src/os_cpu/aix_ppc/vm/os_aix_ppc.cpp

rev 12363 : 8169373: Work around linux NPTL stack guard error.
Summary: Also skip libc guard page for compiler thread, merge similar code on linux platforms, and streamline libc guard page handling on linuxs390, linuxppc, aixppc.
Reviewed-by: dholmes, dcubed
rev 12364 : imported patch compilerGuardFix.patch

@@ -533,15 +533,15 @@
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // thread stack
 
-// These sizes exclude libc stack guard pages, but include
-// the HotSpot guard pages.
-size_t os::Posix::_compiler_thread_min_stack_allowed = 512 * K;
-size_t os::Posix::_java_thread_min_stack_allowed = 512 * K;
-size_t os::Posix::_vm_internal_thread_min_stack_allowed = 128 * K;
+// Minimum usable stack sizes required to get to user code. Space for
+// HotSpotguard pages is added later.
+size_t os::Posix::_compiler_thread_min_stack_allowed = 192 * K;
+size_t os::Posix::_java_thread_min_stack_allowed = 64 * K;
+size_t os::Posix::_vm_internal_thread_min_stack_allowed = 64 * K;
 
 // 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).
   size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);