Subject: Re: [PATCH 3/3] NET: [SCHED] Qdisc changes and sch_rr added for multiqueue

From: Patrick McHardy <[email-masked]>
Date: Fri, 22 Jun 2007 20:53:19 +0200

Patrick McHardy wrote:
> Waskiewicz Jr, Peter P wrote:
> 
>>Thought about this more last night and this morning.  As far as I can
>>tell, I still need this.  If the qdisc gets loaded with multiqueue
>>turned on, I can just use the value of band to assign
>>skb->queue_mapping.  But if the qdisc is loaded without multiqueue
>>support, then I need to assign a value of zero to queue_mapping, or not
>>assign it at all (it will be zero'd out before the call to ->enqueue()
>>in dev_queue_xmit()).  But I'd rather not have a conditional in the
>>hotpath checking if the qdisc is multiqueue; I'd rather have the array
>>to match the bands so I can just do an assignment.
>>
>>What do you think?
> 
> 
> 
> I very much doubt that it has any measurable impact. You can
> also add a small inline function
> 
> void skb_set_queue_mapping(struct sk_buff *skb, unsigned int queue)

OK I didn't really listen obviously :) A compile time option
won't help. Just remove it and assign it conditionally.