--- old/src/share/vm/runtime/arguments.cpp	Thu Aug 10 01:02:04 2017
+++ new/src/share/vm/runtime/arguments.cpp	Thu Aug 10 01:02:03 2017
@@ -4462,6 +4462,12 @@
 
   set_shared_spaces_flags();
 
+#if defined(SPARC)
+  if (FLAG_IS_DEFAULT(AssumeMP)) {
+    FLAG_SET_DEFAULT(AssumeMP, true);
+  }
+#endif 
+
   // Check the GC selections again.
   if (!check_gc_consistency()) {
     return JNI_EINVAL;