From owner-freebsd-doc@FreeBSD.ORG Thu Jan 6 18:20:06 2011 Return-Path: Delivered-To: freebsd-doc@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 10E19106564A for ; Thu, 6 Jan 2011 18:20:06 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id C27D48FC18 for ; Thu, 6 Jan 2011 18:20:05 +0000 (UTC) Received: from freefall.freebsd.org (localhost [127.0.0.1]) by freefall.freebsd.org (8.14.4/8.14.4) with ESMTP id p06IK5ft067348 for ; Thu, 6 Jan 2011 18:20:05 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.4/8.14.4/Submit) id p06IK5OZ067345; Thu, 6 Jan 2011 18:20:05 GMT (envelope-from gnats) Resent-Date: Thu, 6 Jan 2011 18:20:05 GMT Resent-Message-Id: <201101061820.p06IK5OZ067345@freefall.freebsd.org> Resent-From: FreeBSD-gnats-submit@FreeBSD.org (GNATS Filer) Resent-To: freebsd-doc@FreeBSD.org Resent-Reply-To: FreeBSD-gnats-submit@FreeBSD.org, Tom Judge Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 69F6D1065672 for ; Thu, 6 Jan 2011 18:13:31 +0000 (UTC) (envelope-from tom@tomjudge.com) Received: from tomjudge.vm.bytemark.co.uk (tomjudge.vm.bytemark.co.uk [80.68.91.100]) by mx1.freebsd.org (Postfix) with ESMTP id 159FE8FC0A for ; Thu, 6 Jan 2011 18:13:30 +0000 (UTC) Received: from localhost (localhost.localdomain [127.0.0.1]) by tomjudge.vm.bytemark.co.uk (Postfix) with ESMTP id C232511C03A; Thu, 6 Jan 2011 18:13:29 +0000 (GMT) Received: from tomjudge.vm.bytemark.co.uk ([127.0.0.1]) by localhost (tomjudge.vm.bytemark.co.uk [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Fr1VzJKduqaO; Thu, 6 Jan 2011 18:13:27 +0000 (GMT) Received: from tinderbox.home.tomjudge.com (unknown [192.168.200.5]) by tomjudge.vm.bytemark.co.uk (Postfix) with SMTP id B58A448C6B; Thu, 6 Jan 2011 18:13:25 +0000 (GMT) Received: by tinderbox.home.tomjudge.com (sSMTP sendmail emulation); Thu, 06 Jan 2011 18:17:50 +0000 Message-Id: <20110106181325.B58A448C6B@tomjudge.vm.bytemark.co.uk> Date: Thu, 06 Jan 2011 18:17:50 +0000 From: "Tom Judge" To: FreeBSD-gnats-submit@FreeBSD.org X-Send-Pr-Version: 3.113 Cc: jfv@FreeBSD.org, gjb@FreeBSD.org Subject: docs/153738: [patch] Docuement requirement to alter some sysctls when using igb(4) with jumbo frames. X-BeenThere: freebsd-doc@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: Tom Judge List-Id: Documentation project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 06 Jan 2011 18:20:06 -0000 >Number: 153738 >Category: docs >Synopsis: [patch] Docuement requirement to alter some sysctls when using igb(4) with jumbo frames. >Confidential: no >Severity: non-critical >Priority: low >Responsible: freebsd-doc >State: open >Quarter: >Keywords: >Date-Required: >Class: change-request >Submitter-Id: current-users >Arrival-Date: Thu Jan 06 18:20:05 UTC 2011 >Closed-Date: >Last-Modified: >Originator: Tom Judge >Release: FreeBSD 8.1-STABLE amd64 >Organization: >Environment: System: FreeBSD tinderbox.home.tomjudge.com 8.1-STABLE FreeBSD 8.1-STABLE #0 r213720: Tue Oct 12 14:02:02 UTC 2010 tj@tinderbox.home.tomjudge.com:/usr/obj/usr/src/sys/GENERIC amd64 >Description: The attach patch (against current) documents the requirement to tune nmbcluster releated tuneables when using jumbo frames. This tuning requirement is not obvious from error messages reported by the driver or the output of netstat -m. Reviewed by: gjb@ Tom >How-To-Repeat: >Fix: --- igb.4.txt begins here --- Index: igb.4 =================================================================== --- igb.4 (revision 216409) +++ igb.4 (working copy) @@ -161,6 +161,18 @@ If set to 1, enable Adaptive Interrupt Moderation. The default is to enable Adaptive Interrupt Moderation. .El +.Pp +If using jumbo frames with this driver, it is worth +configuring the following sysctls, as the default settings +for the card will require more resources than the default. +.Bl -tag -width indent +.It Va kern.ipc.nmbclusters +The maximum number of mbuf clusters allowed. +.It Va kern.ipc.nmbjumbo9k +The maximum number of mbuf 9k jumbo clusters allowed. +Increasing this to allow for at least 8192 extra clusters +per interface should allow for an mtu of 8192. +.El .Sh DIAGNOSTICS .Bl -diag .It "igb%d: Unable to allocate bus resource: memory" --- igb.4.txt ends here --- >Release-Note: >Audit-Trail: >Unformatted: