--- old/src/hotspot/share/gc/g1/g1CollectorState.hpp	2020-07-07 10:35:51.543076335 +0200
+++ new/src/hotspot/share/gc/g1/g1CollectorState.hpp	2020-07-07 10:35:51.447074642 +0200
@@ -40,28 +40,28 @@
 
   // If _initiate_conc_mark_if_possible is set at the beginning of a
   // pause, it is a suggestion that the pause should start a marking
-  // cycle by doing the initial-mark work. However, it is possible
+  // cycle by doing the concurrent start work. However, it is possible
   // that the concurrent marking thread is still finishing up the
   // previous marking cycle (e.g., clearing the next marking
   // bitmap). If that is the case we cannot start a new cycle and
   // we'll have to wait for the concurrent marking thread to finish
   // what it is doing. In this case we will postpone the marking cycle
   // initiation decision for the next pause. When we eventually decide
-  // to start a cycle, we will set _in_initial_mark_gc which
-  // will stay true until the end of the initial-mark pause doing the
-  // initial-mark work.
-  volatile bool _in_initial_mark_gc;
+  // to start a cycle, we will set _in_concurrent_start_gc which
+  // will stay true until the end of the concurrent start pause doing the
+  // concurrent start work.
+  volatile bool _in_concurrent_start_gc;
 
   // At the end of a pause we check the heap occupancy and we decide
   // whether we will start a marking cycle during the next pause. If
   // we decide that we want to do that, set this parameter. This parameter will
   // stay set until the beginning of a subsequent pause (not necessarily
   // the next one) when we decide that we will indeed start a marking cycle and
-  // do the initial-mark work.
+  // do the concurrent start phase work.
   volatile bool _initiate_conc_mark_if_possible;
 
   // Marking or rebuilding remembered set work is in progress. Set from the end
-  // of the initial mark pause to the end of the Cleanup pause.
+  // of the concurrent start pause to the end of the Cleanup pause.
   bool _mark_or_rebuild_in_progress;
 
   // The next bitmap is currently being cleared or about to be cleared. TAMS and bitmap
@@ -76,7 +76,7 @@
     _in_young_only_phase(true),
     _in_young_gc_before_mixed(false),
 
-    _in_initial_mark_gc(false),
+    _in_concurrent_start_gc(false),
     _initiate_conc_mark_if_possible(false),
 
     _mark_or_rebuild_in_progress(false),
@@ -88,7 +88,7 @@
 
   // Pause setters
   void set_in_young_gc_before_mixed(bool v) { _in_young_gc_before_mixed = v; }
-  void set_in_initial_mark_gc(bool v) { _in_initial_mark_gc = v; }
+  void set_in_concurrent_start_gc(bool v) { _in_concurrent_start_gc = v; }
   void set_in_full_gc(bool v) { _in_full_gc = v; }
 
   void set_initiate_conc_mark_if_possible(bool v) { _initiate_conc_mark_if_possible = v; }
@@ -103,7 +103,7 @@
   // Specific pauses
   bool in_young_gc_before_mixed() const { return _in_young_gc_before_mixed; }
   bool in_full_gc() const { return _in_full_gc; }
-  bool in_initial_mark_gc() const { return _in_initial_mark_gc; }
+  bool in_concurrent_start_gc() const { return _in_concurrent_start_gc; }
 
   bool initiate_conc_mark_if_possible() const { return _initiate_conc_mark_if_possible; }
 
@@ -111,8 +111,8 @@
   bool clearing_next_bitmap() const { return _clearing_next_bitmap; }
 
   G1YCType yc_type() const {
-    if (in_initial_mark_gc()) {
-      return InitialMark;
+    if (in_concurrent_start_gc()) {
+      return ConcurrentStart;
     } else if (mark_or_rebuild_in_progress()) {
       return DuringMarkOrRebuild;
     } else if (in_young_only_phase()) {