8065749: [TESTBUG]: gc/arguments/TestG1HeapRegionSize.java fails at nightly

Reviewed-by: brutisso

test/gc/arguments/TestG1HeapRegionSize.java

 /*
-* Copyright (c) 2013, 2014, Oracle and/or its affiliates. All rights reserved.
+* Copyright (c) 2013, 2018, 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
@@ -25,12 +25,11 @@
  * @test TestG1HeapRegionSize
  * @key gc
  * @bug 8021879
- * @requires vm.gc=="G1" | vm.gc=="null"
  * @summary Verify that the flag G1HeapRegionSize is updated properly
  * @run main/othervm -Xmx64m TestG1HeapRegionSize 1048576
- * @run main/othervm -XX:G1HeapRegionSize=2m -Xmx64m -XX:+UseG1GC TestG1HeapRegionSize 2097152
- * @run main/othervm -XX:G1HeapRegionSize=3m -Xmx64m -XX:+UseG1GC TestG1HeapRegionSize 2097152
- * @run main/othervm -XX:G1HeapRegionSize=64m -Xmx256m -XX:+UseG1GC TestG1HeapRegionSize 33554432
+ * @run main/othervm -XX:G1HeapRegionSize=2m -Xmx64m TestG1HeapRegionSize 2097152
+ * @run main/othervm -XX:G1HeapRegionSize=3m -Xmx64m TestG1HeapRegionSize 2097152
+ * @run main/othervm -XX:G1HeapRegionSize=64m -Xmx256m TestG1HeapRegionSize 33554432
  */
 
 import sun.management.ManagementFactoryHelper;
@@ -43,7 +42,13 @@ public class TestG1HeapRegionSize {
     HotSpotDiagnosticMXBean diagnostic = ManagementFactoryHelper.getDiagnosticMXBean();
 
     String expectedValue = getExpectedValue(args);
-    VMOption option = diagnostic.getVMOption("G1HeapRegionSize");
+    VMOption option = diagnostic.getVMOption("UseG1GC");
+    if (option.getValue().equals("false")) {
+      System.out.println("Skipping this test. It is only a G1 test.");
+      return;
+    }
+
+    option = diagnostic.getVMOption("G1HeapRegionSize");
     if (!expectedValue.equals(option.getValue())) {
       throw new RuntimeException("Wrong value for G1HeapRegionSize. Expected " + expectedValue + " but got " + option.getValue());
     }