From owner-freebsd-smp Sun Feb 2 15:44:00 1997 Return-Path: Received: (from root@localhost) by freefall.freebsd.org (8.8.5/8.8.5) id PAA20973 for smp-outgoing; Sun, 2 Feb 1997 15:44:00 -0800 (PST) Received: from who.cdrom.com (who.cdrom.com [204.216.27.3]) by freefall.freebsd.org (8.8.5/8.8.5) with ESMTP id PAA20957 for ; Sun, 2 Feb 1997 15:43:53 -0800 (PST) Received: from snowcrash.cymru.net (snowcrash.cymru.net [163.164.160.3]) by who.cdrom.com (8.7.5/8.6.11) with ESMTP id PAA11541 for ; Sun, 2 Feb 1997 15:43:19 -0800 (PST) Received: (from alan@localhost) by snowcrash.cymru.net (8.7.1/8.7.1) id XAA01582; Sun, 2 Feb 1997 23:07:36 GMT From: Alan Cox Message-Id: <199702022307.XAA01582@snowcrash.cymru.net> Subject: Re: SMP To: terry@lambert.org (Terry Lambert) Date: Sun, 2 Feb 1997 23:07:34 +0000 (GMT) Cc: davem@jenolan.rutgers.edu, terry@lambert.org, michaelh@cet.co.jp, netdev@roxanne.nuclecu.unam.mx, roque@di.fc.ul.pt, freebsd-smp@freebsd.org, smpdev@roxanne.nuclecu.unam.mx In-Reply-To: <199702022135.OAA08696@phaeton.artisoft.com> from "Terry Lambert" at Feb 2, 97 02:35:27 pm Content-Type: text Sender: owner-smp@freebsd.org X-Loop: FreeBSD.org Precedence: bulk > Well, Sun generally does things right. I was more concerned with > a number of Intel motherboards where we are seeing APIC_IO problems. > They seem to fail this case. The intel boards get the hardware coherency right. After all its exactly the same for dual CPU as for CPU and PCI master. Certainly some single CPU boards get this wrong for specific cases. Just look at the matrox meteor list .. > I don't know what lists you follow, but just in the past two days, > the has been a person on the FreeBSD SMP list running a motherboard > with "improved cache handling" that seems to be barfing on something > like this when APIC_IO is used... 8-(. The APICs have a pile of little 'features'. Read the intel errata before playing. Also if you have B stepping Pentiums (except the MMX) you might as well stop on boot. Early on there were several Linux cases of 'weird crash' that came down to faulty boards/cache. Even some of them boards that worked fine single CPU. Alan