From owner-freebsd-net@freebsd.org Fri May 27 07:38:08 2016 Return-Path: Delivered-To: freebsd-net@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 4DC16B4C10E for ; Fri, 27 May 2016 07:38:08 +0000 (UTC) (envelope-from kmacybsd@gmail.com) Received: from mail-it0-x22e.google.com (mail-it0-x22e.google.com [IPv6:2607:f8b0:4001:c0b::22e]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 174D11A0C; Fri, 27 May 2016 07:38:08 +0000 (UTC) (envelope-from kmacybsd@gmail.com) Received: by mail-it0-x22e.google.com with SMTP id l63so68277665ita.1; Fri, 27 May 2016 00:38:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to; bh=8Kz9Nb6VsMB7Y0Rjaj3CT6aY6JGNP6Tx6pGaNJcGGgE=; b=LfbIG8oy3B05ISGkQgoqd4PWJq1wtTYL/YVgGWN4KqqpUp3WI4WHiWoc4N45LtKRAf U9h/i+gDd+v4V8AmXQ/fyYFLE8oJqGHgg/+S3q/oCXNPCPAPq2VifQZfYpTcvwGWE3/f N7yQ8BnlqvRRB2dpXc5Tgu2dwcjaHYZzqcEKy6SkohVhMl2YDRwFOhX6xViWNZVPfUvt /HU18NikU86GSldfgK5K40/OJJOPACc6BmWZWNWTnBLim9JjDdqPnazNIWh6r6fK+uP+ 7GH9i6dy4/4KtSpzU1tuRNjaH5oWuXQxxmhfdoH8gqz3L2Mz793G4/Nc96WaEEQf/xCq SVRQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:sender:in-reply-to:references:date :message-id:subject:from:to; bh=8Kz9Nb6VsMB7Y0Rjaj3CT6aY6JGNP6Tx6pGaNJcGGgE=; b=mli4sft8fNI4OVpc+61DLOOzMubuqwMIl3ExdzoX0wg3Yx0HCEApN3RYLJuLNI/7sl JRqWEmjoUnuojSMcztc5mR2rxrDj5b5wsytlBTmmXmb+UDU8sp7iqsLAt0MLVNC0q5mF mxRIlGplQJmZEu+WVQNh86KXM5rgI6n5wd7Zs7dfHqUOE/T5l6VSkJQnqt7HiMUIGnez 7f1/wfWQRaN0/JSPwDlYDbPqjQuUZDLamNbo+P5FY5rdzO/cmV4ou+aNngpKQHOBu/KS MQ3NuITsKKd7tvIQrLiF+LPRLSl/+mHxpIhEAW5yjPs08qS+Ot9lL7RSkZL+yUU7S4mS eQUw== X-Gm-Message-State: ALyK8tIGdthrEjIMugR/r9Iwx/pRkOkIGaI6OKG88F5ncUT0Os1vo9v87TWIQLDL2eFvtgdu1yn4IywHYnFbRQ== MIME-Version: 1.0 X-Received: by 10.36.29.13 with SMTP id 13mr6475022itj.99.1464334687513; Fri, 27 May 2016 00:38:07 -0700 (PDT) Sender: kmacybsd@gmail.com Received: by 10.107.132.212 with HTTP; Fri, 27 May 2016 00:38:07 -0700 (PDT) In-Reply-To: <20160527072951.GC10148@ox> References: <201605270457.u4R4vYqu018911@hergotha.csail.mit.edu> <20160527063731.GB10148@ox> <20160527072951.GC10148@ox> Date: Fri, 27 May 2016 00:38:07 -0700 X-Google-Sender-Auth: KbuuQhfph4buc54EaZ3FD4S4S-U Message-ID: Subject: Re: Changing MTU on cxgbe From: "K. Macy" To: "K. Macy" , Garrett Wollman , "dmarquess@gmail.com" , "freebsd-net@freebsd.org" Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.22 X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 27 May 2016 07:38:08 -0000 On Friday, May 27, 2016, Navdeep Parhar wrote: > On Fri, May 27, 2016 at 12:23:02AM -0700, K. Macy wrote: > > On Thursday, May 26, 2016, Navdeep Parhar > wrote: > > > > > On Fri, May 27, 2016 at 12:57:34AM -0400, Garrett Wollman wrote: > > > > In article < > > > CAJpsHY4vF5Ky6GuAusLOOROgiQuyD2CcRmVxu8x3cArQRZxcbg@mail.gmail.com > > > > > you write: > > > > > > > > ># ifconfig -m cxgbe0 > > > > >cxgbe0: flags=8943 > > > > > > > > ># ifconfig cxgbe0 mtu 9000 > > > > >ifconfig: ioctl SIOCSIFMTU (set mtu): Invalid argument > > > > > > > > I believe this device, like many others, does not allow the MTU (or > > > > actually the MRU) to be changed once the receive ring has been set up > > > > > > This is not correct. You can change the MTU of a cxgbe/cxl interface > at > > > any time (whether it's up or down, passing traffic or idle, etc.). > > > > > > For some reason the stack needs init to be called when the MTU is changed > > for it to actually change the size of the packets passed to the driver. > At > > least cxgb does not do that. I'm not at my computer right now, but cxgbe > > may be the same. If that's the case just up / down the interface. It > _will_ > > take effect without that if it's passed at module load. Sorry. Continue on. -M > > The problem that was reported was that the ioctl that sets the MTU > failed, not that the ioctl succeeded but the MTU change did not take > effect. > Regards, > Navdeep >