Re: Realtime Kernel, UHD 4.0, GNURadio

[Marcus D. Leech]

On 2022-05-05 14:52, Dobler, Anton wrote:

Dear community,

I am running UHD 4.0 and GNURadio 3.10 on a Ubuntu 20.04 with a N310 as a SDR.

When I execute the benchmark_rate example with DPDK enabled, I do not see any under- or overruns even with the sampling rate set to 125 MHz, however using GNURadio - DPDK enabled here as well - I do not achieve that high sampling rate. The limit seems to be around 30MHz though.

    There's a very very large difference between the amount of "stuff"
    done with a typical Gnu Radio flow-graph, and the "benchmark_rate"
    example.  The
      benchmark_rate example measures the *absolute maximum* you can
    expect to achieve while simply consuming/emitting samples that you
    otherwise do
      nothing with.  Gnu Radio, even for a "trivial" example flow-graph
    tends to "touch" samples a lot more than benchmark_rate would.  Just
    the nature of
      the framework.

Do you know, apart from using taskset and isolcpus any other possibility to achieve higher sampling rates?

Would it be an option to use the realtime kernel available for Ubuntu 20.04 and is this kernel compatible with GNURadio?

    I have never found the real-time options to be globally optimal,
    but, your mileage may vary.

Any help also with regards to the usage of taskset and isolcpus would be highly appreciated!

Thank you in advance!

BR,

Anton