diff -r 3115100553b5 -r 547f81740344 src/share/vm/runtime/globals.hpp
--- a/src/share/vm/runtime/globals.hpp	Wed Dec 02 20:32:27 2009 -0500
+++ b/src/share/vm/runtime/globals.hpp	Fri Dec 11 11:09:49 2009 -0800
@@ -2554,6 +2554,9 @@
           "Include miscellaneous runtime verifications in nmethod code; "   \
           "default off because it disturbs nmethod size heuristics")        \
                                                                             \
+  notproduct(bool, CrashGCForDumpingJavaThread, false,                      \
+          "Manually make GC thread crash then dump java stack trace;  "     \
+          "Test only")                                                      \
                                                                             \
   /* compilation */                                                         \
   product(bool, UseCompiler, true,                                          \