From mboxrd@z Thu Jan 1 00:00:00 1970 From: Santiago Leon Subject: Re: [PATCH] ibmveth change buffer pools dynamically Date: Fri, 28 Apr 2006 16:53:28 -0500 Message-ID: <44528ED8.7070402@us.ibm.com> References: <1145981998.16266.5.camel@santilt> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from e34.co.us.ibm.com ([32.97.110.152]:8335 "EHLO e34.co.us.ibm.com") by vger.kernel.org with ESMTP id S1751457AbWD1Vzl (ORCPT ); Fri, 28 Apr 2006 17:55:41 -0400 Received: from d03relay04.boulder.ibm.com (d03relay04.boulder.ibm.com [9.17.195.106]) by e34.co.us.ibm.com (8.12.11.20060308/8.12.11) with ESMTP id k3SLteOX008986 for ; Fri, 28 Apr 2006 17:55:40 -0400 Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d03relay04.boulder.ibm.com (8.12.10/NCO/VER6.8) with ESMTP id k3SLteIH172316 for ; Fri, 28 Apr 2006 15:55:40 -0600 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.12.11/8.13.3) with ESMTP id k3SLtet1020863 for ; Fri, 28 Apr 2006 15:55:40 -0600 To: jgarzik@pobox.com, netdev@vger.kernel.org In-Reply-To: <1145981998.16266.5.camel@santilt> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Santiago Leon wrote: > This patch provides a sysfs interface to change some properties of the > ibmveth buffer pools (size of the buffers, number of buffers per pool, > and whether a pool is active). Ethernet drivers use ethtool to provide > this type of functionality. However, the buffers in the ibmveth driver > can have an arbitrary size (not only regular, mini, and jumbo which are > the only sizes that ethtool can change), and also ibmveth can have an > arbitrary number of buffer pools > > Under heavy load we have seen dropped packets which obviously kills TCP > performance. We have created several fixes that mitigate this issue, > but we definitely need a way of changing the number of buffers for an > adapter dynamically. Also, changing the size of the buffers allows > users to change the MTU to something big (bigger than a jumbo frame) > greatly improving performance on partition to partition transfers. > > The patch creates directories pool1...pool4 in the device directory in > sysfs, each with files: num, size, and active (which default to the > values in the mainline version). > > Comments and suggestions are welcome... > Jeff, if you don't have any problem with this patch, can you apply it? Thanks, -- Santiago A. Leon Power Linux Development IBM Linux Technology Center