From owner-freebsd-net@FreeBSD.ORG Sat Jan 5 15:17:18 2013 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id 09E73A0 for ; Sat, 5 Jan 2013 15:17:18 +0000 (UTC) (envelope-from barney_cordoba@yahoo.com) Received: from nm13-vm1.bullet.mail.ne1.yahoo.com (nm13-vm1.bullet.mail.ne1.yahoo.com [98.138.91.62]) by mx1.freebsd.org (Postfix) with ESMTP id B3B43132 for ; Sat, 5 Jan 2013 15:17:17 +0000 (UTC) Received: from [98.138.90.53] by nm13.bullet.mail.ne1.yahoo.com with NNFMP; 05 Jan 2013 15:17:11 -0000 Received: from [98.138.89.171] by tm6.bullet.mail.ne1.yahoo.com with NNFMP; 05 Jan 2013 15:17:11 -0000 Received: from [127.0.0.1] by omp1027.mail.ne1.yahoo.com with NNFMP; 05 Jan 2013 15:17:10 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 994806.88279.bm@omp1027.mail.ne1.yahoo.com Received: (qmail 17569 invoked by uid 60001); 5 Jan 2013 15:17:10 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s1024; t=1357399030; bh=7mYSPBZoYdieWyEQ011sw0NRhi6z1gf9No2NXLisiaY=; 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=pBb1mIdNHhbDy7zWPpC28sEicjDTYk/K3UKdhvdoJuzUvFr2UejM+beO+akWFlklctYn2xUOQEMKLXcy1CLO+C7DAVyzSDY36ty9LEVFP3LWHzxRAO56RYXdmxYU0n/1BvfcZTMK5R+im6pzPEEF9IYSE8qXMVtHIs8EYElxSfM= 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=tUQPzEKtOC1KF+3v4gvgLLNf40tb2CSAYVeUjD5JcFIV1Pmb9xl8Q0KPDdzMHwz4Sjx8pDHrs8X6peOFWDoz0InGSwI/a880AJZvkTXmYKF59NwgypqmXS5KACDrVwtbeviq91OzYamqA5ZrSetROJpvJtOWyvO6fLd60zCq9rc=; X-YMail-OSG: XMtunNoVM1l8TCF96Js_IYI.zVilmll4O1JY3y1xT.D.km7 N.919JH.tiSGbuF2WDJ2nPke0etAJR00208l0a8pamNaPSXos3_1oAJOw2go .b.7C6VeCD2PHG1hyqXu8pPvhi7YsfE95r5SC5XQarQndaTckcIX2azZD_TU X6nT4IjsgLRtORioK77gQz8qrk61rcxMMDnj1dVYM4F6trdAnvHP_EgAFI7b sbiG5WzbpZJVkFoXWwmEhDJ6Smqtdsf.YnQ1FTw.Gk35IYd6wgKCLTk1v4Vi gDVrmYaPSgJnM1gG11YjTzkvvYyNf8OyiSsJ6keLcNxtjZgcogdTyn7ZhVhO 8IggATiUlApDEbKDADN3c5CdLgNxElYafuC19WuOR9s_6B8cryYUakAUbgAZ X7YMA3OdlG7VMPwN1osgH600xXd8VUtbtMtiwl_sNzTj6pGn5.8kZ_UMYgqz YeoZBFqGZXI0hWaDteqatyGlUTDVgxeQrAA_LWw4rW7PXEuPMxhjrCB3mA1m F8cDTsPUqLhHYN6v.YrHSVKn_rUcqsg-- Received: from [174.48.128.27] by web121603.mail.ne1.yahoo.com via HTTP; Sat, 05 Jan 2013 07:17:10 PST X-Rocket-MIMEInfo: 001.001, CgotLS0gT24gRnJpLCAxLzQvMTMsIFdpbGxlbSBKYW4gV2l0aGFnZW4gPHdqd0BkaWdpd2FyZS5ubD4gd3JvdGU6Cgo.IEZyb206IFdpbGxlbSBKYW4gV2l0aGFnZW4gPHdqd0BkaWdpd2FyZS5ubD4KPiBTdWJqZWN0OiBSZToga2Vybi8xNzQ4NTE6IFtieGVdIFtwYXRjaF0gVURQIGNoZWNrc3VtIG9mZmxvYWQgaXMgd3JvbmcgaW4gYnhlIGRyaXZlcgo.IFRvOiAiQmFybmV5IENvcmRvYmEiIDxiYXJuZXlfY29yZG9iYUB5YWhvby5jb20.Cj4gQ2M6ICJHYXJyZXR0IENvb3BlciIgPHlhbmVnb21pQGdtYWlsLmMBMAEBAQE- X-Mailer: YahooMailClassic/15.1.2 YahooMailWebService/0.8.129.483 Message-ID: <1357399030.5935.YahooMailClassic@web121603.mail.ne1.yahoo.com> Date: Sat, 5 Jan 2013 07:17:10 -0800 (PST) From: Barney Cordoba Subject: Re: kern/174851: [bxe] [patch] UDP checksum offload is wrong in bxe driver To: Willem Jan Withagen In-Reply-To: <50E6EA0C.5080005@digiware.nl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Garrett Cooper , freebsd-net@freebsd.org, Adrian Chadd , 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: Sat, 05 Jan 2013 15:17:18 -0000 --- On Fri, 1/4/13, Willem Jan Withagen wrote: > From: Willem Jan Withagen > Subject: Re: kern/174851: [bxe] [patch] UDP checksum offload is wrong in bxe driver > To: "Barney Cordoba" > Cc: "Garrett Cooper" , freebsd-net@freebsd.org, "Adrian Chadd" , "David Christensen" , linimon@freebsd.org > Date: Friday, January 4, 2013, 9:41 AM > On 2013-01-01 0:04, Barney Cordoba > wrote: > > > 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. > > Forgoing all the discussions on performance and possible > penalties in > drivers..... > > I think there is a large set of UDP streams (and growing) > that do use > larger packets. > > The video streaming we did used a size of header(14)+7*188, > which is the > max number of MPEG packet to fit into anything with an MTU > < 1500. > > Receiving those on small embedded devices which can do HW > check-summing > is very beneficial there. > On the large servers we would generate up to 5Gbit of > outgoing streams. > I'm sure that offloading UDP checks would be an advantage as > well. > (They did run mainly Linux, but FreeBSD would also work) > > Unfortunately most of the infrastructure has been taken > down, so it is > no longer possible to verify any of the assumptions. > > --WjW If you haven't benchmarked it, then you're just guessing. That's my point. Its like SMP in freeBSD 4. People bought big, honking machines and the big expensive machines were slower than a single core system at less than half the price. Just because something sounds better doesn't mean that it is better. BC