diff -r 84acc04e14d2 -r f7b9bb98bb72 hotspot/src/share/vm/gc/g1/heapRegionManager.hpp
--- a/hotspot/src/share/vm/gc/g1/heapRegionManager.hpp	Wed Aug 02 15:59:33 2017 +0000
+++ b/hotspot/src/share/vm/gc/g1/heapRegionManager.hpp	Sat Jul 22 15:54:27 2017 -0400
@@ -130,7 +130,7 @@
   // Empty constructor, we'll initialize it with the initialize() method.
   HeapRegionManager() : _regions(), _heap_mapper(NULL), _num_committed(0),
                     _next_bitmap_mapper(NULL), _prev_bitmap_mapper(NULL), _bot_mapper(NULL),
-                    _allocated_heapregions_length(0), _available_map(),
+                    _allocated_heapregions_length(0), _available_map(mtGC),
                     _free_list("Free list", new MasterFreeRegionListMtSafeChecker())
   { }