Re: [Discuss-gnuradio] QT GUI Frequency Sink CPU usage

[Tom Rondeau]

On Tue, Feb 11, 2014 at 11:02 AM, Tom Rondeau <address@hidden> wrote:
> On Mon, Feb 10, 2014 at 12:54 AM, Jim Larsen <address@hidden> wrote:
>> The CPU usage of the QT GUI Frequency Sink is much higher than the QT GUI
>> Sink. I made a test flow graph with a noise source, throttle, and QT GUI
>> Sink using default parameters. I am running GNU Radio version 3.7.0, Xubuntu
>> 13.10, on a MacBook with 2.4 Ghz Intel dual core CPU.
>>
>> QT GUI Frequency Sink CPU usage
>> python: 43%
>> xorg: 58%
>>
>> QT GUI Sink CPU usage
>> python: 5%
>> xorg: 9%
>>
>> Could this be a bug?
>>
>> Regards,
>>
>> Jim Larsen
>
> Yes, I'm seeing the same thing. There's no good reason for that to be
> happening, though. Also, when using performance monitor, I'm seeing
> that the qt frequency sink actually takes a smaller percent of the
> overall runtime than the the qt sink. So whatever is happening is
> occurring outside of the block itself (in the QT and X systems), so
> performance monitor doesn't pick it up.
>
> Yes, this seems like a bug and should definitely be looked into.
>
> Tom


Hey Jim,

I found the issue. It was an excess usage of timers that was calling
into the x system way too often, apparently. I've just pushed an
update that address the issue and makes a dramatic improvement in the
CPU usage.

Thanks for pointing this out!

Tom