From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Fastabend Subject: Re: [RFC net-next 07/14] Fix intel/ixgbe Date: Wed, 20 Jun 2012 08:30:48 -0700 Message-ID: <4FE1ECA8.1060201@intel.com> References: <1340118848-30978-1-git-send-email-yuvalmin@broadcom.com> <1340118848-30978-8-git-send-email-yuvalmin@broadcom.com> <4FE0A0CD.5050909@intel.com> <1340182514.4604.843.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Alexander Duyck , Yuval Mintz , netdev@vger.kernel.org, davem@davemloft.net, eilong@broadcom.com, Jeff Kirsher To: Eric Dumazet Return-path: Received: from mga14.intel.com ([143.182.124.37]:12750 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752654Ab2FTPau (ORCPT ); Wed, 20 Jun 2012 11:30:50 -0400 In-Reply-To: <1340182514.4604.843.camel@edumazet-glaptop> Sender: netdev-owner@vger.kernel.org List-ID: On 6/20/2012 1:55 AM, Eric Dumazet wrote: > On Tue, 2012-06-19 at 08:54 -0700, Alexander Duyck wrote: > >> This patch doesn't limit the number of queues. It is limiting the >> number of interrupts. The two are not directly related as we can >> support multiple queues per interrupt. >> >> Also this change assumes we are only using receive side scaling. We >> have other features such as DCB, FCoE, and Flow Director which require >> additional queues. >> > > Yet, it would be good if ixgbe doesnt allocate 36 queues on a 4 cpu > machine. > > "tc -s class show dev eth0" output is full of not used classes. > > > We do this for the DCB/FCoE/RSS/Flow Director case where we want to use multiple queues per traffic class (802.1Qaz). As it is now we have to set the max queues at alloc_etherdev_mq() time so we use a max of (num_cpu * max traffic classes) + num_cpu The last num_cpu is in error and I have a patch in JeffK's tree to remove this. In many cases it seems excessive but sometimes it is helpful. .John