Re: [Discuss-gnuradio] Debugging overruns

[Eric Blossom]

On Sat, Jan 27, 2007 at 01:47:09PM -0800, Dan Halperin wrote:
> Hi,
> 
> I'm trying to figure out what the right tools are to debug problems like
> overruns in the USRP. I have a modified version of tunnel.py running (I
> basically took out the tun/tap interfaces and added my own on top), and
> I'm finding things like after exactly 700 128-byte packets I see an
> overrun - every time I run the program. I've cut out as much as I can
> from my code - removing debug prints, etc, but the problem persists. Do
> you have any suggestions as to where to start looking?
> 
> Thanks,
> 
> Dan

overruns or underruns?

Underruns are to be expected with tunnel.py, assuming that you're not
feeding it data constantly.  

(When the in-band signaling stuff is complete, we'll have a more
sensible interpretation for the underrun case.  It'll only
report a problem if it occurs within a packet, not between packets.)

Are you running with real time scheduling enabled?  If you run
tunnel.py as root (or having CAP_SYS_NICE) it'll be enabled (currently
only implemented on system that implement sched_setscheduler.)

Have you enabled logging? Turn it off.

Linux or some other OS?

Does the unmodified tunnel.py exhibit the same behavior?

Does benchmark_tx.py / benchmark_rx.py work without over/underruns?

Eric