src/os_cpu/linux_s390/vm/os_linux_s390.cpp

rev 12283 : 8169373: Work around linux NPTL stack guard error.
Summary: Also streamline OS guard page handling on linuxs390, linuxppc, aixppc.

@@ -464,25 +464,27 @@
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // thread stack
 
+// These sizes exclude OS stack guard pages, but include
+// the VM guard pages.
 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
+// Return default stack size for thr_type.
 size_t os::Posix::default_stack_size(os::ThreadType thr_type) {
-  // default stack size (compiler thread needs larger stack)
+  // Default stack size (compiler thread needs larger stack).
   size_t s = (thr_type == os::compiler_thread ? 4 * M : 1024 * K);
   return s;
 }
 
 size_t os::Linux::default_guard_size(os::ThreadType thr_type) {
-  // z/Architecture: put 2 guard pages right in the middle of thread stack. This value
-  // should be consistent with the value used by register stack handling code.
-  return 2 * page_size();
+  // Creating guard page is very expensive. Java thread has HotSpot
+  // guard page, only enable glibc guard page for non-Java threads.
+  return (thr_type == java_thread ? 0 : page_size());
 }
 
 // Java thread:
 //
 //   Low memory addresses