From owner-freebsd-net@FreeBSD.ORG Thu Nov 8 23:33:00 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 11028EF7; Thu, 8 Nov 2012 23:33:00 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: from mail-pb0-f54.google.com (mail-pb0-f54.google.com [209.85.160.54]) by mx1.freebsd.org (Postfix) with ESMTP id C51BC8FC12; Thu, 8 Nov 2012 23:32:59 +0000 (UTC) Received: by mail-pb0-f54.google.com with SMTP id wz17so791012pbc.13 for ; Thu, 08 Nov 2012 15:32:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; bh=EdAfVcmobIuGRHeDqQbtGSRe1a1SHLbU8snzTpLwqMQ=; b=hpTFQyHSY29vT6NR2Ui+FzHprrVgn6EXzn1FtdhqUF3TtuU3/DHt1UaJv4zyCEuNaO hwFU4e5p2iCtmfnxeTw93Vwk/OIaV2/DLt4fpV87kQbPBf1GQc7DlOBLB530NzSV2jua KYFQMzqEeAbxVKKn1dTTfJPBpPI23o0DFFYJHpxfAVnfq+xKsfPodGsco/qDN0xeFRiO Y0EnVIHfrhBFzTB+ItjP7rvy+KmkKwrIiNBJZtg1B1SD7B5RPcbEE5ttGM4dK4xOo/Rf ZOMB/lyjnBuAptsAVCO09gzdxt2/xpVvC2QXtBlCrrtJizMO4+yn7UTeAN61S2GPeZJG Rihw== MIME-Version: 1.0 Received: by 10.68.209.166 with SMTP id mn6mr376748pbc.95.1352417579609; Thu, 08 Nov 2012 15:32:59 -0800 (PST) Sender: adrian.chadd@gmail.com Received: by 10.68.124.130 with HTTP; Thu, 8 Nov 2012 15:32:59 -0800 (PST) In-Reply-To: <509BC2E2.4030907@freebsd.org> References: <201211080206.qA826RiN054539@svn.freebsd.org> <20121108023858.GA3127@michelle.cdnetworks.com> <509BC2E2.4030907@freebsd.org> Date: Thu, 8 Nov 2012 15:32:59 -0800 X-Google-Sender-Auth: DHIUUH5FPDDmDKcoGoowNfKBwSY Message-ID: Subject: Re: svn commit: r242739 - stable/9/sys/dev/ti From: Adrian Chadd To: Andre Oppermann Content-Type: text/plain; charset=ISO-8859-1 Cc: pyunyh@gmail.com, FreeBSD Net , Pyun YongHyeon 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: Thu, 08 Nov 2012 23:33:00 -0000 On 8 November 2012 06:34, Andre Oppermann wrote: > TCP/UDP doesn't (want to) generate any fragments at all and tries > to avoid it at almost all cost. We want to send very large packets > and have the NIC fragment/segment it (TSO/UDP frag offload). What about if it's a router and the frames don't have DF set? Not that it should happen often, however.. > >> We could create a device or interface flag that indicates whether the >> driver can handle multiple mbufs chained via m_nextpkt through >> if_transmit(), and then teach one or two drivers that particular >> logic. > > > Agreed. I think that's the way to go. It must be very well specified > in semantics though. Otherwise it's just too easy to leak mbuf all > over the place. I mentioned this to Robert Watson today at the FreeBSD vendor summit and he said much the same thing about testing and assertions. Adrian