Re: [PATCH] bonding: bond_select_queue off by one
From: Jay Vosburgh <hidden>
Date: 2011-02-18 04:42:00
Phil Oester [off-list ref] 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 [off-list ref]
Date: Wed Jun 2 08:40:18 2010 +0000
bonding: allow user-controlled output slave selection
Ben Hutchings [off-list ref] 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
quoted hunk ↗ jump to hunk
Phil Oester Signed-off-by: Phil Oester <redacted>--- 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