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Date: Mon, 26 Feb 2007 17:03:17 -0800 (PST)
Message-Id: <20070226.170317.41636240.davem@davemloft.net>
To: auke-jan.h.kok@intel.com
Cc: jgarzik@pobox.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
       peter.p.waskiewicz.jr@intel.com, jesse.brandeburg@intel.com,
       auke@foo-projects.org, john.ronciak@intel.com
Subject: Re: [PATCH 1/2] NET: Multiple queue network device support
From: David Miller <davem@davemloft.net>
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From: "Kok, Auke" <auke-jan.h.kok@intel.com>
Date: Thu, 08 Feb 2007 16:09:50 -0800

> From: Peter Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
> 
> Added an API and associated supporting routines for multiqueue network
> devices.  This allows network devices supporting multiple TX queues to
> configure each queue within the netdevice and manage each queue
> independantly.  Changes to the PRIO Qdisc also allow a user to map
> multiple flows to individual TX queues, taking advantage of each queue
> on the device.
> 
> Signed-off-by: Peter Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
> Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>

Thanks for posting this.

I was wonding if it would be better to have the ->enqueue() perform
the mapping operation, store the queue index selected inside of the
skb, and just use the normal ->hard_start_xmit() to send the packet
out?

The only thing to take care of is the per-queue locking, but that
should be easily doable.

We might be able to do this even without making sk_buff any larger.
For example, I suppose skb->priority might be deducable down to
a u16.  After a quick audit I really cannot see any legitimate use
of anything larger than 16-bit values, but a more thorough audit
would be necessary to validate this.