A poll - Was: Re: Scaling governor controls

Len Ovens len at ovenwerks.net
Wed Jul 18 21:43:11 UTC 2012

On Wed, July 18, 2012 1:27 am, Ralf Mardorf wrote:
> On Tue, 2012-07-17 at 23:10 -0700, Len Ovens wrote:
>> and turn off pulse->jack bridging
> Anybody using Ubuntu Studio without getting rid of pulse?
> I'm using Ubuntu Studio, but I removed PA.

I leave pulse running. If the system (including PA) is tuned/setup right,
pulse on it's own causes no harm, uses very little CPU while not being
used and uses very little memory. The PA-jack bridge doesn't cause me too
many problems either really... so long as everything is set up right. It
does use more memory and a lot more CPU, but even on my netbook, this
doesn't cause problems _most_ of the time. Set up correctly is the rub. I
had to spend a lot of time working this stuff out. More than one device
seems to be the place where things go wrong. And of course everyone's set
of devices is different and requires a different setup.

For example, an internal card used by pulse with a higher minimum latency
can lock an external/pci device to that limit when PA-jack bridging is
enabled. On my netbook, the internal HDA sound IF can only get -p128 and
interacts with the wireless to give xrun/minute problems. I have an ART
USB IF that with PA-jack bridge turned off can use -p64 without xruns
(assuming everything set up right), but with the PA-jack bridge on my USB
IF won't let jack even start lower than -p128 and the xrun/minute shows up
too. Configuring PA with my HDA "profile" to OFF fixes this. And I can now
use the USB to listen to a utube song through
flash->gstreamer->pulse->jack->alsa->USB just fine... dumb and only done
to test it, but does work.

It is really easy to just yard out PA and lots of people do (I don't blame
them), but for a firewire user, it may be worth while.

The unfortunate thing is that from a ubuntu studio POV it can't be tweaked
right for a good out of the box experience. It has to be set up by the
user. For us this means both good docs (sigh) and a good tool for setting
things up... and the realization that PA redoes lots of things when
ever... a new USB sound device is plugged in, an application requests a
port, etc.

It is quite easy to turn off and on PA-jack bridging and I would suggest
switching it off when not needed for desktop use.

> I won't argue with audio productions, but does anybody use GIMP while
having a call via skype or something similar?

How about using gimp and listening to tunes from where ever? Much more

> IMO PA belongs to "averaged" desktop distros, but not to a distro for
artists. When drawing, I even turn off my fixed-line network.

I think a lot of people (I won't say most) use their computer for more
than one use, they want to use it as a "normal" computer sometimes. But I
agree with switching distractions off while doing these kinds of things.
Quite honestly, anyone half way serious about art will have an old machine
they have upgraded from for doing the desktop thing, including playing BG

> No Pulseaudio + CPU freq scale gov set up to performance are basics for
any art.

We need to be able to configure for the individual then. Also, for some
machines "performance" makes things hot if left for too long.

> Btw. if you wish to use less resources, without getting xruns, perhaps
setting up the CPU freq scale gov to a fixed limited freq will do the
job. AFAIK xruns are caused by changing the speed on demand, but I
suspect that a limit to 1GHz for your 2GHz CPU won't cause issues.

That has been my experience while watching CPU speed vs. xruns. Allowing
the user to select cpu speed for the job sounds like a good idea. I'll
have to find out how :-)  Setting performance is easy, and so is ondemand.
But I don't know how to set half or in between speeds. Anyone know?

Len Ovens

Len Ovens

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