From owner-freebsd-net@FreeBSD.ORG Mon Jul 7 22:13:03 2008 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id B59CA106567D for ; Mon, 7 Jul 2008 22:13:03 +0000 (UTC) (envelope-from peterjeremy@optushome.com.au) Received: from mail13.syd.optusnet.com.au (mail13.syd.optusnet.com.au [211.29.132.194]) by mx1.freebsd.org (Postfix) with ESMTP id 452B98FC13 for ; Mon, 7 Jul 2008 22:13:03 +0000 (UTC) (envelope-from peterjeremy@optushome.com.au) Received: from server.vk2pj.dyndns.org (c122-106-215-175.belrs3.nsw.optusnet.com.au [122.106.215.175]) by mail13.syd.optusnet.com.au (8.13.1/8.13.1) with ESMTP id m67MCwVJ016846 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 8 Jul 2008 08:12:59 +1000 Received: from server.vk2pj.dyndns.org (localhost.vk2pj.dyndns.org [127.0.0.1]) by server.vk2pj.dyndns.org (8.14.2/8.14.2) with ESMTP id m67MCwnH068137; Tue, 8 Jul 2008 08:12:58 +1000 (EST) (envelope-from peter@server.vk2pj.dyndns.org) Received: (from peter@localhost) by server.vk2pj.dyndns.org (8.14.2/8.14.2/Submit) id m67MCvGe068136; Tue, 8 Jul 2008 08:12:57 +1000 (EST) (envelope-from peter) Date: Tue, 8 Jul 2008 08:12:57 +1000 From: Peter Jeremy To: Julian Elischer Message-ID: <20080707221257.GH62764@server.vk2pj.dyndns.org> References: <2d3001c8def1$f4309b90$020b000a@bartwrkstxp> <486FFF70.3090402@gtcomm.net> <48701921.7090107@gtcomm.net> <4871E618.1080500@freebsd.org> <20080708002228.G680@besplex.bde.org> <48724238.2020103@freebsd.org> <20080708034304.R21502@delplex.bde.org> <20080708045135.V1022@besplex.bde.org> <48727BA9.6020702@elischer.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="hQiwHBbRI9kgIhsi" Content-Disposition: inline In-Reply-To: <48727BA9.6020702@elischer.org> X-PGP-Key: http://members.optusnet.com.au/peterjeremy/pubkey.asc User-Agent: Mutt/1.5.18 (2008-05-17) Cc: FreeBSD Net Subject: Re: Freebsd IP Forwarding performance (question, and some info) [7-stable, current, em, smp] X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 07 Jul 2008 22:13:03 -0000 --hQiwHBbRI9kgIhsi Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 2008-Jul-07 13:25:13 -0700, Julian Elischer wrote: >what you need is a speculative prefetch where you an tell teh=20 >processor "We will probably need the following address so start=20 >getting it while we go do other stuff". This looks like the PREFETCH instructions that exist in at least amd64 and SPARC. Unfortunately, their optimal use is very implementation- dependent and the AMD documentation suggests that incorrect use can degrade performance. --=20 Peter Jeremy Please excuse any delays as the result of my ISP's inability to implement an MTA that is either RFC2821-compliant or matches their claimed behaviour. --hQiwHBbRI9kgIhsi Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (FreeBSD) iEYEARECAAYFAkhylOkACgkQ/opHv/APuIf8cACgtZVatoLIA+W0RtB+atFbbhiy WBgAoMHGNn/i3Rs4y4wD7c9Odcfswne+ =MR/n -----END PGP SIGNATURE----- --hQiwHBbRI9kgIhsi--