On Fri, 19 Jun 2009 11:40:14 pm Herbert Xu wrote:

quoted

On the other hand, we're underutilizing the queue to avoid it.  I find
that a little embarrassing.

Here's why I think this is not an issue.  If your NIC is high
bandwidth then your ring is going to have to be huge so the
amount that is underutilised (a 64K packet) is tiny.  If your
NIC is low bandwidth then this is where you often need QoS and
in that case you do *NOT* want to fully utilise the HW queue.

Well, we leave that up to the NIC designer.  It's retro-justification for 
throwing away a few percent of the queue, but the QoS issue is even more in 
the noise.

But I will give in now and change virtio_net to use this substandard API :(

Thanks,
Rusty.