From owner-freebsd-questions@FreeBSD.ORG Wed Jan 12 17:41:05 2005 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id D8BE016A4CE for ; Wed, 12 Jan 2005 17:41:05 +0000 (GMT) Received: from smtp9.wanadoo.fr (smtp9.wanadoo.fr [193.252.22.22]) by mx1.FreeBSD.org (Postfix) with ESMTP id 3936F43D45 for ; Wed, 12 Jan 2005 17:41:05 +0000 (GMT) (envelope-from atkielski.anthony@wanadoo.fr) Received: from me-wanadoo.net (localhost [127.0.0.1]) by mwinf0907.wanadoo.fr (SMTP Server) with ESMTP id A936A1C00157 for ; Wed, 12 Jan 2005 18:41:03 +0100 (CET) Received: from pix.atkielski.com (ASt-Lambert-111-2-1-3.w81-50.abo.wanadoo.fr [81.50.80.3]) by mwinf0907.wanadoo.fr (SMTP Server) with ESMTP id 663F11C00151 for ; Wed, 12 Jan 2005 18:41:03 +0100 (CET) Date: Wed, 12 Jan 2005 18:41:02 +0100 From: Anthony Atkielski X-Priority: 3 (Normal) Message-ID: <1869737534.20050112184102@wanadoo.fr> To: freebsd-questions@freebsd.org In-Reply-To: <20050112111542.GA1651@orion.daedalusnetworks.priv> References: <9094-SnapperMsgD246FC56BE0A255B@68.243.126.247> <20050112014359.GA3722@gothmog.gr> <35de0c30050111210235ea3060@mail.gmail.com> <20050112052901.GA61033@osiris.chen.org.nz> <167683180.20050112072014@wanadoo.fr> <20050112111542.GA1651@orion.daedalusnetworks.priv> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Subject: Re: Hyperthreading hurts 5.3? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: freebsd-questions@freebsd.org List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 12 Jan 2005 17:41:06 -0000 Giorgos Keramidas writes: GK> You need to enable SMP too, to allow the FreeBSD kernel to use the GK> second (hyper-threaded) CPU. I found it, in a file called SMP. Why is the SMP option tucked away in a separate file? I stuck this into the config and rebuilt the kernel. Seems to run fine. I see that top has a C column now, and running a program in a continuous loop takes up exactly 50% of the machine (and two such programs take up exactly 100%), according to top. Boot messages looked a bit different: The Regents of the University of California. All rights reserved. FreeBSD 5.3-RELEASE #0: Wed Jan 12 17:55:18 CET 2005 root@freebie.atkielski.com:/usr/obj/usr/src/sys/FREEBIE-SMP Timecounter "i8254" frequency 1193182 Hz quality 0 CPU: Intel(R) Pentium(R) 4 CPU 3.00GHz (2998.57-MHz 686-class CPU) Origin = "GenuineIntel" Id = 0xf34 Stepping = 4 Features=0xbfebfbff Hyperthreading: 2 logical CPUs real memory = 1073414144 (1023 MB) avail memory = 1045061632 (996 MB) ACPI APIC Table: FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs cpu0 (BSP): APIC ID: 0 cpu1 (AP): APIC ID: 1 [...] cpu0: on acpi0 cpu1: on acpi0 [...] SMP: AP CPU #1 Launched! So I guess it's all working now. That was easy. I imagine this will give me a bit more horsepower for the buck, although--with only 0.2% of the machine busy under normal load even with a single processor--I guess I wasn't exactly processor-bound to begin with (I'd run out of I/O capacity long before running out of processor). But why not profit from what's there, eh? -- Anthony