--- a/src/hotspot/share/gc/parallel/psMarkSweep.cpp	Tue May 08 09:57:45 2018 +0200
+++ b/src/hotspot/share/gc/parallel/psMarkSweep.cpp	Tue May 08 10:01:29 2018 +0200
@@ -260,11 +260,7 @@
     DerivedPointerTable::update_pointers();
 #endif
 
-    ReferenceProcessorPhaseTimes pt(_gc_timer, ref_processor()->num_queues());
-
-    ref_processor()->enqueue_discovered_references(NULL, &pt);
-
-    pt.print_enqueue_phase();
+    assert(!ref_processor()->discovery_enabled(), "Should have been disabled earlier");
 
     // Update time of last GC
     reset_millis_since_last_gc();