From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: Re: [PATCH] NET: Multiqueue network device support. Date: Mon, 11 Jun 2007 20:05:38 +0200 Message-ID: <466D8EF2.50203@trash.net> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Cc: davem@davemloft.net, netdev@vger.kernel.org, jeff@garzik.org, "Kok, Auke-jan H" To: "Waskiewicz Jr, Peter P" Return-path: Received: from stinky.trash.net ([213.144.137.162]:48473 "EHLO stinky.trash.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753272AbXFKSIL (ORCPT ); Mon, 11 Jun 2007 14:08:11 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Waskiewicz Jr, Peter P wrote: >>I think we can reuse skb->priority. Assuming only real >>hardware devices use multiqueue support, there should be no user of >>skb->priority after egress qdisc classification. The only reason >>to preserve it in the qdisc layer is for software devices. > > > That would be oustanding. > > >>Grepping through drivers/net shows a few users, bot most seem >>to be using it on the RX path and some use it to store internal data. > > > Thank you for hunting this down. I will test on my little environment > here to see if I run into any issues. I think grepping will help more than testing :) The only issue I can see is that packets going to a multiqueue device that doesn't have a multiqueue aware qdisc attached will get a random value. So you would have to conditionally reset it before ->enqueue. Another question is what to do about other hard_start_xmit callers. Independant of which field is used, should the classification that may have happend on a different device be retained (TC actions again)?