From owner-freebsd-smp Thu Sep 12 11:41:01 1996 Return-Path: owner-smp Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id LAA22036 for smp-outgoing; Thu, 12 Sep 1996 11:41:01 -0700 (PDT) Received: from phaeton.artisoft.com (phaeton.Artisoft.COM [198.17.250.211]) by freefall.freebsd.org (8.7.5/8.7.3) with SMTP id LAA22028 for ; Thu, 12 Sep 1996 11:40:59 -0700 (PDT) Received: (from terry@localhost) by phaeton.artisoft.com (8.6.11/8.6.9) id LAA07343; Thu, 12 Sep 1996 11:38:32 -0700 From: Terry Lambert Message-Id: <199609121838.LAA07343@phaeton.artisoft.com> Subject: Re: Intel XXpress - some SMP benchmarks To: smp@csn.net (Steve Passe) Date: Thu, 12 Sep 1996 11:38:32 -0700 (MST) Cc: terry@lambert.org, peter@spinner.dialix.com, rv@groa.uct.ac.za, freebsd-smp@FreeBSD.org In-Reply-To: <199609121823.MAA18695@clem.systemsix.com> from "Steve Passe" at Sep 12, 96 12:23:59 pm X-Mailer: ELM [version 2.4 PL24] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-smp@FreeBSD.org X-Loop: FreeBSD.org Precedence: bulk > >> One thing I'm not clear about from the IO apic docs yet is whether there > >> are 15 cpu's and 15 IO apic's, or whether there's a limit of 15 devices on > >> the APIC bus. > > > > 1 BP, 31 (AP | IO APIC) (2^5 == 32) > > its a four bit register, where do you get 2^5, am I missing something? Oh, ugh. Sequent supports 32 processors. I wonder how? Corrected value: 1 BP, 15 (AP | IO APIC) (2^4 == 16) > > You may want to disassemble your MP cold boot BIOS code to see about > > I've been wondering about the issue of the MP table being in BIOS. > Traditionally this is ROM. Do you think they just hardcode all this > stuff, or really arbitrate numbers during boot and can 'modify' them in the > BIOS area because it is really shadowed into RAM? Some of the stuff has to be arbitrary... the cache writeback/writethrough is enough to make me believe that. It changes with CMOS settings. Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.