Re: [Discuss-gnuradio] usrp_siggen.py underruns

[Eric Blossom]

On Wed, Feb 11, 2009 at 07:35:10PM +0100, Dominik Auras wrote:
> Hi!
>
> I am currently observing an odd behavior of usrp_siggen.py.
>
> When I start the program as follows
>
> ./usrp_siggen.py -f 2.40G -i 16 --gaussian
>
> there are a lot of underruns (uU). However, for all other signal  
> generation options except gaussian, it works fine (i.e. const, sine,  
> uniform). Just to see, I have modified usrp_siggen to enable realtime  
> scheduling. It didn't make the underruns go away.
> My /etc/security/limits.conf contains the line

> @usrp           -       rtprio          90

> as suggested by a recent post to mailing list (though I increased the  
> maximum priority). libgruel realtime functions sets the priority -30  
> (checked with top). CPU usage is ~ 103%.

That won't help.  The problem is that the gaussian RNG is really slow.
You'll need to figure out how to make it faster.

Eric