--- old/hotspot/src/os_cpu/aix_ppc/vm/os_aix_ppc.cpp	Fri Sep  9 10:41:45 2016
+++ new/hotspot/src/os_cpu/aix_ppc/vm/os_aix_ppc.cpp	Fri Sep  9 10:41:44 2016
@@ -533,23 +533,17 @@
 ////////////////////////////////////////////////////////////////////////////////
 // thread stack
 
-size_t os::Aix::min_stack_allowed = 128*K;
+size_t os::Posix::_compiler_thread_min_stack_allowed = 128 * K;
+size_t os::Posix::_java_thread_min_stack_allowed = 128 * K;
+size_t os::Posix::_vm_internal_thread_min_stack_allowed = 128 * K;
 
 // return default stack size for thr_type
-size_t os::Aix::default_stack_size(os::ThreadType thr_type) {
+size_t os::Posix::default_stack_size(os::ThreadType thr_type) {
   // default stack size (compiler thread needs larger stack)
-  // Notice that the setting for compiler threads here have no impact
-  // because of the strange 'fallback logic' in os::create_thread().
-  // Better set CompilerThreadStackSize in globals_<os_cpu>.hpp if you want to
-  // specify a different stack size for compiler threads!
   size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
   return s;
 }
 
-size_t os::Aix::default_guard_size(os::ThreadType thr_type) {
-  return 2 * page_size();
-}
-
 /////////////////////////////////////////////////////////////////////////////
 // helper functions for fatal error handler