[PD] switch~ & cputime climbing

Dafydd Hughes dafydd61 at gmail.com
Thu Jun 7 22:19:11 CEST 2007


Ha!  Thanks, Kyle.  Actually, it's mostly based on David Golightly's
granular delay, which is a really elegant piece of work, and without
which I never would have been able to try this.  I ended up rewriting
it without the scheduler, and changed some other stuff too.  I'm
halfway through another, but here's the most recent, which should be
way more efficient and talks OSC.  Disclaimer: it's still pretty old
and has lots of my dumb patching!

http://sideshowmedia.ca/zips/lois.zip

So strange that weirdness isn't getting duplicated.  I wonder what's up...

cheers
dafydd

On 6/6/07, Kyle Klipowicz <kyleklip at gmail.com> wrote:
> No problems here on a G4 PowerBook, but this delay is pretty rad, do
> you have any more?!
>
> ~Kyle
>
> On 6/6/07, Dafydd Hughes <dafydd61 at gmail.com> wrote:
> > Hi folks
> >
> > Okay - I think this is more or less the same patch, with a couple of
> > minor changes:
> >
> > http://sideshowmedia.ca/cputest.zip
> >
> > Oddly, I can't reproduce my original problem, although some
> > fascinating new things have shown up.  Perhaps it was a PowerPC issue?
> >  (I'm now on a MacBook)
> >
> > Try switching on & off the main dsp and test_lois.  On my computer
> > (extended test 6 - delays not working in later tests) cputime goes up
> > slightly when I turn dsp off.
> >
> > I never figured out exactly why the climb was happening, but I found
> > that it happened when I turned off dsp in the abstraction, but left
> > the non-dsp elements running, ie continually trying to pass messages
> > to line~ and vd~ objects etc.  Switching off the mechanics when
> > switching off dsp solved it for me.
> >
> > I hope this helps!  I'd love to hear if this test patch climbs on a
> > PowerPC still.
> >
> > cheers
> > dafydd
> >
> > On 6/6/07, Phil Stone <pkstone at ucdavis.edu> wrote:
> > > Hi Derek,
> > >
> > > I'm not positive about this, but I think I've traced the CPU-climb to
> > > the [moog~] filter.  It has an odd behavior that can be broken into
> > > three phases:
> > >
> > > 1) no audio greater than zero amplitude has passed through it yet (since
> > > patch load)
> > > 2) audio of some amplitude >0 passes through
> > > 3) audio passing through goes back to zero amplitude
> > >
> > > At 3) (or, more accurately, several seconds after), its CPU usage climbs
> > > fairly dramatically, only to drop down again when the amplitude of the
> > > audio goes up again.   Something in the filter model doesn't like zero
> > > amplitude, but only after it's first processed something greater than zero.
> > >
> > > I meant to test this more rigorously, but got sidetracked.  At any rate,
> > > when I switch~ the [moog~] filter out, CPU usage holds steady.  To be
> > > clear, I don't think this relates to [switch~].  I'm on a Macbook Pro,
> > > currently running 0.39rc2.
> > >
> > > Phil
> > >
> > >
> > >
> > > Derek Holzer wrote:
> > > > Hi Phil,
> > > >
> > > > just to keep this in people's minds... I have exact same problem
> > > > described in these emails with my Particle Chamber granular synthesis
> > > > patch. It has 32 "switch~ed" voices. Using one instance seems to be
> > > > OK, but two or more leads to exponentially-growing CPU usage that
> > > > eventually makes PD unresponsive to the GUI (and eventually would
> > > > probably crash PD if I let it go on...) I guess this could relate to
> > > > the "isn't the GUI supposed to have lower priority than    process?"
> > > > thread, since this particular problem makes PD a bit unusable for the
> > > > kind of performances I want to be doing with it. The fact that PD
> > > > lacks a usable voice-allocation method (i.e. CPU resources can be
> > > > allocated and de-allocated to a voice, something which switch~ has a
> > > > bug with, and which Nqpoly~ and so on does not do at all) means that I
> > > > must start looking into SuperCollider to work with my polyphonic
> > > > granular synthesis stuff. Sad but true...
> > > >
> > > > d.
> > > >
> > > > Phil Stone wrote:
> > > >> Hi,
> > > >>
> > > >> I'm getting a slow-but-steady climbing CPU when running some
> > > >> synthesis patches.  I (like the poster below) have sub-modules that
> > > >> can be switch~ed on and off.  An archive search turned up the
> > > >> following un-replied post:
> > > >>> Hi all
> > > >>>
> > > >>> Okay.  I'm stumped.
> > > >>>
> > > >>> Recently, I've noticed that my cpu meter has been steadily rising.
> > > >>> I  think I may have found the culprit.
> > > >>>
> > > >>> A while back I thought I'd put a power switch (just a switch~
> > > >>> object)  on my poor-man's granular delay line, as my performance
> > > >>> patches are  getting a bit bulky.
> > > >>>
> > > >>> Try this (if you have the time):
> > > >>>
> > > >>> http://www.sideshowmedia.ca/cputest.zip
> > > >>>
> > > >>> cputest.pd: (needs expr, but I think that's all)
> > > >>>
> > > >>> 1. turn on audio in pd, but leave the power (p toggle) in "lois"
> > > >>> off.  Watch the cpu meter climb (over a period of 5 minutes or so -
> > > >>> the toggle prints the cputime every 10 seconds).  On my computer
> > > >>> (G4  Powerbook, HCS extended 0.38.4) it starts around 5% and hits
> > > >>> 10%  after 5 minutes.
> > > >>>
> > > >>> 2. Do the same with "lois" on.  For me, cpu hovers around 13-14%.
> > > >>> No  increase.
> > > >>>
> > > >>> 3. Repeat step 1.  After 10-15 minutes, cputime is higher than with
> > > >>> "lois" on.  Switch "lois" on, and cpu drops.  Huh?
> > > >>>
> > > >>> I have no idea what's going on, but am I missing something
> > > >>> important?  Thanks in advance.
> > > >>>
> > > >>> cheers
> > > >>> dafydd
> > > >>>
> > > >>
> > > >> Does anybody have any insight on this?  I don't remember this
> > > >> happening until fairly recently, but don't know if it dates to when I
> > > >> started switch~ing modules.  I'm currently running 0.39.2-extended
> > > >> RC1 on a MacBook Pro.
> > > >>
> > > >>
> > > >> Phil Stone
> > > >>
> > > >> _______________________________________________
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> > > >>
> > > >
> > >
> > >
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> >
> >
> > --
> > www.sideshowmedia.ca
> > skype: chickeninthegrass
> >
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>
>
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