--- old/test/gc/arguments/TestInitialTenuringThreshold.java	2015-08-18 16:24:12.701799492 -0700
+++ new/test/gc/arguments/TestInitialTenuringThreshold.java	2015-08-18 16:24:12.617799494 -0700
@@ -39,6 +39,7 @@
 
   public static void runWithThresholds(int initial, int max, boolean shouldfail) throws Exception {
     ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
+      "-XX:+UseParallelGC",
       "-XX:InitialTenuringThreshold=" + String.valueOf(initial),
       "-XX:MaxTenuringThreshold=" + String.valueOf(max),
       "-version"