From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [PATCH 2/2] ixgbe: fix select_queue management (v2) Date: Sat, 21 Mar 2009 12:39:13 -0700 Message-ID: <20090321123914.31cac36c@s6510> References: <20090320214515.5af3a6f4@nehalam> <20090321.003338.103826980.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: "e1000-devel@lists.sourceforge.net" , "netdev@vger.kernel.org" , "Waskiewicz Jr, Peter P" , David Miller , "Kirsher, Jeffrey T" To: "Waskiewicz Jr, Peter P" Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: e1000-devel-bounces@lists.sourceforge.net List-Id: netdev.vger.kernel.org On Sat, 21 Mar 2009 00:43:40 -0700 (Pacific Daylight Time) "Waskiewicz Jr, Peter P" wrote: > On Sat, 21 Mar 2009, David Miller wrote: > > > From: "Waskiewicz Jr, Peter P" > > Date: Fri, 20 Mar 2009 23:21:38 -0700 (Pacific Daylight Time) > > > > > I see your point, but it is a hack in my opinion. The device will have 8 > > > real Tx queues, not 1. I'd much rather go with the original proposal, > > > since if the code in dev_pick_tx() changed, it could silently break ixgbe. > > > > It can't, if you only advertise one transmit queue the kernel > > can never ever choose anything other than queue zero. It's > > impossible. > > > > Stephen's right, you guys don't need your select queue override. > > > > And if you recall I suspected this from the very beginning. > > > > You guys never ever think out of the box, ever... if it's > > not straightforward, you guys won't got for it. That makes > > it very frustrating to get anything done. > > This patch will break DCB in ixgbe. We need all 8 queues, because the > user will be assigning tc filters to the sch_multiq qdisc to get traffic > into priority queues. If we take Stephen's patch and tell the stack we > have 1 real_num_tx_queues, then we get 1 band in sch_multiq, which makes > it impossible to assign traffic to priorities 1 through 8: > How does it make sense to say you have 8 bands, but only use one. ------------------------------------------------------------------------------ Apps built with the Adobe(R) Flex(R) framework and Flex Builder(TM) are powering Web 2.0 with engaging, cross-platform capabilities. Quickly and easily build your RIAs with Flex Builder, the Eclipse(TM)based development software that enables intelligent coding and step-through debugging. Download the free 60 day trial. http://p.sf.net/sfu/www-adobe-com