--- old/src/hotspot/share/gc/shared/generation.cpp	2018-05-08 09:41:52.776810542 +0200
+++ new/src/hotspot/share/gc/shared/generation.cpp	2018-05-08 09:41:52.488801643 +0200
@@ -77,7 +77,8 @@
 void Generation::ref_processor_init() {
   assert(_ref_processor == NULL, "a reference processor already exists");
   assert(!_reserved.is_empty(), "empty generation?");
-  _ref_processor = new ReferenceProcessor(_reserved);    // a vanilla reference processor
+  _span_discoverer.set_span(_reserved);
+  _ref_processor = new ReferenceProcessor(&_span_discoverer);    // a vanilla reference processor
   if (_ref_processor == NULL) {
     vm_exit_during_initialization("Could not allocate ReferenceProcessor object");
   }