From owner-freebsd-stable@FreeBSD.ORG Mon Mar 15 12:58:32 2004 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3781A16A4CF for ; Mon, 15 Mar 2004 12:58:32 -0800 (PST) Received: from yertle.kcilink.com (yertle.kcilink.com [65.205.34.180]) by mx1.FreeBSD.org (Postfix) with ESMTP id B7D3643D45 for ; Mon, 15 Mar 2004 12:58:31 -0800 (PST) (envelope-from vivek@khera.org) Received: from [192.168.7.103] (host-103.int.kcilink.com [192.168.7.103]) by yertle.kcilink.com (Postfix) with ESMTP id D6D19217E9 for ; Mon, 15 Mar 2004 15:46:21 -0500 (EST) Mime-Version: 1.0 (Apple Message framework v612) In-Reply-To: <20040315152550.M213@Daath.hq.communityconnect.com> References: <20040315152550.M213@Daath.hq.communityconnect.com> Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: Content-Transfer-Encoding: 7bit From: Vivek Khera Date: Mon, 15 Mar 2004 15:46:22 -0500 To: freebsd-stable@freebsd.org X-Mailer: Apple Mail (2.612) Subject: Re: HyperThreading CPU's X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 15 Mar 2004 20:58:32 -0000 On Mar 15, 2004, at 3:38 PM, Marius M. Rex MARIUS wrote: > In my fairly recent version of the UPDATING file for 4.9-stable it > states > that I have to use sysctl to modify the value of > 'machdep.hlt_logical_cpus' to > '0' to get all of my logical CPU's enabled under hyperthreading. > > Is this change still necessary? sysctl spits that oid out as unknown > when I try to look at it. I do have similar oids but nothing that > matches that > value precisely: The OID only shows up if your CPU reports the "HTT" feature. Look at /var/run/dmesg.boot and look for the line "Features=" under the CPU information right near the top of the kernel boot messages. One of the features should be "HTT". If you disable hyperthreading in your bios, then it will not be there, and the OID will not be there either. later in the kernel boot messages it should show the APIC configuration/reprogramming and indicate multiple processors are present. I'm not sure if you need to enable multiple CPU support for HTT, since both of my HTT machines have two physical processors in them. I have never tried it on a single cpu box. =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Vivek Khera, Ph.D. Khera Communications, Inc. Internet: khera@kciLink.com Rockville, MD +1-301-869-4449 x806 AIM: vivekkhera Y!: vivek_khera http://www.khera.org/~vivek/