From owner-freebsd-stable Wed Mar 5 0:27:42 2003 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 41A9D37B401 for ; Wed, 5 Mar 2003 00:27:41 -0800 (PST) Received: from salmon.maths.tcd.ie (salmon.maths.tcd.ie [134.226.81.11]) by mx1.FreeBSD.org (Postfix) with SMTP id 21B5743F75 for ; Wed, 5 Mar 2003 00:27:40 -0800 (PST) (envelope-from dwmalone@maths.tcd.ie) Received: from walton.maths.tcd.ie by salmon.maths.tcd.ie with SMTP id ; 5 Mar 2003 08:27:39 +0000 (GMT) Date: Wed, 5 Mar 2003 08:27:29 +0000 From: David Malone To: "Imtiaz, Fazle" Cc: freebsd-stable@freebsd.org Subject: Re: Hyper Threading Support in FreeBSD 4.7 Message-ID: <20030305082729.GA26393@walton.maths.tcd.ie> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.3i Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Tue, Mar 04, 2003 at 08:27:21PM -0600, Imtiaz, Fazle wrote: > I run a very high traffic web site with FreeBSD 4.7 and am considering > moving into Dual Xeon based platform. Does FreeBSD 4.7 support > hyper threading and if it does, are there any known issues and problems > with it? My system is already SMP enabled, does anything special need > to be done? 4.7 supports hyperthreading only if the BIOS includes the virtual CPUs in the MP table. Some BIOSes do this, and others do not. 4.8-PRERELEASE will always enable hyperthreading if the processors are capable of it. 4.8-RELEASE will probably make this a kernel option, so people who don't want hyperthreading can turn it off. John Balwdin is finalising the details of the option at the moment. David. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message