From owner-freebsd-net@FreeBSD.ORG Wed Sep 24 20:15:42 2008 Return-Path: Delivered-To: net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 59DB2106564A; Wed, 24 Sep 2008 20:15:42 +0000 (UTC) (envelope-from jmg@hydrogen.funkthat.com) Received: from hydrogen.funkthat.com (gate.funkthat.com [69.17.45.168]) by mx1.freebsd.org (Postfix) with ESMTP id 2CC4E8FC16; Wed, 24 Sep 2008 20:15:41 +0000 (UTC) (envelope-from jmg@hydrogen.funkthat.com) Received: from hydrogen.funkthat.com (q9vdbeh3hy4bg8gk@localhost.funkthat.com [127.0.0.1]) by hydrogen.funkthat.com (8.13.6/8.13.3) with ESMTP id m8OJrVM0083313; Wed, 24 Sep 2008 12:53:31 -0700 (PDT) (envelope-from jmg@hydrogen.funkthat.com) Received: (from jmg@localhost) by hydrogen.funkthat.com (8.13.6/8.13.3/Submit) id m8OJrV1T083312; Wed, 24 Sep 2008 12:53:31 -0700 (PDT) (envelope-from jmg) Date: Wed, 24 Sep 2008 12:53:31 -0700 From: John-Mark Gurney To: gnn@freebsd.org Message-ID: <20080924195331.GQ783@funkthat.com> Mail-Followup-To: gnn@freebsd.org, net@freebsd.org References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.1i X-Operating-System: FreeBSD 5.4-RELEASE-p6 i386 X-Files: The truth is out there X-URL: http://resnet.uoregon.edu/~gurney_j/ X-Resume: http://resnet.uoregon.edu/~gurney_j/resume.html X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-3.0 (hydrogen.funkthat.com [127.0.0.1]); Wed, 24 Sep 2008 12:53:31 -0700 (PDT) Cc: net@freebsd.org Subject: Re: Proposed patch, convert IFQ_MAXLEN to kernel tunable... 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: Wed, 24 Sep 2008 20:15:42 -0000 George V. Neville-Neil wrote this message on Tue, Sep 23, 2008 at 15:29 -0400: > It turns out that the last time anyone looked at this constant was > before 1994 and it's very likely time to turn it into a kernel > tunable. On hosts that have a high rate of packet transmission > packets can be dropped at the interface queue because this value is > too small. Rather than make a sweeping code change I propose the > following change to the macro and updating a couple of places in the > IP and IPv6 stacks that were using this macro to set their own global > variables. The better solution is to resurrect rwatson's patch that eliminates the interface queue, and does direct dispatch to the ethernet driver.. Usually the driver has a queue of 512 or more packets already, so putting them into a second queue doesn't provide much benefit besides increasing the amount of locking necessary to deliver packets... -- John-Mark Gurney Voice: +1 415 225 5579 "All that I will do, has been done, All that I have, has not."