--- old/src/hotspot/share/gc/g1/g1ConcurrentRefine.cpp	2020-01-16 01:05:12.436027044 -0500
+++ new/src/hotspot/share/gc/g1/g1ConcurrentRefine.cpp	2020-01-16 01:05:12.056006529 -0500
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -89,6 +89,11 @@
       }
     }
   }
+
+  if (num_max_threads > 0) {
+    G1BarrierSet::dirty_card_queue_set().set_primary_refinement_thread(_threads[0]);
+  }
+
   return JNI_OK;
 }
 
@@ -108,7 +113,7 @@
     _threads[worker_id] = create_refinement_thread(worker_id, false);
     thread_to_activate = _threads[worker_id];
   }
-  if (thread_to_activate != NULL && !thread_to_activate->is_active()) {
+  if (thread_to_activate != NULL) {
     thread_to_activate->activate();
   }
 }