diff -r f0312c7d5b37 -r ba6c248cae19 src/hotspot/share/gc/shared/gcConfiguration.cpp
--- a/src/hotspot/share/gc/shared/gcConfiguration.cpp	Wed Nov 13 11:21:15 2019 +0100
+++ b/src/hotspot/share/gc/shared/gcConfiguration.cpp	Wed Nov 13 11:37:29 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -41,10 +41,6 @@
     return ParallelScavenge;
   }
 
-  if (UseConcMarkSweepGC) {
-    return ParNew;
-  }
-
   if (UseZGC || UseShenandoahGC) {
     return NA;
   }
@@ -57,10 +53,6 @@
     return G1Old;
   }
 
-  if (UseConcMarkSweepGC) {
-    return ConcurrentMarkSweep;
-  }
-
   if (UseParallelOldGC) {
     return ParallelOld;
   }