src/os_cpu/linux_ppc/vm/os_linux_ppc.cpp

rev 12305 : 8169373: Work around linux NPTL stack guard error.
Summary: Also streamline OS guard page handling on linuxs390, linuxppc, aixppc.

*** 545,555 ****
    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) {
!   return 2 * page_size();
  }
  
  // Java thread:
  //
  //   Low memory addresses
--- 545,557 ----
    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) {
!   // 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
*** 605,614 ****
--- 607,622 ----
  
      if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) {
        fatal("Can not locate current stack attributes!");
      }
  
+     // Work around NPTL stack guard error.
+     size_t guard_size = 0;
+     pthread_attr_getguardsize(&attr, &guard_size);
+     *bottom += guard_size;
+     *size   -= guard_size;
+     
      pthread_attr_destroy(&attr);
  
    }
    assert(os::current_stack_pointer() >= *bottom &&
           os::current_stack_pointer() < *bottom + *size, "just checking");