From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jay Vosburgh Subject: Re: [PATCH] bonding: bond_select_queue off by one Date: Thu, 17 Feb 2011 20:41:48 -0800 Message-ID: <22094.1298004108@death> References: <20110218020713.GA9696@linuxace.com> Cc: netdev@vger.kernel.org To: Andy Gospodarek , Phil Oester Return-path: Received: from e37.co.us.ibm.com ([32.97.110.158]:47123 "EHLO e37.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751888Ab1BREmA (ORCPT ); Thu, 17 Feb 2011 23:42:00 -0500 Received: from d03relay03.boulder.ibm.com (d03relay03.boulder.ibm.com [9.17.195.228]) by e37.co.us.ibm.com (8.14.4/8.13.1) with ESMTP id p1I4dOYn007213 for ; Thu, 17 Feb 2011 21:39:24 -0700 Received: from d03av06.boulder.ibm.com (d03av06.boulder.ibm.com [9.17.195.245]) by d03relay03.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p1I4fvrq119136 for ; Thu, 17 Feb 2011 21:41:57 -0700 Received: from d03av06.boulder.ibm.com (loopback [127.0.0.1]) by d03av06.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p1I4kYgg014155 for ; Thu, 17 Feb 2011 21:46:34 -0700 In-reply-to: <20110218020713.GA9696@linuxace.com> Sender: netdev-owner@vger.kernel.org List-ID: Phil Oester wrote: >The bonding driver's bond_select_queue function simply returns >skb->queue_mapping. However queue_mapping could be == 16 >for queue #16. This causes the following message to be flooded >to syslog: > >kernel: bondx selects TX queue 16, but real number of TX queues is 16 > >ndo_select_queue wants a zero-based number, so bonding driver needs >to subtract one to return the proper queue number. Also fix grammar in >a comment while in the vicinity. Andy, can you comment on this? If memory serves, the omission of queue ID zero was on purpose; is this patch going to break any of the functionality added by: commit bb1d912323d5dd50e1079e389f4e964be14f0ae3 Author: Andy Gospodarek Date: Wed Jun 2 08:40:18 2010 +0000 bonding: allow user-controlled output slave selection Ben Hutchings wrote: >This looks basically correct, but it should use the proper functions: > > skb_rx_queue_recorded(skb) ? skb_get_rx_queue(skb) : 0; As Ben points out, skb_rx_queue_recorded, skb_record_rx_queue, et al, do the offset by one internally, but the bond_slave_override function is comparing the slave's queue_id to the skb->queue_mapping. That makes me wonder if this patch is going to mess things up, and if bond_slave_override should also use the skb_rx_queue_recorded, et al, functions. -J >Phil Oester > >Signed-off-by: Phil Oester > > >--- linux-2.6/drivers/net/bonding/bond_main.c.orig 2011-01-30 09:15:09.813843817 -0800 >+++ linux-2.6/drivers/net/bonding/bond_main.c 2011-02-17 18:02:46.919050909 -0800 >@@ -4537,11 +4537,11 @@ > { > /* > * This helper function exists to help dev_pick_tx get the correct >- * destination queue. Using a helper function skips the a call to >+ * destination queue. Using a helper function skips a call to > * skb_tx_hash and will put the skbs in the queue we expect on their > * way down to the bonding driver. > */ >- return skb->queue_mapping; >+ return skb->queue_mapping ? skb->queue_mapping - 1 : 0; > } > > static netdev_tx_t bond_start_xmit(struct sk_buff *skb, struct net_device *dev) --- -Jay Vosburgh, IBM Linux Technology Center, fubar@us.ibm.com