you have to enable it with a boot time parameter. Prior to 2.4.2-ac18
the NMI-oopser is enabled unconditionally on x86 SMP boxes.
+On x86-64 the NMI oopser is on by default. On 64bit Intel CPUs
+it uses IO-APIC by default and on AMD it uses local APIC.
+
[ feel free to send bug reports, suggestions and patches to
Ingo Molnar <mingo@redhat.com> or the Linux SMP mailing
list at <linux-smp@vger.kernel.org> ]