--- old/hotspot/src/os/aix/vm/os_aix.cpp	Wed Sep  7 16:14:53 2016
+++ new/hotspot/src/os/aix/vm/os_aix.cpp	Wed Sep  7 16:14:52 2016
@@ -847,7 +847,8 @@
   return 0;
 }
 
-bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) {
+bool os::create_thread(Thread* thread, ThreadType thr_type,
+                       size_t req_stack_size) {
 
   assert(thread->osthread() == NULL, "caller responsible");
 
@@ -880,37 +881,12 @@
   guarantee(pthread_attr_setsuspendstate_np(&attr, PTHREAD_CREATE_SUSPENDED_NP) == 0, "???");
 
   // calculate stack size if it's not specified by caller
-  if (stack_size == 0) {
-    stack_size = os::Aix::default_stack_size(thr_type);
-
-    switch (thr_type) {
-    case os::java_thread:
-      // Java threads use ThreadStackSize whose default value can be changed with the flag -Xss.
-      assert(JavaThread::stack_size_at_create() > 0, "this should be set");
-      stack_size = JavaThread::stack_size_at_create();
-      break;
-    case os::compiler_thread:
-      if (CompilerThreadStackSize > 0) {
-        stack_size = (size_t)(CompilerThreadStackSize * K);
-        break;
-      } // else fall through:
-        // use VMThreadStackSize if CompilerThreadStackSize is not defined
-    case os::vm_thread:
-    case os::pgc_thread:
-    case os::cgc_thread:
-    case os::watcher_thread:
-      if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
-      break;
-    }
-  }
-
-  stack_size = MAX2(stack_size, os::Aix::min_stack_allowed);
+  size_t stack_size = os::Posix::get_initial_stack_size(thr_type, req_stack_size);
   pthread_attr_setstacksize(&attr, stack_size);
 
   pthread_t tid;
   int ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread);
 
-
   char buf[64];
   if (ret == 0) {
     log_info(os, thread)("Thread started (pthread id: " UINTX_FORMAT ", attributes: %s). ",
@@ -3593,32 +3569,11 @@
   Aix::signal_sets_init();
   Aix::install_signal_handlers();
 
-  // Check minimum allowable stack size for thread creation and to initialize
-  // the java system classes, including StackOverflowError - depends on page
-  // size. Add two 4K pages for compiler2 recursion in main thread.
-  // Add in 4*BytesPerWord 4K pages to account for VM stack during
-  // class initialization depending on 32 or 64 bit VM.
-  os::Aix::min_stack_allowed = MAX2(os::Aix::min_stack_allowed,
-                                    JavaThread::stack_guard_zone_size() +
-                                    JavaThread::stack_shadow_zone_size() +
-                                    (4*BytesPerWord COMPILER2_PRESENT(+2)) * 4 * K);
-
-  os::Aix::min_stack_allowed = align_size_up(os::Aix::min_stack_allowed, os::vm_page_size());
-
-  size_t threadStackSizeInBytes = ThreadStackSize * K;
-  if (threadStackSizeInBytes != 0 &&
-      threadStackSizeInBytes < os::Aix::min_stack_allowed) {
-    tty->print_cr("\nThe stack size specified is too small, "
-                  "Specify at least %dk",
-                  os::Aix::min_stack_allowed / K);
+  // Check and sets minimum stack sizes against command line options
+  if (Posix::set_minimum_stack_sizes() == JNI_ERR) {
     return JNI_ERR;
   }
 
-  // Make the stack size a multiple of the page size so that
-  // the yellow/red zones can be guarded.
-  // Note that this can be 0, if no default stacksize was set.
-  JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes, vm_page_size()));
-
   if (UseNUMA) {
     UseNUMA = false;
     warning("NUMA optimizations are not available on this OS.");