From owner-freebsd-hackers@FreeBSD.ORG Mon Dec 27 19:56:36 2004 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 2296216A520 for ; Mon, 27 Dec 2004 19:56:35 +0000 (GMT) Received: from mail2.speakeasy.net (mail2.speakeasy.net [216.254.0.202]) by mx1.FreeBSD.org (Postfix) with ESMTP id E428A43D48 for ; Mon, 27 Dec 2004 19:56:34 +0000 (GMT) (envelope-from jhb@FreeBSD.org) Received: (qmail 18147 invoked from network); 27 Dec 2004 19:56:34 -0000 Received: from dsl027-160-063.atl1.dsl.speakeasy.net (HELO server.baldwin.cx) ([216.27.160.63]) (envelope-sender ) encrypted SMTP for ; 27 Dec 2004 19:56:34 -0000 Received: from [10.50.41.243] (gw1.twc.weather.com [216.133.140.1]) (authenticated bits=0) by server.baldwin.cx (8.12.11/8.12.11) with ESMTP id iBRJuJcW088548; Mon, 27 Dec 2004 14:56:27 -0500 (EST) (envelope-from jhb@FreeBSD.org) From: John Baldwin To: freebsd-hackers@FreeBSD.org Date: Mon, 27 Dec 2004 14:52:40 -0500 User-Agent: KMail/1.6.2 References: <36627.194.210.13.66.1102679886.squirrel@194.210.13.66> <20041210204824.GA53907@xor.obsecurity.org> In-Reply-To: <20041210204824.GA53907@xor.obsecurity.org> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200412271452.40348.jhb@FreeBSD.org> X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on server.baldwin.cx cc: klr@6s-gaming.com cc: Kris Kennaway Subject: Re: HTT/SMP servers instability on 5.3-STABLE X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 27 Dec 2004 19:56:38 -0000 On Friday 10 December 2004 03:48 pm, Kris Kennaway wrote: > On Fri, Dec 10, 2004 at 05:58:06AM -0600, klr@6s-gaming.com wrote: > > I've heard it can penalize performance because the scheduler isn't > > optimized for logical CPUs. Does having HTT enabled impacts the > > stability of the system? > > No. Actually, for 5.3 it does. HEAD has the problem fixed, not sure about RELENG_5 yet, but due to the way IPIs are done in 5.3, having more than 2 CPUs can be very destabilizing, so disabling HTT on a 2-way system so that it goes from 4 CPUs to 2 CPUs can help stability very much. -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org