QT GUI Frequency Sink CPU usage

GNU Radio
#1

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 L.

–
View this message in context:
http://gnuradio.4.n7.nabble.com/QT-GUI-Frequency-Sink-CPU-usage-tp46251.html
Sent from the GnuRadio mailing list archive at Nabble.com.

#2

On Mon, Feb 10, 2014 at 12:54 AM, Jim L. [email protected]
wrote:

python: 5%
xorg: 9%

Could this be a bug?

Regards,

Jim L.

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

#3

On Tue, Feb 11, 2014 at 11:02 AM, Tom R. [email protected] wrote:

QT GUI Sink CPU usage
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