Re: [Discuss-gnuradio] [USRP-users] Gnu Radio apps freezes (locks up)

[Tom Rondeau]

On Thu, Mar 29, 2012 at 6:04 AM, Rickard Radio <address@hidden> wrote:
>
> On Mar 29, 2012, at 3:26 AM, Tom Rondeau wrote:
>
>> On Wed, Mar 28, 2012 at 10:02 AM, Rickard Radio <address@hidden> wrote:
>>> Hi list,
>>>
>>> After I upgraded to latest Gnu Radio 3.5.2, and latest UHD (and images), GR 
>>> applications just freeze when running. No warnings, error messages or 
>>> overflows etc. Just freeze.
>>> A simple FFT plot directly on received samples from the USRPN210 just 
>>> freezes after some seconds, or minutes (depending on the sample rate), 
>>> although the load on the machine is not high. Need to kill GR-app and 
>>> restart it, with the same problem occurring again.
>>>
>>> This has never been a problem with earlier versions of GR/UHD, from about 6 
>>> months ago.
>>> The freezing happens quicker with high sample rate setting but also with 
>>> lower, eventually. No overflows happen (which was possible to get before 
>>> with too high sample rates or load, etc.)
>>>
>>> The USRPN210 stops sending samples to the computer at the same moment as 
>>> GnuRadio freezes (as observed on the system monitor).
>>>
>>> Same thing happen on two identical laptops running Ubuntu 10.10 (also 
>>> upgraded it from 10.04). Not sure if its a strict GnuRadio problem (since 
>>> it worked before), UHD, or some problem with the Ubuntu Linux 10.10. It 
>>> work(ed) flawlessly with another machine on OSX (before I tried to upgrade 
>>> GR on it but then got stuck...) with identical UHD version and images.
>>>
>>> Installation of UHD+GnuRadio with the automatic linux script runs without 
>>> any problems, as before, no errors or warnings.
>>>
>>> Any de-freezing help or clues appreciated!
>>>
>>> Rickard
>>
>> Rickard,
>>
>> Just to be clear. When you install 3.5.2 from the tarball, it freezes.
>> When you use the build-gnuradio, everything works fine?
>>
>> What's your machine?
>>
>> Tom
>
> Tom,
>
> The installation with build-gnuradio script works just fine, as before (no 
> tarballs).
> Same result on both laptops, Acer Aspire TimelineX with i3 processors (2.26 
> GHz),  running Ubuntu 10.10.
> I did not have this problem earlier with Ubuntu 10.04. Or on a Mac with OS X 
> (with the source from git).  Could Ubuntu 10.10 cause the problem somehow?
>
> Note: Halting/freezing only happens when running an application (with the 
> N210) as a receiver. (Not transmitter, see below.)
> The flow of receiving samples just halts after a while and the application 
> freezes/halts (as a consequence).
> This happen sooner with high sampling rate (after a few seconds with 25MSPS), 
> but eventually also with a bit lower sample rates. The CPU's are not 
> overwhelmed (< 50%).
> It happens even if the UHD usrp source is connected directly to a null sink 
> only. I do not get any overflows before the halt.
> In fact, I cannot even provoke a continuos stream of overflows since the 
> reception just halts instead of producing overflows, which was the result 
> earlier.
>  GnuRadio itself does not freeze as a whole (like the grc in the background), 
> just the running application, which I then need to abort.
>
> Strangely enough, this "freezing/halting" does NOT happen when transmitting, 
> correspondingly, even with high transmit sample rates such as 25 MSPS (or now 
> possible even with 50MSPS with 8 bit/samples!). Then it works just fine - 
> even without underruns (when using just a file source).
>
>
> / Rickard


Rickard,

Thanks for the data. Unfortunately, I have no idea what to make of
this. There isn't that much difference between the last release
(3.5.2.1) and what you get using the build-gnuradio script. That just
grabs the latest master version from our git repo, and we haven't done
all that much since the release. That really doesn't make a lot of
sense.

How's your git? If you're comfortable doing so, can you check out the
v3.5.2.1 tag on git and try that one instead of the tarball release?

Thanks,
Tom