*** old/src/share/vm/gc_implementation/g1/vm_operations_g1.cpp	Tue Aug 20 21:45:08 2013
--- new/src/share/vm/gc_implementation/g1/vm_operations_g1.cpp	Tue Aug 20 21:45:08 2013

*** 68,77 ****
--- 68,80 ----
      _should_retry_gc(false),
      _old_marking_cycles_completed_before(0) {
    guarantee(target_pause_time_ms > 0.0,
              err_msg("target_pause_time_ms = %1.6lf should be positive",
                      target_pause_time_ms));
+   guarantee(word_size == 0 ||
+       (gc_cause == GCCause::_allocation_failure || gc_cause == GCCause::_g1_humongous_allocation),
+       "we can only request an allocation if the GC cause is for a failed allocation");
    _gc_cause = gc_cause;
  }
  
  bool VM_G1IncCollectionPause::doit_prologue() {
    bool res = VM_GC_Operation::doit_prologue();