src/share/vm/runtime/vm_version.cpp

@@ -273,11 +273,12 @@
 unsigned int Abstract_VM_Version::nof_parallel_worker_threads(
                                                       unsigned int num,
                                                       unsigned int den,
                                                       unsigned int switch_pt) {
   if (FLAG_IS_DEFAULT(ParallelGCThreads)) {
-    assert(ParallelGCThreads == 0, "Default ParallelGCThreads is not 0");
+    assert(_parallel_worker_threads_initialized ||
+           ParallelGCThreads == 0, "Default ParallelGCThreads is not 0");
     // For very large machines, there are diminishing returns
     // for large numbers of worker threads.  Instead of
     // hogging the whole system, use a fraction of the workers for every
     // processor after the first 8.  For example, on a 72 cpu machine
     // and a chosen fraction of 5/8

@@ -307,5 +308,17 @@
     }
     _parallel_worker_threads_initialized = true;
   }
   return _parallel_worker_threads;
 }
+
+void  Abstract_VM_Version::FinalParallelGCThreads_test() {
+  // This consistency check should only be made if the user has not set
+  // a value on the command line and a ergonomically determined value 
+  // is used (i.e., _parallel_worker_threads_initialized is true).
+  if (FLAG_IS_DEFAULT(ParallelGCThreads) && _parallel_worker_threads_initialized) {
+    assert(ParallelGCThreads == VM_Version::calc_parallel_worker_threads(),
+      "ParallelGCThreads %u is different than that calculated after full VM initialization %u.",
+              ParallelGCThreads, VM_Version::calc_parallel_worker_threads());
+  }
+}
+