--- old/src/hotspot/share/gc/z/zHeap.hpp	2018-03-06 13:23:13.146137989 +0100
+++ new/src/hotspot/share/gc/z/zHeap.hpp	2018-03-06 13:23:12.975130647 +0100
@@ -105,6 +105,8 @@
   ZPageTableEntry* pagetable_addr() const;
 
   // Workers
+  uint nconcurrent_worker_threads() const;
+  uint nconcurrent_no_boost_worker_threads() const;
   void set_boost_worker_threads(bool boost);
   void worker_threads_do(ThreadClosure* tc) const;
   void print_worker_threads_on(outputStream* st) const;