From owner-freebsd-smp Mon Mar 10 10:44:42 2003 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 97F4337B404 for ; Mon, 10 Mar 2003 10:44:41 -0800 (PST) Received: from mail.speakeasy.net (mail17.speakeasy.net [216.254.0.217]) by mx1.FreeBSD.org (Postfix) with ESMTP id A388343F85 for ; Mon, 10 Mar 2003 10:44:40 -0800 (PST) (envelope-from jhb@FreeBSD.org) Received: (qmail 25638 invoked from network); 10 Mar 2003 18:44:46 -0000 Received: from unknown (HELO server.baldwin.cx) ([216.27.160.63]) (envelope-sender ) by mail17.speakeasy.net (qmail-ldap-1.03) with DES-CBC3-SHA encrypted SMTP for ; 10 Mar 2003 18:44:46 -0000 Received: from laptop.baldwin.cx (gw1.twc.weather.com [216.133.140.1]) by server.baldwin.cx (8.12.6/8.12.6) with ESMTP id h2AIf0hT065702; Mon, 10 Mar 2003 13:41:03 -0500 (EST) (envelope-from jhb@FreeBSD.org) Message-ID: X-Mailer: XFMail 1.5.2 on FreeBSD X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: <20030310182918.GA32085@murmeldjur.it.su.se> Date: Mon, 10 Mar 2003 13:44:51 -0500 (EST) From: John Baldwin To: Richard Nyberg Subject: Re: hyperthreading randomness Cc: freebsd-smp@FreeBSD.org Sender: owner-freebsd-smp@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org On 10-Mar-2003 Richard Nyberg wrote: > On Mon, Mar 10, 2003 at 01:00:13PM -0500, John Baldwin wrote: >> >> On 08-Mar-2003 Richard Nyberg wrote: >> > I have a Dell Precision 450 with 2 xeon CPU:s. >> > The weird thing is that it randomly boots up >> > with either 2 or 4 CPUs on the same 4-STABLE kernel. >> > 2 more often than 4. It seems a bit unpredictable :( >> >> Hmm, I have no idea about that one. Hmm, it seems to be a >> "feature" of the BIOS perhaps. It seems that it may be listing >> the second CPU with an APIC ID of 3 (it's second core) instead >> of 2 (it's first core) in which case the HTT code sees that >> something is not right and doesn't start up any extra processors. >> > > I see. > > Do you think this quirk will cause trouble when FreeBSD gets its > CPU info from ACPI? No. With ACPI the BIOS tells us all the CPUs and we don't have to guess at the existence of any CPUs. -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message