
 
 #define ptep_clear_flush_young_notify ptep_clear_flush_young
 #define pmdp_clear_flush_young_notify pmdp_clear_flush_young
+#define ptep_clear_young_notify ptep_test_and_clear_young
+#define pmdp_clear_young_notify pmdp_test_and_clear_young
 #define	ptep_clear_flush_notify ptep_clear_flush
 #define pmdp_huge_clear_flush_notify pmdp_huge_clear_flush
 #define pmdp_huge_get_and_clear_notify pmdp_huge_get_and_clear
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 41c9384..416509e 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -109,6 +109,10 @@
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 	PG_compound_lock,
 #endif
+#if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT)
+	PG_young,
+	PG_idle,
+#endif
 	__NR_PAGEFLAGS,
 
 	/* Filesystems */
@@ -289,6 +293,13 @@
 #define __PG_HWPOISON 0
 #endif
 
+#if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT)
+TESTPAGEFLAG(Young, young)
+SETPAGEFLAG(Young, young)
+TESTCLEARFLAG(Young, young)
+PAGEFLAG(Idle, idle)
+#endif
+
 /*
  * On an anonymous page mapped into a user virtual memory area,
  * page->mapping points to its anon_vma, not to a struct address_space;
diff --git a/include/linux/page_ext.h b/include/linux/page_ext.h
index c42981c..17f118a 100644
--- a/include/linux/page_ext.h
+++ b/include/linux/page_ext.h
@@ -26,6 +26,10 @@
 	PAGE_EXT_DEBUG_POISON,		/* Page is poisoned */
 	PAGE_EXT_DEBUG_GUARD,
 	PAGE_EXT_OWNER,
+#if defined(CONFIG_IDLE_PAGE_TRACKING) && !defined(CONFIG_64BIT)
+	PAGE_EXT_YOUNG,
+	PAGE_EXT_IDLE,
+#endif
 };
 
 /*
diff --git a/include/linux/page_idle.h b/include/linux/page_idle.h
new file mode 100644
index 0000000..bf268fa
--- /dev/null
+++ b/include/linux/page_idle.h
@@ -0,0 +1,110 @@
+#ifndef _LINUX_MM_PAGE_IDLE_H
+#define _LINUX_MM_PAGE_IDLE_H
+
+#include <linux/bitops.h>
+#include <linux/page-flags.h>
+#include <linux/page_ext.h>
+
+#ifdef CONFIG_IDLE_PAGE_TRACKING
+
+#ifdef CONFIG_64BIT
+static inline bool page_is_young(struct page *page)
+{
+	return PageYoung(page);
+}
+
+static inline void set_page_young(struct page *page)
+{
+	SetPageYoung(page);
+}
+
+static inline bool test_and_clear_page_young(struct page *page)
+{
+	return TestClearPageYoung(page);
+}
+
+static inline bool page_is_idle(struct page *page)
+{
+	return PageIdle(page);
+}
+
+static inline void set_page_idle(struct page *page)
+{
+	SetPageIdle(page);
+}
+
+static inline void clear_page_idle(struct page *page)
+{
+	ClearPageIdle(page);
+}
+#else /* !CONFIG_64BIT */
+/*
+ * If there is not enough space to store Idle and Young bits in page flags, use
+ * page ext flags instead.
+ */
+extern struct page_ext_operations page_idle_ops;
+
+static inline bool page_is_young(struct page *page)
+{
+	return test_bit(PAGE_EXT_YOUNG, &lookup_page_ext(page)->flags);
+}
+
+static inline void set_page_young(struct page *page)
+{
+	set_bit(PAGE_EXT_YOUNG, &lookup_page_ext(page)->flags);
+}
+
+static inline bool test_and_clear_page_young(struct page *page)
+{
+	return test_and_clear_bit(PAGE_EXT_YOUNG,
+				  &lookup_page_ext(page)->flags);
+}
+
+static inline bool page_is_idle(struct page *page)
+{
+	return test_bit(PAGE_EXT_IDLE, &lookup_page_ext(page)->flags);
+}
+
+static inline void set_page_idle(struct page *page)
+{
+	set_bit(PAGE_EXT_IDLE, &lookup_page_ext(page)->flags);
+}
+
+static inline void clear_page_idle(struct page *page)
+{
+	clear_bit(PAGE_EXT_IDLE, &lookup_page_ext(page)->flags);
+}
+#endif /* CONFIG_64BIT */
+
+#else /* !CONFIG_IDLE_PAGE_TRACKING */
+
+static inline bool page_is_young(struct page *page)
+{
+	return false;
+}
+
+static inline void set_page_young(struct page *page)
+{
+}
+
+static inline bool test_and_clear_page_young(struct page *page)
+{
+	return false;
+}
+
+static inline bool page_is_idle(struct page *page)
+{
+	return false;
+}
+
+static inline void set_page_idle(struct page *page)
+{
+}
+
+static inline void clear_page_idle(struct page *page)
+{
+}
+
+#endif /* CONFIG_IDLE_PAGE_TRACKING */
+
+#endif /* _LINUX_MM_PAGE_IDLE_H */