diff -r df4fadccc378 -r 4f0c435f8c3c hotspot/src/share/vm/runtime/thread.cpp
--- a/hotspot/src/share/vm/runtime/thread.cpp	Thu Mar 11 14:41:29 2010 -0500
+++ b/hotspot/src/share/vm/runtime/thread.cpp	Fri Mar 12 10:42:16 2010 -0500
@@ -2137,7 +2137,7 @@
   int allocate = os::allocate_stack_guard_pages();
   // warning("Guarding at " PTR_FORMAT " for len " SIZE_FORMAT "\n", low_addr, len);
 
-  if (allocate && !os::commit_memory((char *) low_addr, len)) {
+  if (allocate && !os::create_stack_guard_pages((char *) low_addr, len)) {
     warning("Attempt to allocate stack guard pages failed.");
     return;
   }
@@ -2158,7 +2158,7 @@
   size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
 
   if (os::allocate_stack_guard_pages()) {
-    if (os::uncommit_memory((char *) low_addr, len)) {
+    if (os::remove_stack_guard_pages((char *) low_addr, len)) {
       _stack_guard_state = stack_guard_unused;
     } else {
       warning("Attempt to deallocate stack guard pages failed.");