From owner-freebsd-net@FreeBSD.ORG Sun Jun 3 23:20:58 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 58875106564A for ; Sun, 3 Jun 2012 23:20:58 +0000 (UTC) (envelope-from bounces+73574-866e-freebsd-net=freebsd.org@sendgrid.me) Received: from o3.shared.sendgrid.net (o3.shared.sendgrid.net [208.117.48.85]) by mx1.freebsd.org (Postfix) with SMTP id 0754C8FC08 for ; Sun, 3 Jun 2012 23:20:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sendgrid.info; h= message-id:date:from:mime-version:to:cc:subject:references :in-reply-to:content-type:content-transfer-encoding; s=smtpapi; bh=TP2YYjoqcZPHs/YQTtJTxgKF2/Y=; b=J9KkJeNrCD7HCIl1CMpo/XgzuA8C XSjV/LLPkHso4wR0fPi7EVFsGDww52giYTJx6FPIQui6G6zMjqe7/3XrVLBu6MuL 2377UMOUB1JhPircjwZ5OQgmlpRA2vVjiOL1ScvUkqA/PMLw3SLKn8OZIGoHUaFC RPKPIMYS3Ev9mWw= Received: by 10.41.149.113 with SMTP id f04-10.11496.4FCBF1593 Sun, 03 Jun 2012 23:20:57 +0000 (UTC) Received: from mail.tarsnap.com (unknown [10.9.180.5]) by mi3 (SG) with ESMTP id 4fcbf159.132c.447a819 for ; Sun, 03 Jun 2012 18:20:57 -0500 (CST) Received: (qmail 36134 invoked from network); 3 Jun 2012 23:13:15 -0000 Received: from unknown (HELO clamshell.daemonology.net) (127.0.0.1) by mail.tarsnap.com with ESMTP; 3 Jun 2012 23:13:15 -0000 Received: (qmail 36421 invoked from network); 3 Jun 2012 23:20:45 -0000 Received: from unknown (HELO clamshell.daemonology.net) (127.0.0.1) by clamshell.daemonology.net with SMTP; 3 Jun 2012 23:20:45 -0000 Message-ID: <4FCBF14D.4000103@freebsd.org> Date: Sun, 03 Jun 2012 16:20:45 -0700 From: Colin Percival User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:12.0) Gecko/20120509 Thunderbird/12.0.1 MIME-Version: 1.0 To: "Bjoern A. Zeeb" References: <4FC635CC.5030608@freebsd.org> <4FC63D27.70807@cs.duke.edu> <4FCB95F6.30204@freebsd.org> <2C0C246D-DFC1-45EE-88D9-C0730538F662@lists.zabbadoz.net> In-Reply-To: <2C0C246D-DFC1-45EE-88D9-C0730538F662@lists.zabbadoz.net> X-Enigmail-Version: 1.5pre Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Sendgrid-EID: ISGKkmHlRE12gnWy0TjFyGQSFR1WnpjQdICm3qu6YxEdfJT1DuC3EGxFeOe/vQrg6KslUf8M0zj6cwmIPkV4pNYUpxCWgP6+CbVpL33q5WIMeeuj9MqIjOLONCR8Q0btZ84jWQN2MYq6+E3+V2bJxSp+puHWFFBCkcxkCoDfQw8= Cc: freebsd-net@freebsd.org, Andrew Gallatin Subject: Re: [please review] TSO mbuf chain length limiting patch X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 03 Jun 2012 23:20:58 -0000 On 06/03/12 15:56, Bjoern A. Zeeb wrote: > On 3. Jun 2012, at 16:51 , Colin Percival wrote: >> I've attached a new patch which: >> 1. adds a IFCAP_TSO_MSS "capability" and a if_tx_tso_mss field to struct ifnet, >> 2. sets these in netfront when the IFCAP_TSO4 flag is set, >> 3. extends tcp_maxmtu to read this value, >> 4. adds a tx_tso_mss field to struct tcpcb, >> 5. makes tcp_mss_update set tx_tso_mss using tcp_maxmtu, and >> 6. limits TSO lengths to tx_tso_mss in tcp_output. > > general question - what happens in the IPv6 case? It should work just fine; when I said "tcp_maxmtu" I really meant "tcp_maxmtu and tcp_maxmtu6". Of course, this all only affects TSO, and the netfront driver doesn't enable TSO for IPv6 (yet), so in a sense the real answer is "nothing at all". But the infrastructure will be in place for when it's needed. -- Colin Percival Security Officer Emeritus, FreeBSD | The power to serve Founder, Tarsnap | www.tarsnap.com | Online backups for the truly paranoid