From owner-freebsd-net@FreeBSD.ORG  Tue Jun 10 08:25:42 2008
Return-Path: <owner-freebsd-net@FreeBSD.ORG>
Delivered-To: freebsd-net@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id A68C5106567D
	for <freebsd-net@freebsd.org>; Tue, 10 Jun 2008 08:25:42 +0000 (UTC)
	(envelope-from yonyossef.lists@gmail.com)
Received: from yw-out-2324.google.com (yw-out-2324.google.com [74.125.46.31])
	by mx1.freebsd.org (Postfix) with ESMTP id 643D68FC12
	for <freebsd-net@freebsd.org>; Tue, 10 Jun 2008 08:25:42 +0000 (UTC)
	(envelope-from yonyossef.lists@gmail.com)
Received: by yw-out-2324.google.com with SMTP id 9so1259384ywe.13
	for <freebsd-net@freebsd.org>; Tue, 10 Jun 2008 01:25:39 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma;
	h=domainkey-signature:received:received:message-id:date:from:to
	:subject:mime-version:content-type;
	bh=xj0exH8xC8wMn6t4c1nsq8Ik7J2Q5kUcsICoqyu84XQ=;
	b=rXLbcE5CFKCqATQJmbL/9dqKTMWoJ0msVzfscxLkVgTmjc3gAYBnvcm+et87KH2slh
	CRImytHzJzNtK+9aQWwJDVfoo9bUZNF2L454tEfG5itxW3QW1sh7pLlpd69ZpCmUWzM+
	off4qwlBt+XciRCG8eaHPrnbjvqrTb9FMNyDo=
DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma;
	h=message-id:date:from:to:subject:mime-version:content-type;
	b=pE5w4wADtLm7Nvccrl5Z2pwRUNW2562C15d075pVjgMox+038uLK8oovHEHkTItSnA
	U+YlNfGswHGJWtHeVf/REkH4SyWX7CBQ/CnWnBw2pfeweWXi2F3xHpk9iz6QtYdF1KFc
	Ks2rrD/DLREXuHwfQXNNYFD+TnPHbhx2nmANM=
Received: by 10.151.84.12 with SMTP id m12mr8031981ybl.2.1213086339574;
	Tue, 10 Jun 2008 01:25:39 -0700 (PDT)
Received: by 10.151.84.2 with HTTP; Tue, 10 Jun 2008 01:25:39 -0700 (PDT)
Message-ID: <20def4870806100125l7b5b1e6fhd295d46d1106abb5@mail.gmail.com>
Date: Tue, 10 Jun 2008 11:25:39 +0300
From: "Yony Yossef" <yonyossef.lists@gmail.com>
To: freebsd-net@freebsd.org
MIME-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
X-Content-Filtered-By: Mailman/MimeDel 2.1.5
Subject: tso_segsz and mss above jumbo MTU in FreeBSD 7
X-BeenThere: freebsd-net@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Networking and TCP/IP with FreeBSD <freebsd-net.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/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: Tue, 10 Jun 2008 08:25:42 -0000

Hi All.

I'm working on a 10GigE driver for FreeBSD 7.

Looking at other GigE and 10GigE drivers I've seen that
mbuf->m_pkthdr.tso_segsz is assigned to MSS (Max Segment Size) on the Tx
routines.
If I understand correctly the tso_segsz is supposed to inform the driver
with the MTU set by the OS, therefore it should change upon ifconfig mtu
commands.
When I set my MTU to 9600 I still recieve tso_segsz=1500 in the Tx mbufs
from the OS.

Where's my mistake here?

Yony