From owner-freebsd-stable@FreeBSD.ORG Wed May 3 15:36:55 2006 Return-Path: X-Original-To: freebsd-stable@freebsd.org 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 71E9F16A401 for ; Wed, 3 May 2006 15:36:55 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from pi.codefab.com (pi.codefab.com [199.103.21.227]) by mx1.FreeBSD.org (Postfix) with ESMTP id 13A1543D46 for ; Wed, 3 May 2006 15:36:55 +0000 (GMT) (envelope-from cswiger@mac.com) Received: from localhost (localhost [127.0.0.1]) by pi.codefab.com (Postfix) with ESMTP id 61FD75DA6; Wed, 3 May 2006 11:36:54 -0400 (EDT) X-Virus-Scanned: amavisd-new at codefab.com Received: from pi.codefab.com ([127.0.0.1]) by localhost (pi.codefab.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id nXpOnVcU99Hm; Wed, 3 May 2006 11:36:53 -0400 (EDT) Received: from [192.168.1.251] (pool-68-160-235-217.ny325.east.verizon.net [68.160.235.217]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by pi.codefab.com (Postfix) with ESMTP id 167495C82; Wed, 3 May 2006 11:36:53 -0400 (EDT) Message-ID: <4458CE13.6060804@mac.com> Date: Wed, 03 May 2006 11:36:51 -0400 From: Chuck Swiger User-Agent: Thunderbird 1.5.0.2 (Windows/20060308) MIME-Version: 1.0 To: "Marc G. Fournier" References: <20060503113955.U1147@ganymede.hub.org> In-Reply-To: <20060503113955.U1147@ganymede.hub.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-stable@freebsd.org Subject: Re: Hyperthreading in 6.x ... still frowned upon? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 03 May 2006 15:36:55 -0000 Marc G. Fournier wrote: > In 4.x, it was a 'shut it off' sort of deal .. my new amd64 don't > appear to have it enabled, but my older i386 server that I just > upgraded to 6.x does: > > user pid %cpu %mem vsz rss tt state start time command > root 14 104.0 0.0 0 8 ?? RL 11:38AM 0:55.02 > [idle: cpu0] > root 11 99.1 0.0 0 8 ?? RL 11:38AM 0:00.00 [idle: > cpu3] > root 13 99.1 0.0 0 8 ?? RL 11:38AM 0:00.00 [idle: > cpu1] > root 12 98.0 0.0 0 8 ?? RL 11:38AM 0:54.54 [idle: > cpu2] > > Is it still something that I should disable, and, if so, how in 6.x? You should test it for the workloads you have, but most of the time, HT isn't especially helpful. AMD64 CPUs come in dual-core format rather than HT-enabled. If you've seen "HT" or "HTT" applied to an AMD system, it's likely an abbreviation for "HyperTransport" or "HyperTransport Technology". -- -Chuck