diff --git a/include/linux/sched.h b/include/linux/sched.h
index 292cb57..1c30bc3 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -249,13 +249,47 @@
 extern void arch_unmap_area(struct mm_struct *, unsigned long);
 extern void arch_unmap_area_topdown(struct mm_struct *, unsigned long);
 
+#if NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS
+/*
+ * The mm counters are not protected by its page_table_lock,
+ * so must be incremented atomically.
+ */
+#ifdef ATOMIC64_INIT
+#define set_mm_counter(mm, member, value) atomic64_set(&(mm)->_##member, value)
+#define get_mm_counter(mm, member) ((unsigned long)atomic64_read(&(mm)->_##member))
+#define add_mm_counter(mm, member, value) atomic64_add(value, &(mm)->_##member)
+#define inc_mm_counter(mm, member) atomic64_inc(&(mm)->_##member)
+#define dec_mm_counter(mm, member) atomic64_dec(&(mm)->_##member)
+typedef atomic64_t mm_counter_t;
+#else /* !ATOMIC64_INIT */
+/*
+ * The counters wrap back to 0 at 2^32 * PAGE_SIZE,
+ * that is, at 16TB if using 4kB page size.
+ */
+#define set_mm_counter(mm, member, value) atomic_set(&(mm)->_##member, value)
+#define get_mm_counter(mm, member) ((unsigned long)atomic_read(&(mm)->_##member))
+#define add_mm_counter(mm, member, value) atomic_add(value, &(mm)->_##member)
+#define inc_mm_counter(mm, member) atomic_inc(&(mm)->_##member)
+#define dec_mm_counter(mm, member) atomic_dec(&(mm)->_##member)
+typedef atomic_t mm_counter_t;
+#endif /* !ATOMIC64_INIT */
+
+#else  /* NR_CPUS < CONFIG_SPLIT_PTLOCK_CPUS */
+/*
+ * The mm counters are protected by its page_table_lock,
+ * so can be incremented directly.
+ */
 #define set_mm_counter(mm, member, value) (mm)->_##member = (value)
 #define get_mm_counter(mm, member) ((mm)->_##member)
 #define add_mm_counter(mm, member, value) (mm)->_##member += (value)
 #define inc_mm_counter(mm, member) (mm)->_##member++
 #define dec_mm_counter(mm, member) (mm)->_##member--
-#define get_mm_rss(mm) ((mm)->_file_rss + (mm)->_anon_rss)
+typedef unsigned long mm_counter_t;
 
+#endif /* NR_CPUS < CONFIG_SPLIT_PTLOCK_CPUS */
+
+#define get_mm_rss(mm)					\
+	(get_mm_counter(mm, file_rss) + get_mm_counter(mm, anon_rss))
 #define update_hiwater_rss(mm)	do {			\
 	unsigned long _rss = get_mm_rss(mm);		\
 	if ((mm)->hiwater_rss < _rss)			\
@@ -266,8 +300,6 @@
 		(mm)->hiwater_vm = (mm)->total_vm;	\
 } while (0)
 
-typedef unsigned long mm_counter_t;
-
 struct mm_struct {
 	struct vm_area_struct * mmap;		/* list of VMAs */
 	struct rb_root mm_rb;
@@ -291,7 +323,9 @@
 						 * by mmlist_lock
 						 */
 
-	/* Special counters protected by the page_table_lock */
+	/* Special counters, in some configurations protected by the
+	 * page_table_lock, in other configurations by being atomic.
+	 */
 	mm_counter_t _file_rss;
 	mm_counter_t _anon_rss;