problems with b43 and greedy traffic

[francesco.gringoli at ing.unibs.it]

On Jun 11, 2011, at 11:46 PM, Michael Büsch wrote:

> On Sat, 11 Jun 2011 23:17:50 +0200
> Rafał Miłecki <zajec5 at gmail.com> wrote:
>> iperf says to send UDP stream with speed 34.4 Gb/s.
> 
> iperf in UDP mode did never really work for me on any hardware. What about TCP? Does that work?
TCP partially hides this problem when you run TCP sessions toward a remote host. Anyway if you put some printk in b43_tx_work you will see that some TCP segments are discarded by it trying to send packets to the dma even if the rings are full. This prevents packets to queue up correctly in the qdisc, so shaping traffic through a b43 interface becomes really difficult.

BR,
-Francesco