[PD] what makes Pd-extended 0.43 so CPU-hungry?

[katja]

On OSX I use 'Activity Monitor' for quick check of CPU load and
Shark.app for serious performance profiling, but for GNU/Linux I don't
know a good equivalent of Shark. So on Debian I just start top, and
for my live performance setup which does ~40% CPU load with
Pd-extended 0.42, it is ~60% with 0.43. Top makes distinction between
'pdextended' and pd-gui, but heavy GUI use is reflected in increasing
percentages for Xorg process as well. However, the load-increase with
Pd-extended 0.43 is on account of the pdextended process (with my
setups at least). Wish I could track that down to specific functions
like with Shark.app.

In the case of OSX it was clearly the Apple dsp function calls
consuming a great deal of CPU time, which could be avoided by using an
external soundcard instead of the internal card, and Jack instead of
PortAudio.

I've tried to use Oprofile on Debian, but this gives me a kernel
failure soon as I start sampling. Does anyone know of a fine
performance profiler for GNU/Linux?

Katja



On 5/4/12, Hans-Christoph Steiner <hans at at.or.at> wrote:
>
> I honestly don't know the cause, and haven't really checked on numbers.  I
> mostly work on my four year old laptop, and test by running patches I know
> (solitude is a good test of heavy CPU usage, it won't run on a machine less
> than 1.6GHz, from my experience).
>
> As for drawing operations like anti-aliasing, those would not show up in the
> 'pd' process, but rather the 'pd-gui' process, since that's the Tk part.
>
> Are you seeing the CPU increase in the 'pd' process?  How are you measuring
> this?
>
> .hc
>
> On May 4, 2012, at 9:31 AM, katja wrote:
>
>> Hello,
>>
>> I've installed Pd-extended 0.43 versions (Linux and OSX) from the
>> autobuilds several times in the past year. The latest builds seem to
>> work fine in many aspects, but they are still so CPU-hungry: ~ 50%
>> more than Pd-extended 0.42. How come?
>>
>> A while ago, the new PortAudio version was blamed
>> (http://www.mail-archive.com/pd-list@iem.at/msg50357.html). Indeed,
>> using Jack solves the load difference for OSX.
>>
>> But on Debian I also observe a 50% load increase for the new
>> Pd-extended. No matter if ALSA or Jack is used. Does anyone have
>> similar observations with Linux builds?
>>
>> BTW, I'm happy with Tk 8.5's antialiased font! Initially, I feared
>> that antialiasing was responsible for increased load on Debian, but
>> disabling GUI updates did not make noticeable difference. It seems
>> that antialiasing is done rather efficiently, the performance drop
>> must be somewhere else.
>>
>> Katja
>>
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>