Re: [PATCH update 2] firewire: net: throttle TX queue before runningout of tlabels

[Stefan Richter]

Maxim Levitsky wrote:
> In fact after lot of testing I see that original patch, 
> '[PATCH 4/4] firewire: net: throttle TX queue before running out of
> tlabels' works the best here.
> With AR fixes, I don't see even a single fwnet_write_complete error on
> ether side.

Well, that version missed that the rx path opened up the tx queue again. I.e.
it did not work as intended.

> However the 'update 2' (maybe update 1 too, didn't test), lowers
> desktop->laptop throughput somewhat.
> (250 vs 227 Mbits/s). I tested this many times.
> 
> Actuall raw troughput possible with UDP stream and ether no throttling
> or higher packets in flight count (I tested 50/30), it 280 Mbits/s.

Good, I will test deeper queues with a few different controllers here.  As
long as we keep a margin to 64 so that other traffic besides IPover1394 still
has a chance to acquire transaction labels, it's OK.

> BTW, I still don't understand fully  why my laptop sends only at 180
> Mbits/s pretty much always regardless of patches or TCP/UDP.

If it is not CPU bound, then it is because Ricoh did not optimize the AR DMA
unit as well as Texas Instruments did.
-- 
Stefan Richter
-=====-==-=- =-== -===-
http://arcgraph.de/sr/
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