From owner-freebsd-net@FreeBSD.ORG Mon Dec 31 23:04:54 2012 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id DF9B9445 for ; Mon, 31 Dec 2012 23:04:54 +0000 (UTC) (envelope-from barney_cordoba@yahoo.com) Received: from nm4-vm1.bullet.mail.ne1.yahoo.com (nm4-vm1.bullet.mail.ne1.yahoo.com [98.138.91.44]) by mx1.freebsd.org (Postfix) with ESMTP id 8C6D88FC0A for ; Mon, 31 Dec 2012 23:04:54 +0000 (UTC) Received: from [98.138.226.179] by nm4.bullet.mail.ne1.yahoo.com with NNFMP; 31 Dec 2012 23:04:48 -0000 Received: from [98.138.88.238] by tm14.bullet.mail.ne1.yahoo.com with NNFMP; 31 Dec 2012 23:04:48 -0000 Received: from [127.0.0.1] by omp1038.mail.ne1.yahoo.com with NNFMP; 31 Dec 2012 23:04:48 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 13307.66571.bm@omp1038.mail.ne1.yahoo.com Received: (qmail 67935 invoked by uid 60001); 31 Dec 2012 23:04:47 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s1024; t=1356995087; bh=MYJsEihiSmKFh+LxwSFQ5Moml0I7VkO4IXGpvJqPplg=; h=X-YMail-OSG:Received:X-Rocket-MIMEInfo:X-Mailer:Message-ID:Date:From:Subject:To:Cc:In-Reply-To:MIME-Version:Content-Type; b=Z/9GScnFGNhotBsa2gLH72RLXBi9UaWhHIzzZ3ya1zjngVbeTmBl6G22FzPXyBF2mhxk+ZFomnkLk0lRNPLRcukkTIMnpp+QRfeWVqZOhaB+vxQ9L/0WS9g2TbdC+Pnoe8sfI8thQ+gz4irwO9TaY814/TA9lzO6yULf2H+SXJU= DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Rocket-MIMEInfo:X-Mailer:Message-ID:Date:From:Subject:To:Cc:In-Reply-To:MIME-Version:Content-Type; b=yFX6Vv1eO/aA6OJMmVaP08wcYs/PxHWeQ/xthZjGChVrB4glGgz+e+UF5k1wFQyMm2ssbJmKTj7+l8O+M0tCzCRU2Z+tcPok766WxbN5JPKfIlevgXbWyxZWpJklRnwBvWC2VqEMiioMeBkLAPyJWw5VRNGzC9y53yb1qdPbKEo=; X-YMail-OSG: axTbSQAVM1n30k.8PLv8u0EMyeZfaHnRdP.g4B6.re9LDYx w3ynkYhpt0OVKkC8o2Yj4sgmqBO0urqPgIKDvnwEmxnIFORp4rr7ue5es3L. L0srbOva6c1d1chpnjCfDKIl5L5BJK8F1mCnSCj5016FWdZx8.tfeuRqJAWA caTpyw_IwGK9LCFqXcTcHmoJFsDMJT1eWVQpgazJxzmDKA8P7K2S98G.cj4p 6u.hXhs72phEmPDwvTrYr6sZ6NT9YXwFXMu7uqFEN4SjScKPVG7UG5DlivoO SD6voScvkpoW9AMmyR92D7lNHhgw8ZJamTZg3Bmo.sRxuarzqW5zv9Mk_9v5 5aNPa4jXZtoirS1sb5RdWcMI7kzCgLAB4HMKVkMv9bdKGFhrQyiGuslJI8nw ZhsenLhQCXNOs_p7HBs.CuBunFSlc7oSgkIJOAC57_lKanDMNGKtnC0Pn9nM UWhiwTxKqBSGfna3pbSkgsJSGxAYqLQNsS4XHwD0J8q0GVl6s3ELuZ9JvuS6 HNnY7fiBQYxefvJUh4PYcL0M9Bfj0JA-- Received: from [174.48.128.27] by web121604.mail.ne1.yahoo.com via HTTP; Mon, 31 Dec 2012 15:04:47 PST X-Rocket-MIMEInfo: 001.001, CgotLS0gT24gTW9uLCAxMi8zMS8xMiwgQWRyaWFuIENoYWRkIDxhZHJpYW5AZnJlZWJzZC5vcmc.IHdyb3RlOgoKPiBGcm9tOiBBZHJpYW4gQ2hhZGQgPGFkcmlhbkBmcmVlYnNkLm9yZz4KPiBTdWJqZWN0OiBSZToga2Vybi8xNzQ4NTE6IFtieGVdIFtwYXRjaF0gVURQIGNoZWNrc3VtIG9mZmxvYWQgaXMgd3JvbmcgaW4gYnhlIGRyaXZlcgo.IFRvOiAiR2FycmV0dCBDb29wZXIiIDx5YW5lZ29taUBnbWFpbC5jb20.Cj4gQ2M6ICJCYXJuZXkgQ29yZG9iYSIgPGJhcm5leV9jb3Jkb2JhQHlhaG9vLmNvbT4sICIBMAEBAQE- X-Mailer: YahooMailClassic/15.1.2 YahooMailWebService/0.8.129.483 Message-ID: <1356995087.59212.YahooMailClassic@web121604.mail.ne1.yahoo.com> Date: Mon, 31 Dec 2012 15:04:47 -0800 (PST) From: Barney Cordoba Subject: Re: kern/174851: [bxe] [patch] UDP checksum offload is wrong in bxe driver To: Garrett Cooper , Adrian Chadd In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: freebsd-net@freebsd.org, David Christensen , linimon@freebsd.org X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.14 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, 31 Dec 2012 23:04:54 -0000 --- On Mon, 12/31/12, Adrian Chadd wrote: > From: Adrian Chadd > Subject: Re: kern/174851: [bxe] [patch] UDP checksum offload is wrong in bxe driver > To: "Garrett Cooper" > Cc: "Barney Cordoba" , "David Christensen" , linimon@freebsd.org, freebsd-net@freebsd.org > Date: Monday, December 31, 2012, 2:00 PM > On 31 December 2012 07:58, Garrett > Cooper > wrote: > > > I would ask David about whether or not there was a > performance > > difference because they might have some numbers for > if_bxe. > > > > Not sure about the concept in general, but it seems > like a reasonable > > application protocol specific request. But by and > large, I agree that > > UDP checksumming doesn't make logical sense because it > adds > > unnecessary overhead on a L3 protocol that's assumed to > be unreliable. > > People are terminating millions of VoIP calls on FreeBSD > devices. All using UDP. > > I can imagine large scale VoIP gateways wanting to try and > benefit from this. > The statement above "assumes" that there is a benefit. voIP packets are short, so the benefit of offloading is reduced. There is some delay added by the hardware, and there are cpu cycles used in managing the offload code. So those operations not only muddy the code, but they may not be faster than simply doing the checksum on a much, much faster cpu. BC