From owner-freebsd-smp@FreeBSD.ORG  Mon Jul 14 13:06:30 2003
Return-Path: <owner-freebsd-smp@FreeBSD.ORG>
Delivered-To: freebsd-smp@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id AF36037B401
	for <freebsd-smp@freebsd.org>; Mon, 14 Jul 2003 13:06:29 -0700 (PDT)
Received: from ztxmail03.ztx.compaq.com (ztxmail03.ztx.compaq.com
	[161.114.1.207])
	by mx1.FreeBSD.org (Postfix) with ESMTP id E855943F75
	for <freebsd-smp@freebsd.org>; Mon, 14 Jul 2003 13:06:28 -0700 (PDT)
	(envelope-from john.cagle@hp.com)
Received: from cceexg11.americas.cpqcorp.net (cceexg11.americas.cpqcorp.net
	[16.110.250.125])	by ztxmail03.ztx.compaq.com (Postfix) with ESMTP
	id 82419A2A3; Mon, 14 Jul 2003 15:06:28 -0500 (CDT)
Received: from cceexc19.americas.cpqcorp.net ([16.110.250.85]) by
	cceexg11.americas.cpqcorp.net with Microsoft SMTPSVC(5.0.2195.6673);
	Mon, 14 Jul 2003 15:06:28 -0500
X-MimeOLE: Produced By Microsoft Exchange V6.0.6375.0
content-class: urn:content-classes:message
MIME-Version: 1.0
Content-Type: text/plain;
	charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
Date: Mon, 14 Jul 2003 15:05:48 -0500
Message-ID: <C50AB9511EE59B49B2A503CB7AE1ABD10476C7AF@cceexc19.americas.cpqcorp.net>
X-MS-Has-Attach: 
X-MS-TNEF-Correlator: 
Thread-Topic: maximum of CPUs
Thread-Index: AcNKQqDRGkdZ1euPRnS2DgHd/+8aXQAAFqJg
From: "Cagle, John (ISS-Houston)" <john.cagle@hp.com>
To: "Attila Nagy" <bra@fsn.hu>
X-OriginalArrivalTime: 14 Jul 2003 20:06:28.0398 (UTC)
	FILETIME=[6927B4E0:01C34A43]
cc: freebsd-smp@freebsd.org
cc: =?iso-8859-1?Q?Patrik_Vesel=EDk?= <veselik@ssakhk.cz>
Subject: RE: maximum of CPUs
X-BeenThere: freebsd-smp@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: FreeBSD SMP implementation group <freebsd-smp.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-smp>,
	<mailto:freebsd-smp-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-smp>
List-Post: <mailto:freebsd-smp@freebsd.org>
List-Help: <mailto:freebsd-smp-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-smp>,
	<mailto:freebsd-smp-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 14 Jul 2003 20:06:30 -0000

If you enable hyperthreading on an 8-way server, you'll end up with 16 =
logical processors (and a *whole bunch* of APIC's) -- a scenario that is =
not comprehended by FreeBSD.  In other words, there needs to be some =
more engineering done on FreeBSD to support more than 8 processors =
(AFAICT).

> -----Original Message-----
> From: Attila Nagy [mailto:bra@fsn.hu]=20
> Sent: Monday, July 14, 2003 2:59 PM
> To: Cagle, John (ISS-Houston)
> Cc: Patrik Vesel=EDk; freebsd-smp@freebsd.org
> Subject: Re: maximum of CPUs
>=20
>=20
> Cagle, John (ISS-Houston) wrote:
> > I think that 8 CPUs is pretty much the limit for FreeBSD.
>  > We have FreeBSD 5.1 running on an 8-way HP ProLiant DL740 and HP
>  > ProLiant DL760.  (That's 8 processors *without* using=20
> hyperthreading.)
> Just out of curiosity: what happens if you enable hyperthreading?