--- a/src/hotspot/share/gc/shared/generation.hpp	Wed Nov 13 11:21:15 2019 +0100
+++ b/src/hotspot/share/gc/shared/generation.hpp	Wed Nov 13 11:37:29 2019 +0100
@@ -41,20 +41,13 @@
 //
 // Generation                      - abstract base class
 // - DefNewGeneration              - allocation area (copy collected)
-//   - ParNewGeneration            - a DefNewGeneration that is collected by
-//                                   several threads
 // - CardGeneration                 - abstract class adding offset array behavior
 //   - TenuredGeneration             - tenured (old object) space (markSweepCompact)
-//   - ConcurrentMarkSweepGeneration - Mostly Concurrent Mark Sweep Generation
-//                                       (Detlefs-Printezis refinement of
-//                                       Boehm-Demers-Schenker)
 //
-// The system configurations currently allowed are:
+// The system configuration currently allowed is:
 //
 //   DefNewGeneration + TenuredGeneration
 //
-//   ParNewGeneration + ConcurrentMarkSweepGeneration
-//
 
 class DefNewGeneration;
 class GCMemoryManager;
@@ -122,9 +115,7 @@
   // The set of possible generation kinds.
   enum Name {
     DefNew,
-    ParNew,
     MarkSweepCompact,
-    ConcurrentMarkSweep,
     Other
   };
 
@@ -156,7 +147,6 @@
   virtual size_t capacity() const = 0;  // The maximum number of object bytes the
                                         // generation can currently hold.
   virtual size_t used() const = 0;      // The number of used bytes in the gen.
-  virtual size_t used_stable() const;   // The number of used bytes for memory monitoring tools.
   virtual size_t free() const = 0;      // The number of free bytes in the gen.
 
   // Support for java.lang.Runtime.maxMemory(); see CollectedHeap.