From owner-freebsd-net@FreeBSD.ORG  Wed Aug 14 19:47:10 2013
Return-Path: <owner-freebsd-net@FreeBSD.ORG>
Delivered-To: net@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by hub.freebsd.org (Postfix) with ESMTP id 859A9EDE;
 Wed, 14 Aug 2013 19:47:10 +0000 (UTC)
 (envelope-from julian@freebsd.org)
Received: from vps1.elischer.org (vps1.elischer.org [204.109.63.16])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (No client certificate requested)
 by mx1.freebsd.org (Postfix) with ESMTPS id 57C5D221B;
 Wed, 14 Aug 2013 19:47:10 +0000 (UTC)
Received: from jre-mbp.elischer.org (etroy.elischer.org [121.45.226.51])
 (authenticated bits=0)
 by vps1.elischer.org (8.14.7/8.14.6) with ESMTP id r7EJl0JM019119
 (version=TLSv1/SSLv3 cipher=DHE-RSA-CAMELLIA256-SHA bits=256 verify=NO);
 Wed, 14 Aug 2013 12:47:02 -0700 (PDT)
 (envelope-from julian@freebsd.org)
Message-ID: <520BDEAE.9000104@freebsd.org>
Date: Thu, 15 Aug 2013 03:46:54 +0800
From: Julian Elischer <julian@freebsd.org>
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8;
 rv:17.0) Gecko/20130801 Thunderbird/17.0.8
MIME-Version: 1.0
To: Lawrence Stewart <lstewart@freebsd.org>
Subject: Re: TSO and FreeBSD vs Linux
References: <520A6D07.5080106@freebsd.org> <520AFBE8.1090109@freebsd.org>
 <520B24A0.4000706@freebsd.org> <520B3056.1000804@freebsd.org>
In-Reply-To: <520B3056.1000804@freebsd.org>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Cc: FreeBSD Net <net@freebsd.org>
X-BeenThere: freebsd-net@freebsd.org
X-Mailman-Version: 2.1.14
Precedence: list
List-Id: Networking and TCP/IP with FreeBSD <freebsd-net.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-net>,
 <mailto:freebsd-net-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-net>
List-Post: <mailto:freebsd-net@freebsd.org>
List-Help: <mailto:freebsd-net-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-net>,
 <mailto:freebsd-net-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 14 Aug 2013 19:47:10 -0000

On 8/14/13 3:23 PM, Lawrence Stewart wrote:
> On 08/14/13 16:33, Julian Elischer wrote:
>
>>> They switched to using an initial window of 10 segments some time ago.
>>> FreeBSD starts with 3 or more recently, 10 if you're running recent
>>> 9-STABLE or 10-CURRENT.
>> I tried setting initial values as shown:
>>    net.inet.tcp.local_slowstart_flightsize: 10
>>    net.inet.tcp.slowstart_flightsize: 10
>> it didn't seem to make too much difference but I will redo the test.
> Assuming this is still FreeBSD 8.0 as you mentioned out-of-band,
> changing those variables without disabling rfc3390 will have no effect.
>
> I think (check the driver code in question as I'm not sure) that if you
> "ifconfig <if> lro" and the driver has hardware support or has been made
> aware of our software implementation, it should DTRT.

so I ran on 9.2-beta ( a week or two old) and it had similar problems..
only worse.. 9.2 actually sends multiple packets when is doesn't need to..
     http://people.freebsd.org/~julian/fbsd9.png

>
> Cheers,
> Lawrence
>
>