From owner-freebsd-questions@FreeBSD.ORG Wed May 23 08:22:57 2012 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id D2DA71065674; Wed, 23 May 2012 08:22:57 +0000 (UTC) (envelope-from venkatduvvuru.ml@gmail.com) Received: from mail-gg0-f182.google.com (mail-gg0-f182.google.com [209.85.161.182]) by mx1.freebsd.org (Postfix) with ESMTP id 4AF368FC0C; Wed, 23 May 2012 08:22:57 +0000 (UTC) Received: by ggnm2 with SMTP id m2so7748012ggn.13 for ; Wed, 23 May 2012 01:22:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=JRpQ4tiPVFqWeOICIwPxfMvKJYrxpgfMxUZQptDRW4k=; b=c1okEyAa3/2QCKMbTzfxFXXS4NTJb4QGQTIZJ1H6iGJGy4q0gFiBdBGCHbNJH+baXN ViCnC6roS1XRAYcTmhAJDaTExfulFbdVf4HVnVf+jaSFx4VWlSrvC7wxNpDiwkfCVYEg mAYTJCWMSXyAhkVfGB0JgOOp57YTlmZVBO0fLgyRzeDlQH6qUy9WtJLaHoKet5kqfmjX +GijvX5wlPWxAgJGyY5hvhsCNaodNH3ZjpjsAzsXEpnOhZThj4GRgH2GWq5xGwnZ1dJ0 UC0DHZSYDtjm8H8iusjpdTCVG0VV0WSpplXdnd6CieEVQLO/SmUJ7q0tJ5ZOSx2+UkZh O1Ag== MIME-Version: 1.0 Received: by 10.42.141.133 with SMTP id o5mr17014323icu.13.1337761375967; Wed, 23 May 2012 01:22:55 -0700 (PDT) Received: by 10.64.12.205 with HTTP; Wed, 23 May 2012 01:22:55 -0700 (PDT) In-Reply-To: References: <72B744D5-3D24-4A56-907C-2A8F6620877B@FreeBSD.org> Date: Wed, 23 May 2012 13:52:55 +0530 Message-ID: From: Venkat Duvvuru To: lstewart@freebsd.org Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: freebsd-net@freebsd.org, "Bjoern A. Zeeb" , freebsd-questions@freebsd.org, Jack Vogel Subject: Re: LRO support for IPv6 X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 23 May 2012 08:22:57 -0000 Folks, Can somebody please explain me why "tcp checsum" calculation is mandated in the freebsd network stack (tcp_input--->in6_cksum) albeit the card supports it? Probably Steve is the right person who can answer this. /Venkat On Wed, May 23, 2012 at 11:27 AM, Venkat Duvvuru wrote: > Ok. I found the reason for the throughput drop in case of IPv6. > Reason is that the "tcp check sum" calculation is mandated in case of IPv6 > irrespective of whether the card is doing it or not (checksum offload). Is > there a reason why freebsd is doing it that way? > > /Venkat > > On Tue, May 22, 2012 at 11:16 PM, Jack Vogel wrote: > >> LRO is a huge win for 10G (as is TSO on the TX side), so odds are good >> its behind the drop, >> in any case you'll be able to test that soon :) >> >> Jack >> >> >> >> On Tue, May 22, 2012 at 10:35 AM, Venkat Duvvuru < >> venkatduvvuru.ml@gmail.com> wrote: >> >>> Thanks for the response. >>> >>> I observed that there is a significant performance drop in case of IPv6 >>> on the "rx" side. >>> While I'm able to hit line rate ~9.5 Gbps on a 10gb NIC for IPv4..I >>> could only get ~6 Gbps on the "rx" front for IPv6...However "tx" for IPv6 >>> is on par with IPv4 hitting almost line rates. >>> >>> Could this be because of lack of LRO6?? >>> >>> Note: hwpmc profiling shows that most of the time is spent in the IPv6 >>> stack code >>> >>> /Venkat >>> On Tue, May 22, 2012 at 10:37 PM, Bjoern A. Zeeb wrote: >>> >>>> >>>> On 22. May 2012, at 17:04 , Jack Vogel wrote: >>>> >>>> > Oh, that's right, distracted with other projects and I forgot, now we >>>> just need >>>> > to have an LRO that works with forwarding eh :) >>>> >>>> That's a 6 line bainaid commit afterwards, basically returning form the >>>> LRO queuing >>>> function in case forwarding is turned on for that address family; a >>>> proper solution >>>> for long term can than be done whenever we feel like it. The above we >>>> should have done >>>> years ago;) >>>> >>>> >>>> > You ROCK bz :) >>>> > >>>> > Jack >>>> > >>>> > >>>> > On Tue, May 22, 2012 at 10:01 AM, Bjoern A. Zeeb >>>> wrote: >>>> > >>>> > On 22. May 2012, at 16:50 , Jack Vogel wrote: >>>> > >>>> > > The LRO code as it stands right now is IPV4 specific, it would be >>>> nice to >>>> > > extend it, one of >>>> > > many improvements that may get done at some point. >>>> > >>>> > I am about to commit it to HEAD. Bear another few days with me; I >>>> know >>>> > I am running late but committing new code had less prio than some >>>> other >>>> > real life things currently. >>>> > >>>> > I'll also bring TSO6, etc... >>>> >>>> -- >>>> Bjoern A. Zeeb You have to have visions! >>>> It does not matter how good you are. It matters what good you do! >>>> >>>> >>> >> >