--- a/src/hotspot/share/gc/g1/g1DirtyCardQueue.hpp	Fri Aug 30 00:03:10 2019 +0200
+++ b/src/hotspot/share/gc/g1/g1DirtyCardQueue.hpp	Thu Aug 29 18:35:52 2019 -0400
@@ -66,14 +66,14 @@
 };
 
 class G1DirtyCardQueueSet: public PtrQueueSet {
-  Monitor* _cbl_mon;  // Protects the fields below.
+  Monitor* _cbl_mon;  // Protects the list and count members.
   BufferNode* _completed_buffers_head;
   BufferNode* _completed_buffers_tail;
 
-  // Number of actual entries in the list of completed buffers.
-  volatile size_t _num_entries_in_completed_buffers;
+  // Number of actual cards in the list of completed buffers.
+  volatile size_t _num_cards;
 
-  size_t _process_completed_buffers_threshold;
+  size_t _process_cards_threshold;
   volatile bool _process_completed_buffers;
 
   // If true, notify_all on _cbl_mon when the threshold is reached.
@@ -112,11 +112,11 @@
 
   bool mut_process_buffer(BufferNode* node);
 
-  // If the queue contains more buffers than configured here, the
-  // mutator must start doing some of the concurrent refinement work,
-  size_t _max_completed_buffers;
-  size_t _completed_buffers_padding;
-  static const size_t MaxCompletedBuffersUnlimited = SIZE_MAX;
+  // If the queue contains more cards than configured here, the
+  // mutator must start doing some of the concurrent refinement work.
+  size_t _max_cards;
+  size_t _max_cards_padding;
+  static const size_t MaxCardsUnlimited = SIZE_MAX;
 
   G1FreeIdSet* _free_ids;
 
@@ -150,31 +150,26 @@
   // return a completed buffer from the list.  Otherwise, return NULL.
   BufferNode* get_completed_buffer(size_t stop_at = 0);
 
-  // The number of buffers in the list. Derived as an approximation from the number
-  // of entries in the buffers. Racy.
-  size_t num_completed_buffers() const {
-    return (num_entries_in_completed_buffers() + buffer_size() - 1) / buffer_size();
-  }
-  // The number of entries in completed buffers. Read without synchronization.
-  size_t num_entries_in_completed_buffers() const { return _num_entries_in_completed_buffers; }
+  // The number of cards in completed buffers. Read without synchronization.
+  size_t num_cards() const { return _num_cards; }
 
-  // Verify that _num_entries_in_completed_buffers is equal to the sum of actual entries
+  // Verify that _num_cards is equal to the sum of actual cards
   // in the completed buffers.
-  void verify_num_entries_in_completed_buffers() const NOT_DEBUG_RETURN;
+  void verify_num_cards() const NOT_DEBUG_RETURN;
 
   bool process_completed_buffers() { return _process_completed_buffers; }
   void set_process_completed_buffers(bool x) { _process_completed_buffers = x; }
 
-  // Get/Set the number of completed buffers that triggers log processing.
-  // Log processing should be done when the number of buffers exceeds the
+  // Get/Set the number of cards that triggers log processing.
+  // Log processing should be done when the number of cards exceeds the
   // threshold.
-  void set_process_completed_buffers_threshold(size_t sz) {
-    _process_completed_buffers_threshold = sz;
+  void set_process_cards_threshold(size_t sz) {
+    _process_cards_threshold = sz;
   }
-  size_t process_completed_buffers_threshold() const {
-    return _process_completed_buffers_threshold;
+  size_t process_cards_threshold() const {
+    return _process_cards_threshold;
   }
-  static const size_t ProcessCompletedBuffersThresholdNever = SIZE_MAX;
+  static const size_t ProcessCardsThresholdNever = SIZE_MAX;
 
   // Notify the consumer if the number of buffers crossed the threshold
   void notify_if_necessary();
@@ -196,18 +191,18 @@
   // If any threads have partial logs, add them to the global list of logs.
   void concatenate_logs();
 
-  void set_max_completed_buffers(size_t m) {
-    _max_completed_buffers = m;
+  void set_max_cards(size_t m) {
+    _max_cards = m;
   }
-  size_t max_completed_buffers() const {
-    return _max_completed_buffers;
+  size_t max_cards() const {
+    return _max_cards;
   }
 
-  void set_completed_buffers_padding(size_t padding) {
-    _completed_buffers_padding = padding;
+  void set_max_cards_padding(size_t padding) {
+    _max_cards_padding = padding;
   }
-  size_t completed_buffers_padding() const {
-    return _completed_buffers_padding;
+  size_t max_cards_padding() const {
+    return _max_cards_padding;
   }
 
   jint processed_buffers_mut() {