From owner-freebsd-smp Mon Mar 3 15: 5:42 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 091AA37B509 for ; Mon, 3 Mar 2003 15:05:41 -0800 (PST) Received: from mail.speakeasy.net (mail13.speakeasy.net [216.254.0.213]) by mx1.FreeBSD.org (Postfix) with ESMTP id BC05E43F75 for ; Mon, 3 Mar 2003 15:05:39 -0800 (PST) (envelope-from jhb@FreeBSD.org) Received: (qmail 5682 invoked from network); 3 Mar 2003 23:05:47 -0000 Received: from unknown (HELO server.baldwin.cx) ([216.27.160.63]) (envelope-sender ) by mail13.speakeasy.net (qmail-ldap-1.03) with DES-CBC3-SHA encrypted SMTP for ; 3 Mar 2003 23:05:47 -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 h23N3IhT042723; Mon, 3 Mar 2003 18:03:18 -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: Date: Mon, 03 Mar 2003 18:05:53 -0500 (EST) From: John Baldwin To: Julian Elischer Subject: RE: UP ans SMP on the same kernel Cc: 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 03-Mar-2003 Julian Elischer wrote: > > > How much work would it take to make a kernel that could run > on both SMP and UP machines (and use the extra CPUs?) > > UP kernels can run on SMP hardware, so I guess that it's mainly finding > a way of switching from using the PIC to using some APICS > dynamically, when you find that you have SMP hardware. > > Incidently I have several UP machines that have APICs > and it may be effective to be able to run an APIC > kernel on this hardware.. > > (This all assumes that the rest of the kernel was compiled > SMP to have all the lockeng etc.) I am working on this, but it's taking a while amongst other distractions. The real work is in the PIC vs. APIC stuff. The actual SMP part is fairly easy as the sparc64, alpha, and ia64 ports demonstrate. -- 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