From owner-freebsd-stable@FreeBSD.ORG Fri Oct 12 10:21:30 2007 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 52BAF16A417 for ; Fri, 12 Oct 2007 10:21:30 +0000 (UTC) (envelope-from jdc@parodius.com) Received: from mx01.sc1.parodius.com (mx01.sc1.parodius.com [72.20.106.3]) by mx1.freebsd.org (Postfix) with ESMTP id 34E3D13C458 for ; Fri, 12 Oct 2007 10:21:30 +0000 (UTC) (envelope-from jdc@parodius.com) Received: by mx01.sc1.parodius.com (Postfix, from userid 1000) id 287511CC037; Fri, 12 Oct 2007 03:21:30 -0700 (PDT) Date: Fri, 12 Oct 2007 03:21:30 -0700 From: Jeremy Chadwick To: Artem Kuchin Message-ID: <20071012102130.GA93158@eos.sc1.parodius.com> Mail-Followup-To: Artem Kuchin , freebsd-stable@freebsd.org References: <024901c80cb6$f49696b0$0c00a8c0@Artem> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <024901c80cb6$f49696b0$0c00a8c0@Artem> User-Agent: Mutt/1.5.16 (2007-06-09) Cc: freebsd-stable@freebsd.org Subject: Re: how to compiel kernel and world to maxium optimization 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: Fri, 12 Oct 2007 10:21:30 -0000 On Fri, Oct 12, 2007 at 02:02:09PM +0400, Artem Kuchin wrote: > The point is that if i have Xeon HT cpus (not very new, but > definitelly not Pentium PRO :) i can build kernel and world > using insttructions for this CPU and optimization for it, so > i would get myself a speedy system and less memory hungry, right? Not necessarily. This assumption is often driven by what I like to call the "Gentoo mentality". Throwing on optimisations and assuming the system will "magically be more efficient" is not how you gain efficiency; I grow tired of seeing programs mindlessly set -O3 and other insanities, based purely on assumptions. > The only option known to me which is related to the isee is cpu > setting in kernel config file. Anything else? By using CPUTYPE in /etc/make.conf. /usr/share/examples/etc/make.conf lists value values. For a Xeon, you should probably use "nocona", assuming the Xeon model you have supports SSE3 instructions. Other- wise, use "prescott". Also, very important: use CPUTYPE?=value and not CPUTYPE=value. There's a thread on the values (focusing around amd64, but the same applies to i386) below; see the post from Mike Meyer. http://groups.google.com/group/lucky.freebsd.amd64/browse_thread/thread/79b9b9664cc87ae5/6eb86b7ede208173?lnk=st&q=freebsd+cputype+xeon#6eb86b7ede208173 -- | Jeremy Chadwick jdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |