diff -r 97fbf5beff7b -r 8b10f48633dc src/share/vm/gc_implementation/parNew/parNewGeneration.cpp
--- a/src/share/vm/gc_implementation/parNew/parNewGeneration.cpp	Thu Sep 16 13:45:55 2010 -0700
+++ b/src/share/vm/gc_implementation/parNew/parNewGeneration.cpp	Mon Sep 20 14:38:38 2010 -0700
@@ -1533,3 +1533,7 @@
 const char* ParNewGeneration::name() const {
   return "par new generation";
 }
+
+bool ParNewGeneration::in_use() {
+  return UseParNewGC && ParallelGCThreads > 0;
+}