Subject: Re: [RFC] New driver API to speed up small packets xmits

From: Gagan Arneja <[email-masked]>
Date: Thu, 10 May 2007 14:50:19 -0700

David Miller wrote:

> Right.
> 
> But I think it's critical to do two things:
> 
> 1) Do this when netif_wake_queue() is triggers and thus the
>    TX is locked already.
> 
> 2) Have some way for the driver to say how many free TX slots
>    there are in order to minimize if not eliminate requeueing
>    during this batching thing.

I don't think you can reliably do this. Jumbograms may end up taking 
more than one slot.

> 
> If you drop the TX lock, the number of free slots can change
> as another cpu gets in there queuing packets.

Can you ever have more than one thread inside the driver? Isn't 
xmit_lock held while we're in there?

--
Gagan