From owner-freebsd-hackers  Mon May 19 22:56:17 1997
Return-Path: <owner-hackers>
Received: (from root@localhost)
          by hub.freebsd.org (8.8.5/8.8.5) id WAA14919
          for hackers-outgoing; Mon, 19 May 1997 22:56:17 -0700 (PDT)
Received: from godzilla.zeta.org.au (godzilla.zeta.org.au [203.2.228.19])
          by hub.freebsd.org (8.8.5/8.8.5) with ESMTP id WAA14914;
          Mon, 19 May 1997 22:56:14 -0700 (PDT)
Received: (from bde@localhost) by godzilla.zeta.org.au (8.8.5/8.6.9) id PAA19649; Tue, 20 May 1997 15:55:00 +1000
Date: Tue, 20 May 1997 15:55:00 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199705200555.PAA19649@godzilla.zeta.org.au>
To: dg@root.com, peter@spinner.DIALix.COM
Subject: Re: trap type 29 on P6
Cc: freebsd-bugs@FreeBSD.ORG, freebsd-hackers@FreeBSD.ORG,
        thorpej@nas.nasa.gov, yokota@zodiac.mech.utsunomiya-u.ac.jp
Sender: owner-hackers@FreeBSD.ORG
X-Loop: FreeBSD.org
Precedence: bulk

>Hmm.. But what I want to know is why the local APIC is doing this when 
>it's not active?  And why does it coincide with IO instructions?
>
>Anyway, assuming that's the case, how does this look:
>Index: trap.c

I don't like ignoring unexpected exceptions.  I would only ignore
exception 15 on P6's (it's sort of expected there).

The nearby (old) NMI/POWERFAIL ifdefs and code is disgusting and
broken (the NMI gate should be an interrupt gate and interrupts should
be kept masked until the NMI handler returns).

Bruce