From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [PATCH 2/3][NET_BATCH] net core use batching Date: Tue, 09 Oct 2007 15:04:23 -0400 Message-ID: <470BD0B7.4070607@garzik.org> References: <1191886845.4373.138.camel@localhost> <470AD5D7.1070000@garzik.org> <20071008.184126.124062865.davem@davemloft.net> <470AE373.9020207@garzik.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: David Miller , hadi@cyberus.ca, krkumar2@in.ibm.com, johnpol@2ka.mipt.ru, herbert@gondor.apana.org.au, kaber@trash.net, shemminger@linux-foundation.org, jagana@us.ibm.com, Robert.Olsson@data.slu.se, rick.jones2@hp.com, xma@us.ibm.com, gaagaan@gmail.com, netdev@vger.kernel.org, rdreier@cisco.com, mcarlson@broadcom.com, mchan@broadcom.com, general@lists.openfabrics.org, tgraf@suug.ch, randy.dunlap@oracle.com, sri@us.ibm.com To: "Waskiewicz Jr, Peter P" Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:60221 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752265AbXJITFB (ORCPT ); Tue, 9 Oct 2007 15:05:01 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Waskiewicz Jr, Peter P wrote: >> IMO the net driver really should provide a hint as to what it wants. >> >> 8139cp and tg3 would probably prefer multiple TX queue >> behavior to match silicon behavior -- strict prio. > > If I understand what you just said, I disagree. If your hardware is > running strict prio, you don't want to enforce strict prio in the qdisc > layer; performing two layers of QoS is excessive, and may lead to > results you don't want. The reason I added the DRR qdisc is for the Si > that has its own queueing strategy that is not RR. For Si that > implements RR (like e1000), you can either use the DRR qdisc, or if you > want to prioritize your flows, use PRIO. A misunderstanding, I think. To my brain, DaveM's item #2 seemed to assume/require the NIC hardware to balance fairly across hw TX rings, which seemed to preclude the 8139cp/tg3 style of strict-prio hardware. That's what I was responding to. As long as there is some modular way to fit 8139cp/tg3 style multi-TX into our universe, I'm happy :) Jeff