From owner-freebsd-bugs@FreeBSD.ORG Fri Jan 13 18:23:21 2012 Return-Path: Delivered-To: freebsd-bugs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id D404A1065679 for ; Fri, 13 Jan 2012 18:23:21 +0000 (UTC) (envelope-from jfvogel@gmail.com) Received: from mail-we0-f182.google.com (mail-we0-f182.google.com [74.125.82.182]) by mx1.freebsd.org (Postfix) with ESMTP id 5E84A8FC16 for ; Fri, 13 Jan 2012 18:23:21 +0000 (UTC) Received: by werm12 with SMTP id m12so899977wer.13 for ; Fri, 13 Jan 2012 10:23:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=1sgfsOOX6I/4eaJwOY95VUexLE5MC5WpIqYSgXABN8w=; b=v3JuTdDveBa+ajUfhOwagbpsPhCAIPLvXvGS5l/YTIds0Jz1uTOprSapUewOyEZWf+ MkWnGf5DwUrgD63dD/k+vW5yxtvVlXBlpc67tdB1TyMpfJ+eF9j/J4p0VXQXC7M2wQ0C r6Itt7NGOaT8Prmda2FKuirqN5f4cdliTbSZo= MIME-Version: 1.0 Received: by 10.216.131.76 with SMTP id l54mr962869wei.34.1326477538254; Fri, 13 Jan 2012 09:58:58 -0800 (PST) Received: by 10.180.84.66 with HTTP; Fri, 13 Jan 2012 09:58:58 -0800 (PST) In-Reply-To: <4F106861.80507@cdf.toronto.edu> References: <4F106861.80507@cdf.toronto.edu> Date: Fri, 13 Jan 2012 09:58:58 -0800 Message-ID: From: Jack Vogel To: Iordan Iordanov Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: freebsd-bugs@freebsd.org, CDF Admin Subject: Re: unable to set mtu 9000 on Intel x520-t2 adapter X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 13 Jan 2012 18:23:21 -0000 Its a system resource thing, when you increase to a 9K mtu the driver will use 9K mbuf clusters, and with the queues and rings you have its unable to get enough. Very important to look at kern.ipc.nbm* In your case nmbjumbo9 is the pool, if you had 4K it would those clusters. Change the defaults in /etc/sysctl.conf. Cheers, Jack On Fri, Jan 13, 2012 at 9:22 AM, Iordan Iordanov wrote: > Hello, > > We are testing FreeBSD 9.0-RELEASE on a pair of machines with 10GBASE-T > Intel x520-t2 adapters interconnected with a straight-through cat6 rj45 > cable. With mtu 1500, we are achieving aproximately 4 gigabits/s both > directions as demonstrated with iperf. We wanted to test with mtu 9000 to > see whether there would be any difference, but we encountered a problem > setting it. We ran the following commands to alter the MTU to 9000 on the > two machines (fw3 and fw4): > > fw3# ifconfig ix1 192.168.1.100 mtu 9000 > fw4# ifconfig ix1 192.168.1.200 mtu 9000 > > However, instead of getting mtu set to 9000, what we see is the following > message in the kernel output of both machines: > > ix1: Could not setup receive structures > ix1: Could not setup receive structures > > and no traffic getting through. The moment we run: > > fw3# ifconfig ix1 192.168.1.100 mtu 1500 > fw4# ifconfig ix1 192.168.1.200 mtu 1500 > > we see: > > ix1: link state changed to DOWN > ix1: link state changed to UP > > and traffic starts getting through as before. More information about our > hardware is: > > Motherboard: Supermicro H8DGU-F > CPU: AMD 6128 8-core > Memory: 16GB DDR3 > NICs: Intel x520-t2 10GbaseT adapters > > An ifconfig ix1 output for one of the machines: > > fw4# ifconfig ix1 > ix1: flags=8843 metric 0 mtu > 1500 > > options=401bb MTU,VLAN_HWCSUM,TSO4,VLAN_**HWTSO> > ether 00:1b:21:d6:19:51 > inet 192.168.1.200 netmask 0xffffff00 broadcast 192.168.1.255 > nd6 options=29 > media: Ethernet autoselect (autoselect ) > status: active > > > Many thanks for any help/action on this! > > Sincerely, > > Iordan Iordanov > CDF System Administrator > University of Toronto > ______________________________**_________________ > freebsd-bugs@freebsd.org mailing list > http://lists.freebsd.org/**mailman/listinfo/freebsd-bugs > To unsubscribe, send any mail to "freebsd-bugs-unsubscribe@**freebsd.org > " >