From owner-freebsd-performance@FreeBSD.ORG Fri Dec 22 20:22:30 2006 Return-Path: X-Original-To: freebsd-performance@freebsd.org Delivered-To: freebsd-performance@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 29F2F16A40F; Fri, 22 Dec 2006 20:22:30 +0000 (UTC) (envelope-from alexander@leidinger.net) Received: from redbull.bpaserver.net (redbullneu.bpaserver.net [213.198.78.217]) by mx1.freebsd.org (Postfix) with ESMTP id CBCD213C49D; Fri, 22 Dec 2006 20:22:29 +0000 (UTC) (envelope-from alexander@leidinger.net) Received: from outgoing.leidinger.net (p54A5E998.dip.t-dialin.net [84.165.233.152]) by redbull.bpaserver.net (Postfix) with ESMTP id 3D65A2E192; Fri, 22 Dec 2006 20:30:45 +0100 (CET) Received: from Magellan.Leidinger.net (Magellan.Leidinger.net [192.168.1.1]) by outgoing.leidinger.net (Postfix) with ESMTP id 3B27C5B480D; Fri, 22 Dec 2006 20:29:34 +0100 (CET) Date: Fri, 22 Dec 2006 20:29:33 +0100 From: Alexander Leidinger To: Bruce Evans Message-ID: <20061222202933.709d2279@Magellan.Leidinger.net> In-Reply-To: <20061222222757.G18486@delplex.bde.org> References: <458B3651.8090601@paradise.net.nz> <458B3E0C.6090104@freebsd.org> <20061222222757.G18486@delplex.bde.org> X-Mailer: Claws Mail 2.6.1 (GTK+ 2.10.6; i386-portbld-freebsd7.0) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-BPAnet-MailScanner-Information: Please contact the ISP for more information X-BPAnet-MailScanner: Found to be clean X-BPAnet-MailScanner-SpamCheck: not spam, SpamAssassin (not cached, score=-14.787, required 6, autolearn=not spam, BAYES_00 -15.00, DK_POLICY_SIGNSOME 0.00, FORGED_RCVD_HELO 0.14, TW_CP 0.08) X-BPAnet-MailScanner-From: alexander@leidinger.net X-Spam-Status: No Cc: Adrian Chadd , rookie@gufi.org, freebsd-performance@FreeBSD.org, Mark Kirkwood , David Xu Subject: Re: Cached file read performance X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 22 Dec 2006 20:22:30 -0000 Quoting Bruce Evans (Fri, 22 Dec 2006 23:37:53 +1100 (EST)): > On Fri, 22 Dec 2006, Adrian Chadd wrote: > > > On 22/12/06, David Xu wrote: > > > >> I suspect in such a test, memory copying speed will be a key factor, > >> I don't have number to back up my idea, but I think Linux has lots > >> of tweaks, such as using MMX instruction to copy data. > > > > I had the oppertunity to study the AMD Athlon XP Optimisation guide > > and noted their example copy routine, optimised for the chipset, was > > quite a hell of a lot faster over a straight block copy. > > > > Has anyone here done any similar modifications to optimise > > copyin/copyout? I can't imagine it'd be a bad thing to have. > > Sure. It's a larger win mainly in benchmarks. It's a twisty MD maze. I want to point out http://www.freebsd.org/projects/ideas/#p-memcpy here. Just in case someone wants to play around a little bit. Bye, Alexander. -- I like your SNOOPY POSTER!! http://www.Leidinger.net Alexander @ Leidinger.net: PGP ID = B0063FE7 http://www.FreeBSD.org netchild @ FreeBSD.org : PGP ID = 72077137