diff --git a/include/linux/mm.h b/include/linux/mm.h
index 3899395..7f693b2 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -971,7 +971,13 @@
 		*maxrss = hiwater_rss;
 }
 
+#if defined(SPLIT_RSS_COUNTING)
 void sync_mm_rss(struct task_struct *task, struct mm_struct *mm);
+#else
+static inline void sync_mm_rss(struct task_struct *task, struct mm_struct *mm)
+{
+}
+#endif
 
 /*
  * A callback you can register to apply pressure to ageable caches.