--- a/src/hotspot/share/runtime/mutexLocker.hpp	Tue Mar 20 15:38:00 2018 +0100
+++ b/src/hotspot/share/runtime/mutexLocker.hpp	Mon Mar 26 09:35:20 2018 -0400
@@ -137,6 +137,9 @@
 extern Mutex*   UnsafeJlong_lock;                // provides Unsafe atomic updates to jlongs on platforms that don't support cx8
 #endif
 
+extern Mutex*   MetaspaceExpand_lock;            // protects Metaspace virtualspace and chunk expansions
+
+
 // A MutexLocker provides mutual exclusion with respect to a given mutex
 // for the scope which contains the locker.  The lock is an OS lock, not
 // an object lock, and the two do not interoperate.  Do not use Mutex-based