--- a/hotspot/src/share/vm/utilities/globalDefinitions.cpp	Mon Jan 18 19:10:32 2016 +0100
+++ b/hotspot/src/share/vm/utilities/globalDefinitions.cpp	Tue Jan 19 11:00:29 2016 +0100
@@ -357,6 +357,11 @@
 }
 
 #ifndef PRODUCT
+// For unit testing only
+class GlobalDefinitions {
+public:
+  static void test_globals();
+};
 
 void GlobalDefinitions::test_globals() {
   intptr_t page_sizes[] = { os::vm_page_size(), 4096, 8192, 65536, 2*1024*1024 };
@@ -384,4 +389,8 @@
   }
 }
 
+void GlobalDefinitions_test() {
+  GlobalDefinitions::test_globals();
+}
+
 #endif // PRODUCT