From owner-freebsd-net@FreeBSD.ORG Wed Jul 4 19:59:39 2012 Return-Path: Delivered-To: net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 185D71065670; Wed, 4 Jul 2012 19:59:39 +0000 (UTC) (envelope-from melifaro@FreeBSD.org) Received: from mail.ipfw.ru (unknown [IPv6:2a01:4f8:120:6141::2]) by mx1.freebsd.org (Postfix) with ESMTP id 9CA058FC08; Wed, 4 Jul 2012 19:59:38 +0000 (UTC) Received: from v6.mpls.in ([2a02:978:2::5] helo=ws.su29.net) by mail.ipfw.ru with esmtpsa (TLSv1:CAMELLIA256-SHA:256) (Exim 4.76 (FreeBSD)) (envelope-from ) id 1SmVmK-000BuC-96; Thu, 05 Jul 2012 00:02:24 +0400 Message-ID: <4FF4A0A7.9050601@FreeBSD.org> Date: Wed, 04 Jul 2012 23:59:35 +0400 From: "Alexander V. Chernikov" User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:9.0) Gecko/20120121 Thunderbird/9.0 MIME-Version: 1.0 To: lev@FreeBSD.org References: <4FF319A2.6070905@FreeBSD.org> <4FF361CA.4000506@FreeBSD.org> <20120703214419.GC92445@onelab2.iet.unipi.it> <4FF36438.2030902@FreeBSD.org> <4FF3E2C4.7050701@FreeBSD.org> <4FF3FB14.8020006@FreeBSD.org> <4FF402D1.4000505@FreeBSD.org> <17110267579.20120704233705@serebryakov.spb.ru> In-Reply-To: <17110267579.20120704233705@serebryakov.spb.ru> Content-Type: text/plain; charset=windows-1251; format=flowed Content-Transfer-Encoding: 8bit Cc: Doug Barton , net@freebsd.org Subject: Re: FreeBSD 10G forwarding performance @Intel 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: Wed, 04 Jul 2012 19:59:39 -0000 On 04.07.2012 23:37, Lev Serebryakov wrote: > Hello, Alexander. > You wrote 4 èþëÿ 2012 ã., 12:46:09: > > > AVC> http://shader.kaist.edu/packetshader/ (and links there) are good example > AVC> of what is going on. > But HOW?! GPU has very high "preparation" and data transfer cost, > how it could be used for such small packets of data, as 1.5-9K > datagrams?! According to http://www.ndsl.kaist.edu/~kyoungsoo/papers/packetshader.pdf - cumulative dispatch latency is between 3.8-4.1 microseconds (section 2.2). And GPU is doing routing lookup only (at least for IPv4/IPv6 forwarding), so we're always transferring/receving fixed amount of data. Btw, there are exact hardware specifications in this document. >