diff --git a/src/hotspot/share/gc/g1/g1Analytics.cpp b/src/hotspot/share/gc/g1/g1Analytics.cpp
index f1d032061dc..5809bfa2b6c 100644
--- a/src/hotspot/share/gc/g1/g1Analytics.cpp
+++ b/src/hotspot/share/gc/g1/g1Analytics.cpp
@@ -83,7 +83,7 @@ G1Analytics::G1Analytics(const G1Predictions* predictor) :
     _cost_per_code_root_ms_seq(TruncatedSeqLength),
     _cost_per_byte_copied_ms_seq(TruncatedSeqLength),
     _pending_cards_seq(TruncatedSeqLength),
-    _rs_length_seq(TruncatedSeqLength),
+    _card_rs_length_seq(TruncatedSeqLength),
     _code_root_rs_length_seq(TruncatedSeqLength),
     _constant_other_time_ms_seq(TruncatedSeqLength),
     _young_other_cost_per_region_ms_seq(TruncatedSeqLength),
@@ -105,7 +105,7 @@ G1Analytics::G1Analytics(const G1Predictions* predictor) :
 
   _card_scan_to_merge_ratio_seq.set_initial(young_card_scan_to_merge_ratio_defaults[index]);
   _cost_per_card_scan_ms_seq.set_initial(young_only_cost_per_card_scan_ms_defaults[index]);
-  _rs_length_seq.set_initial(0);
+  _card_rs_length_seq.set_initial(0);
   _code_root_rs_length_seq.set_initial(0);
   _cost_per_byte_copied_ms_seq.set_initial(cost_per_byte_ms_defaults[index]);
 
@@ -217,8 +217,8 @@ void G1Analytics::report_pending_cards(double pending_cards, bool for_young_only
   _pending_cards_seq.add(pending_cards, for_young_only_phase);
 }
 
-void G1Analytics::report_rs_length(double rs_length, bool for_young_only_phase) {
-  _rs_length_seq.add(rs_length, for_young_only_phase);
+void G1Analytics::report_card_rs_length(double card_rs_length, bool for_young_only_phase) {
+  _card_rs_length_seq.add(card_rs_length, for_young_only_phase);
 }
 
 void G1Analytics::report_code_root_rs_length(double code_root_rs_length, bool for_young_only_phase) {
@@ -245,8 +245,8 @@ size_t G1Analytics::predict_dirtied_cards_in_thread_buffers() const {
   return predict_size(&_dirtied_cards_in_thread_buffers_seq);
 }
 
-size_t G1Analytics::predict_scan_card_num(size_t rs_length, bool for_young_only_phase) const {
-  return rs_length * predict_in_unit_interval(&_card_scan_to_merge_ratio_seq, for_young_only_phase);
+size_t G1Analytics::predict_scan_card_num(size_t card_rs_length, bool for_young_only_phase) const {
+  return card_rs_length * predict_in_unit_interval(&_card_scan_to_merge_ratio_seq, for_young_only_phase);
 }
 
 double G1Analytics::predict_card_merge_time_ms(size_t card_num, bool for_young_only_phase) const {
@@ -285,8 +285,8 @@ double G1Analytics::predict_cleanup_time_ms() const {
   return predict_zero_bounded(&_concurrent_mark_cleanup_times_ms);
 }
 
-size_t G1Analytics::predict_rs_length(bool for_young_only_phase) const {
-  return predict_size(&_rs_length_seq, for_young_only_phase);
+size_t G1Analytics::predict_card_rs_length(bool for_young_only_phase) const {
+  return predict_size(&_card_rs_length_seq, for_young_only_phase);
 }
 
 size_t G1Analytics::predict_code_root_rs_length(bool for_young_only_phase) const {
diff --git a/src/hotspot/share/gc/g1/g1Analytics.hpp b/src/hotspot/share/gc/g1/g1Analytics.hpp
index fa9bb59bb7a..d4c6463b486 100644
--- a/src/hotspot/share/gc/g1/g1Analytics.hpp
+++ b/src/hotspot/share/gc/g1/g1Analytics.hpp
@@ -63,7 +63,7 @@ class G1Analytics: public CHeapObj<mtGC> {
   G1PhaseDependentSeq _cost_per_byte_copied_ms_seq;
 
   G1PhaseDependentSeq _pending_cards_seq;
-  G1PhaseDependentSeq _rs_length_seq;
+  G1PhaseDependentSeq _card_rs_length_seq;
   G1PhaseDependentSeq _code_root_rs_length_seq;
 
   TruncatedSeq _constant_other_time_ms_seq;
@@ -132,13 +132,12 @@ public:
   void report_cost_per_card_merge_ms(double cost_per_card_ms, bool for_young_only_phase);
   void report_cost_per_code_root_scan_ms(double cost_per_code_root_ms, bool for_young_only_phase);
   void report_card_scan_to_merge_ratio(double cards_per_entry_ratio, bool for_young_only_phase);
-  void report_rs_length_diff(double rs_length_diff, bool for_young_only_phase);
   void report_cost_per_byte_ms(double cost_per_byte_ms, bool for_young_only_phase);
   void report_young_other_cost_per_region_ms(double other_cost_per_region_ms);
   void report_non_young_other_cost_per_region_ms(double other_cost_per_region_ms);
   void report_constant_other_time_ms(double constant_other_time_ms);
   void report_pending_cards(double pending_cards, bool for_young_only_phase);
-  void report_rs_length(double rs_length, bool for_young_only_phase);
+  void report_card_rs_length(double card_rs_length, bool for_young_only_phase);
   void report_code_root_rs_length(double code_root_rs_length, bool for_young_only_phase);
 
   double predict_alloc_rate_ms() const;
@@ -148,9 +147,9 @@ public:
   double predict_dirtied_cards_rate_ms() const;
   size_t predict_dirtied_cards_in_thread_buffers() const;
 
-  // Predict how many of the given remembered set of length rs_length will add to
+  // Predict how many of the given remembered set of length card_rs_length will add to
   // the number of total cards scanned.
-  size_t predict_scan_card_num(size_t rs_length, bool for_young_only_phase) const;
+  size_t predict_scan_card_num(size_t card_rs_length, bool for_young_only_phase) const;
 
   double predict_card_merge_time_ms(size_t card_num, bool for_young_only_phase) const;
   double predict_card_scan_time_ms(size_t card_num, bool for_young_only_phase) const;
@@ -169,7 +168,7 @@ public:
 
   double predict_cleanup_time_ms() const;
 
-  size_t predict_rs_length(bool for_young_only_phase) const;
+  size_t predict_card_rs_length(bool for_young_only_phase) const;
   size_t predict_code_root_rs_length(bool for_young_only_phase) const;
   size_t predict_pending_cards(bool for_young_only_phase) const;
 
diff --git a/src/hotspot/share/gc/g1/g1ConcurrentRefine.cpp b/src/hotspot/share/gc/g1/g1ConcurrentRefine.cpp
index 9aab42afc45..aebdd2c43f5 100644
--- a/src/hotspot/share/gc/g1/g1ConcurrentRefine.cpp
+++ b/src/hotspot/share/gc/g1/g1ConcurrentRefine.cpp
@@ -279,21 +279,21 @@ uint64_t G1ConcurrentRefine::adjust_threads_wait_ms() const {
 
 class G1ConcurrentRefine::RemSetSamplingClosure : public HeapRegionClosure {
   G1CollectionSet* _cset;
-  size_t _sampled_rs_length;
+  size_t _sampled_card_rs_length;
   size_t _sampled_code_root_rs_length;
 
 public:
   explicit RemSetSamplingClosure(G1CollectionSet* cset) :
-    _cset(cset), _sampled_rs_length(0), _sampled_code_root_rs_length(0) {}
+    _cset(cset), _sampled_card_rs_length(0), _sampled_code_root_rs_length(0) {}
 
   bool do_heap_region(HeapRegion* r) override {
     HeapRegionRemSet* rem_set = r->rem_set();
-    _sampled_rs_length += rem_set->occupied();
+    _sampled_card_rs_length += rem_set->occupied();
     _sampled_code_root_rs_length += rem_set->code_roots_list_length();
     return false;
   }
 
-  size_t sampled_rs_length() const { return _sampled_rs_length; }
+  size_t sampled_card_rs_length() const { return _sampled_card_rs_length; }
   size_t sampled_code_root_rs_length() const { return _sampled_code_root_rs_length; }
 };
 
@@ -314,7 +314,7 @@ void G1ConcurrentRefine::adjust_young_list_target_length() {
     G1CollectionSet* cset = G1CollectedHeap::heap()->collection_set();
     RemSetSamplingClosure cl{cset};
     cset->iterate(&cl);
-    _policy->revise_young_list_target_length(cl.sampled_rs_length(), cl.sampled_code_root_rs_length());
+    _policy->revise_young_list_target_length(cl.sampled_card_rs_length(), cl.sampled_code_root_rs_length());
   }
 }
 
diff --git a/src/hotspot/share/gc/g1/g1Policy.cpp b/src/hotspot/share/gc/g1/g1Policy.cpp
index 4990dd64217..33e8ad79754 100644
--- a/src/hotspot/share/gc/g1/g1Policy.cpp
+++ b/src/hotspot/share/gc/g1/g1Policy.cpp
@@ -70,7 +70,7 @@ G1Policy::G1Policy(STWGCTimer* gc_timer) :
   _reserve_regions(0),
   _young_gen_sizer(),
   _free_regions_at_end_of_collection(0),
-  _rs_length(0),
+  _card_rs_length(0),
   _pending_cards_at_gc_start(0),
   _concurrent_start_to_mixed(),
   _collection_set(nullptr),
@@ -189,20 +189,20 @@ void G1Policy::update_young_length_bounds() {
   assert(!Universe::is_fully_initialized() || SafepointSynchronize::is_at_safepoint(), "must be");
   bool for_young_only_phase = collector_state()->in_young_only_phase();
   update_young_length_bounds(_analytics->predict_pending_cards(for_young_only_phase),
-                             _analytics->predict_rs_length(for_young_only_phase),
+                             _analytics->predict_card_rs_length(for_young_only_phase),
                              _analytics->predict_code_root_rs_length(for_young_only_phase));
 }
 
-void G1Policy::update_young_length_bounds(size_t pending_cards, size_t rs_length, size_t code_root_rs_length) {
+void G1Policy::update_young_length_bounds(size_t pending_cards, size_t card_rs_length, size_t code_root_rs_length) {
   uint old_young_list_target_length = young_list_target_length();
 
-  uint new_young_list_desired_length = calculate_young_desired_length(pending_cards, rs_length, code_root_rs_length);
+  uint new_young_list_desired_length = calculate_young_desired_length(pending_cards, card_rs_length, code_root_rs_length);
   uint new_young_list_target_length = calculate_young_target_length(new_young_list_desired_length);
   uint new_young_list_max_length = calculate_young_max_length(new_young_list_target_length);
 
-  log_trace(gc, ergo, heap)("Young list length update: pending cards %zu rs_length %zu old target %u desired: %u target: %u max: %u",
+  log_trace(gc, ergo, heap)("Young list length update: pending cards %zu card_rs_length %zu old target %u desired: %u target: %u max: %u",
                             pending_cards,
-                            rs_length,
+                            card_rs_length,
                             old_young_list_target_length,
                             new_young_list_desired_length,
                             new_young_list_target_length,
@@ -236,7 +236,7 @@ void G1Policy::update_young_length_bounds(size_t pending_cards, size_t rs_length
 // This return value is only an expectation.
 //
 uint G1Policy::calculate_young_desired_length(size_t pending_cards,
-                                              size_t rs_length,
+                                              size_t card_rs_length,
                                               size_t code_root_rs_length) const {
   uint min_young_length_by_sizer = _young_gen_sizer.min_desired_young_length();
   uint max_young_length_by_sizer = _young_gen_sizer.max_desired_young_length();
@@ -270,7 +270,7 @@ uint G1Policy::calculate_young_desired_length(size_t pending_cards,
   if (use_adaptive_young_list_length()) {
     desired_eden_length_by_mmu = calculate_desired_eden_length_by_mmu();
 
-    double base_time_ms = predict_base_time_ms(pending_cards, rs_length, code_root_rs_length);
+    double base_time_ms = predict_base_time_ms(pending_cards, card_rs_length, code_root_rs_length);
     double retained_time_ms = predict_retained_regions_evac_time();
     double total_time_ms = base_time_ms + retained_time_ms;
 
@@ -553,13 +553,13 @@ G1GCPhaseTimes* G1Policy::phase_times() const {
   return _phase_times;
 }
 
-void G1Policy::revise_young_list_target_length(size_t rs_length, size_t code_root_rs_length) {
+void G1Policy::revise_young_list_target_length(size_t card_rs_length, size_t code_root_rs_length) {
   guarantee(use_adaptive_young_list_length(), "should not call this otherwise" );
 
   size_t thread_buffer_cards = _analytics->predict_dirtied_cards_in_thread_buffers();
   G1DirtyCardQueueSet& dcqs = G1BarrierSet::dirty_card_queue_set();
   size_t pending_cards = dcqs.num_cards() + thread_buffer_cards;
-  update_young_length_bounds(pending_cards, rs_length, code_root_rs_length);
+  update_young_length_bounds(pending_cards, card_rs_length, code_root_rs_length);
 }
 
 void G1Policy::record_full_collection_start() {
@@ -925,7 +925,7 @@ void G1Policy::record_young_collection_end(bool concurrent_operation_is_full_mar
     _analytics->report_constant_other_time_ms(constant_other_time_ms(pause_time_ms));
 
     _analytics->report_pending_cards((double)pending_cards_at_gc_start(), is_young_only_pause);
-    _analytics->report_rs_length((double)_rs_length, is_young_only_pause);
+    _analytics->report_card_rs_length((double)_card_rs_length, is_young_only_pause);
     _analytics->report_code_root_rs_length((double)total_code_roots_scanned, is_young_only_pause);
   }
 
@@ -1048,16 +1048,16 @@ void G1Policy::record_young_gc_pause_end(bool evacuation_failed) {
 }
 
 double G1Policy::predict_base_time_ms(size_t pending_cards,
-                                      size_t rs_length,
+                                      size_t card_rs_length,
                                       size_t code_root_rs_length) const {
   bool in_young_only_phase = collector_state()->in_young_only_phase();
 
-  size_t unique_cards_from_rs = _analytics->predict_scan_card_num(rs_length, in_young_only_phase);
+  size_t unique_cards_from_rs = _analytics->predict_scan_card_num(card_rs_length, in_young_only_phase);
   // Assume that all cards from the log buffers will be scanned, i.e. there are no
   // duplicates in that set.
   size_t effective_scanned_cards = unique_cards_from_rs + pending_cards;
 
-  double card_merge_time = _analytics->predict_card_merge_time_ms(pending_cards + rs_length, in_young_only_phase);
+  double card_merge_time = _analytics->predict_card_merge_time_ms(pending_cards + card_rs_length, in_young_only_phase);
   double card_scan_time = _analytics->predict_card_scan_time_ms(effective_scanned_cards, in_young_only_phase);
   double code_root_scan_time = _analytics->predict_code_root_scan_time_ms(code_root_rs_length, in_young_only_phase);
   double constant_other_time = _analytics->predict_constant_other_time_ms();
@@ -1065,10 +1065,10 @@ double G1Policy::predict_base_time_ms(size_t pending_cards,
 
   double total_time = card_merge_time + card_scan_time + code_root_scan_time + constant_other_time + survivor_evac_time;
 
-  log_trace(gc, ergo, heap)("Predicted base time: total %f lb_cards %zu rs_length %zu effective_scanned_cards %zu "
+  log_trace(gc, ergo, heap)("Predicted base time: total %f lb_cards %zu card_rs_length %zu effective_scanned_cards %zu "
                             "card_merge_time %f card_scan_time %f code_root_rs_length %zu code_root_scan_time %f "
                             "constant_other_time %f survivor_evac_time %f",
-                            total_time, pending_cards, rs_length, effective_scanned_cards,
+                            total_time, pending_cards, card_rs_length, effective_scanned_cards,
                             card_merge_time, card_scan_time, code_root_rs_length, code_root_scan_time,
                             constant_other_time, survivor_evac_time);
   return total_time;
@@ -1076,9 +1076,9 @@ double G1Policy::predict_base_time_ms(size_t pending_cards,
 
 double G1Policy::predict_base_time_ms(size_t pending_cards) const {
   bool for_young_only_phase = collector_state()->in_young_only_phase();
-  size_t rs_length = _analytics->predict_rs_length(for_young_only_phase);
+  size_t card_rs_length = _analytics->predict_card_rs_length(for_young_only_phase);
   size_t code_root_rs_length = _analytics->predict_code_root_rs_length(for_young_only_phase);
-  return predict_base_time_ms(pending_cards, rs_length, code_root_rs_length);
+  return predict_base_time_ms(pending_cards, card_rs_length, code_root_rs_length);
 }
 
 size_t G1Policy::predict_bytes_to_copy(HeapRegion* hr) const {
@@ -1112,11 +1112,11 @@ double G1Policy::predict_region_copy_time_ms(HeapRegion* hr, bool for_young_only
 }
 
 double G1Policy::predict_region_merge_scan_time(HeapRegion* hr, bool for_young_only_phase) const {
-  size_t rs_length = hr->rem_set()->occupied();
-  size_t scan_card_num = _analytics->predict_scan_card_num(rs_length, for_young_only_phase);
+  size_t card_rs_length = hr->rem_set()->occupied();
+  size_t scan_card_num = _analytics->predict_scan_card_num(card_rs_length, for_young_only_phase);
 
   return
-    _analytics->predict_card_merge_time_ms(rs_length, for_young_only_phase) +
+    _analytics->predict_card_merge_time_ms(card_rs_length, for_young_only_phase) +
     _analytics->predict_card_scan_time_ms(scan_card_num, for_young_only_phase);
 }
 
diff --git a/src/hotspot/share/gc/g1/g1Policy.hpp b/src/hotspot/share/gc/g1/g1Policy.hpp
index e478f7ebcdb..7ecfc4dd2f7 100644
--- a/src/hotspot/share/gc/g1/g1Policy.hpp
+++ b/src/hotspot/share/gc/g1/g1Policy.hpp
@@ -103,7 +103,7 @@ class G1Policy: public CHeapObj<mtGC> {
 
   uint _free_regions_at_end_of_collection;
 
-  size_t _rs_length;
+  size_t _card_rs_length;
 
   size_t _pending_cards_at_gc_start;
 
@@ -132,8 +132,8 @@ public:
     hr->install_surv_rate_group(_survivor_surv_rate_group);
   }
 
-  void record_rs_length(size_t rs_length) {
-    _rs_length = rs_length;
+  void record_card_rs_length(size_t card_rs_length) {
+    _card_rs_length = card_rs_length;
   }
 
   double predict_base_time_ms(size_t pending_cards) const;
@@ -142,7 +142,7 @@ private:
   // Base time contains handling remembered sets and constant other time of the
   // whole young gen, refinement buffers, and copying survivors.
   // Basically everything but copying eden regions.
-  double predict_base_time_ms(size_t pending_cards, size_t rs_length, size_t code_root_length) const;
+  double predict_base_time_ms(size_t pending_cards, size_t card_rs_length, size_t code_root_length) const;
 
   // Copy time for a region is copying live data.
   double predict_region_copy_time_ms(HeapRegion* hr, bool for_young_only_phase) const;
@@ -213,15 +213,14 @@ private:
   // If no parameters are passed, predict pending cards, card set remset length and
   // code root remset length using the prediction model.
   void update_young_length_bounds();
-  void update_young_length_bounds(size_t pending_cards, size_t rs_length, size_t code_root_rs_length);
+  void update_young_length_bounds(size_t pending_cards, size_t card_rs_length, size_t code_root_rs_length);
 
   // Calculate and return the minimum desired eden length based on the MMU target.
   uint calculate_desired_eden_length_by_mmu() const;
 
   // Calculate the desired eden length meeting the pause time goal.
-  // The parameters are: rs_length represents the prediction of how large the
-  // young RSet lengths will be, min_eden_length and max_eden_length are the bounds
-  // (inclusive) within eden can grow.
+  // Min_eden_length and max_eden_length are the bounds
+  // (inclusive) within which eden can grow.
   uint calculate_desired_eden_length_by_pause(double base_time_ms,
                                               uint min_eden_length,
                                               uint max_eden_length) const;
@@ -241,7 +240,7 @@ private:
 
   // Calculate desired young length based on current situation without taking actually
   // available free regions into account.
-  uint calculate_young_desired_length(size_t pending_cards, size_t rs_length, size_t code_root_rs_length) const;
+  uint calculate_young_desired_length(size_t pending_cards, size_t card_rs_length, size_t code_root_rs_length) const;
   // Limit the given desired young length to available free regions.
   uint calculate_young_target_length(uint desired_young_length) const;
   // The GCLocker might cause us to need more regions than the target. Calculate
@@ -304,7 +303,7 @@ public:
   // Check the current value of the young list RSet length and
   // compare it against the last prediction. If the current value is
   // higher, recalculate the young list target length prediction.
-  void revise_young_list_target_length(size_t rs_length, size_t code_root_rs_length);
+  void revise_young_list_target_length(size_t card_rs_length, size_t code_root_rs_length);
 
   // This should be called after the heap is resized.
   void record_new_heap_size(uint new_number_of_regions);
diff --git a/src/hotspot/share/gc/g1/g1YoungGCPostEvacuateTasks.cpp b/src/hotspot/share/gc/g1/g1YoungGCPostEvacuateTasks.cpp
index 798e6f3c604..02820869148 100644
--- a/src/hotspot/share/gc/g1/g1YoungGCPostEvacuateTasks.cpp
+++ b/src/hotspot/share/gc/g1/g1YoungGCPostEvacuateTasks.cpp
@@ -434,7 +434,7 @@ class FreeCSetStats {
   size_t _bytes_allocated_in_old_since_last_gc; // Size of young regions turned into old
   size_t _failure_used_words;  // Live size in failed regions
   size_t _failure_waste_words; // Wasted size in failed regions
-  size_t _rs_length;           // Remembered set size
+  size_t _card_rs_length;      // (Card Set) Remembered set size
   uint _regions_freed;         // Number of regions freed
 
 public:
@@ -444,7 +444,7 @@ public:
       _bytes_allocated_in_old_since_last_gc(0),
       _failure_used_words(0),
       _failure_waste_words(0),
-      _rs_length(0),
+      _card_rs_length(0),
       _regions_freed(0) { }
 
   void merge_stats(FreeCSetStats* other) {
@@ -454,7 +454,7 @@ public:
     _bytes_allocated_in_old_since_last_gc += other->_bytes_allocated_in_old_since_last_gc;
     _failure_used_words += other->_failure_used_words;
     _failure_waste_words += other->_failure_waste_words;
-    _rs_length += other->_rs_length;
+    _card_rs_length += other->_card_rs_length;
     _regions_freed += other->_regions_freed;
   }
 
@@ -468,7 +468,7 @@ public:
 
     G1Policy *policy = g1h->policy();
     policy->old_gen_alloc_tracker()->add_allocated_bytes_since_last_gc(_bytes_allocated_in_old_since_last_gc);
-    policy->record_rs_length(_rs_length);
+    policy->record_card_rs_length(_card_rs_length);
     policy->cset_regions_freed();
   }
 
@@ -495,8 +495,8 @@ public:
     _regions_freed += 1;
   }
 
-  void account_rs_length(HeapRegion* r) {
-    _rs_length += r->rem_set()->occupied();
+  void account_card_rs_length(HeapRegion* r) {
+    _card_rs_length += r->rem_set()->occupied();
   }
 };
 
@@ -617,7 +617,7 @@ public:
     JFREventForRegion event(r, _worker_id);
     TimerForRegion timer(timer_for_region(r));
 
-    stats()->account_rs_length(r);
+    stats()->account_card_rs_length(r);
 
     if (r->is_young()) {
       assert_tracks_surviving_words(r);