diff -r c7987cbaf2ca -r da4be62fb889 src/os_cpu/linux_x86/vm/os_linux_x86.cpp
--- a/src/os_cpu/linux_x86/vm/os_linux_x86.cpp	Fri Feb 24 12:33:31 2012 -0800
+++ b/src/os_cpu/linux_x86/vm/os_linux_x86.cpp	Mon Feb 27 09:17:44 2012 +0100
@@ -862,3 +862,11 @@
                       : "r" (fpu_cntrl) : "memory");
 #endif // !AMD64
 }
+
+#ifndef PRODUCT
+void os::verify_stack_alignment() {
+#ifdef AMD64
+  assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
+#endif
+}
+#endif