From owner-freebsd-stable Thu Feb 13 11:26:38 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 84F8137B401 for ; Thu, 13 Feb 2003 11:26:37 -0800 (PST) Received: from spork.pantherdragon.org (spork.pantherdragon.org [206.29.168.146]) by mx1.FreeBSD.org (Postfix) with ESMTP id 8C1E743FBF for ; Thu, 13 Feb 2003 11:26:36 -0800 (PST) (envelope-from dmp@pantherdragon.org) Received: from sparx.techno.pagans (12-224-208-117.client.attbi.com [12.224.208.117]) by spork.pantherdragon.org (Postfix) with ESMTP id D04C01005F; Thu, 13 Feb 2003 11:26:33 -0800 (PST) Received: from pantherdragon.org (speck.techno.pagans [172.21.42.2]) by sparx.techno.pagans (Postfix) with ESMTP id 98BE2AB6A; Thu, 13 Feb 2003 11:26:32 -0800 (PST) Message-ID: <3E4BF169.7010402@pantherdragon.org> Date: Thu, 13 Feb 2003 11:26:33 -0800 From: Darren Pilgrim User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.2.1) Gecko/20030210 X-Accept-Language: en-us, en MIME-Version: 1.0 To: =?ISO-8859-1?Q?=22Roub=EDcek_Zdenek_=28PragoNet=29=22?= Cc: stable@FreeBSD.ORG Subject: Re: 4.7-stable & smp References: <9256D57F598E6C41B288AA7DB94F29C9604A2A@pgnmail1.pgnaplikace.cz> In-Reply-To: <9256D57F598E6C41B288AA7DB94F29C9604A2A@pgnmail1.pgnaplikace.cz> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit 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 Roubícek Zdenek (PragoNet) wrote: > > Any chance to disable it (hyperthreading)? I just want 2 physical CPUs not 4 virtual working. JOOC, why don't you want it enabled? My understanding of the concept is HT allows the CPU to more fully utilize the available host bus bandwidth since a single, deep pipline won't normally make full use of a 200MHz host bus. Assuming the SMP code in FreeBSD is effective, I'd think you seriously cut into the CPU's performance by disabling HT. >From: Erik Trulsson [mailto:ertr1013@student.uu.se] >> >>On Wed, Feb 12, 2003 at 03:43:53PM -0800, Mike Hoskins wrote: >> >>>I don't recall seeing mention of "CPU #3" before. (It is a 2 CPU box.) >>>Is this actually something broken (seems to work just fine), or just >>>semantics? :) It does say "2 logical CPUs": >> >>It is not a bug, it is a feature. :-) >>The magical word here is "Hyperthreading". With Intel's latest P4 and >>Xeon CPUs you can treat each physical CPU as two logical CPUs. >>Basic support for this was recently added to -stable. You are seeing >>the results of this. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message