--- old/src/hotspot/share/gc/g1/g1DirtyCardQueue.cpp	2019-08-28 20:08:16.783319692 -0400
+++ new/src/hotspot/share/gc/g1/g1DirtyCardQueue.cpp	2019-08-28 20:08:16.451301809 -0400
@@ -91,7 +91,7 @@
   _notify_when_complete(notify_when_complete),
   _max_completed_buffers(MaxCompletedBuffersUnlimited),
   _completed_buffers_padding(0),
-  _free_ids(NULL),
+  _free_ids(new G1FreeIdSet(0, num_par_ids())),
   _processed_buffers_mut(0),
   _processed_buffers_rs_thread(0)
 {
@@ -109,14 +109,10 @@
 }
 
 void G1DirtyCardQueueSet::initialize(Monitor* cbl_mon,
-                                     BufferNode::Allocator* allocator,
-                                     bool init_free_ids) {
+                                     BufferNode::Allocator* allocator) {
   PtrQueueSet::initialize(allocator);
   assert(_cbl_mon == NULL, "Init order issue?");
   _cbl_mon = cbl_mon;
-  if (init_free_ids) {
-    _free_ids = new G1FreeIdSet(0, num_par_ids());
-  }
 }
 
 void G1DirtyCardQueueSet::handle_zero_index_for_thread(Thread* t) {
@@ -291,8 +287,6 @@
 }
 
 bool G1DirtyCardQueueSet::mut_process_buffer(BufferNode* node) {
-  guarantee(_free_ids != NULL, "must be");
-
   uint worker_i = _free_ids->claim_par_id(); // temporarily claim an id
   G1RefineCardConcurrentlyClosure cl;
   bool result = apply_closure_to_buffer(&cl, node, worker_i);