[LAU] Jack vs. Alsa, PianoTeq demo: Alsa wins!

[Ralf Mardorf]

On Sun, 2011-06-12 at 14:29 +0200, Ralf Mardorf wrote:
> On Sun, 2011-06-12 at 03:46 -0700, James Warden wrote:
> > 
> > --- On Sun, 6/12/11, Ralf Mardorf <ralf.mardorf at alice-dsl.net> wrote:
> > 
> > > From: Ralf Mardorf <ralf.mardorf at alice-dsl.net>
> > > Subject: Re: [LAU] Jack vs. Alsa, PianoTeq demo: Alsa wins!
> > > To: linux-audio-user at lists.linuxaudio.org
> > > Date: Sunday, June 12, 2011, 6:15 AM
> > > On Sun, 2011-06-12 at 11:59 +0200,
> > > Jeremy Jongepier wrote:
> > > > On 06/12/2011 11:44 AM, Ralf Mardorf wrote:
> > > > > What CPU frequency scaling? Is it set to
> > > performance? There's a new
> > > > > nuisance for GNOME desktops on Ubuntu and Debian,
> > > they ignore the
> > > > > kernel's default CPU frequency scaling, they
> > > switch from 'performance'
> > > > > to 'ondemand' for GNOME sessions.
> > > > 
> > > > apt-file search ondemand | grep init.d
> > > > initscripts: /etc/init.d/ondemand
> > > > 
> > > > So at least on Ubuntu the ondemand init script is part
> > > of the 
> > > > initscripts package and has nothing to do with Gnome.
> > > > 
> > > > Best,
> > > > 
> > > > Jeremy
> > > 
> > > 
> > > Thank you :)
> > > 
> > > On Debian it's
> > > 
> > > $ cat /etc/init.d/cpufrequtils
> > > #!/bin/sh
> > > [snip]
> > > GOVERNOR="ondemand"
> > > [snip]
> > > 
> > 
> > 
> > from the same script of debian:
> > 
> > <snip>
> > if [ -f /etc/default/cpufrequtils ] ; then
> >         . /etc/default/cpufrequtils
> > fi
> > 
> > # if not enabled then exit gracefully
> > [ "$ENABLE" = "true" ] || exit 0
> > 
> > if [ -n "$MAX_SPEED" ] && [ $MAX_SPEED != "0" ] ; then
> >         CPUFREQ_OPTIONS="$CPUFREQ_OPTIONS --max $MAX_SPEED"
> > fi
> > 
> > if [ -n "$MIN_SPEED" ] && [ $MIN_SPEED != "0" ] ; then
> >         CPUFREQ_OPTIONS="$CPUFREQ_OPTIONS --min $MIN_SPEED"
> > fi
> > 
> > if [ -n "$GOVERNOR" ] ; then
> >         CPUFREQ_OPTIONS="$CPUFREQ_OPTIONS --governor $GOVERNOR"
> > fi
> > </snip>
> > 
> > The debian way is to have a default config in the directory /etc/default, which cpufrequtils is sourcing if it exists (see script snippet above). So either you make one if you don't have one or get informed before calling such config scheme "idiocy". I don't want to be too hard in my critics but you seem to be a little too noisy too fast. Make sure you RTFM before posting such judgemental comments on distros. 
> > 
> > J.
> 
> But I wish to have the opportunity to chose the frequency scaling e.g.
> by the GNOME panel, just the default should be the kernel's default. I
> don't understand what the script is good for. IMO it only cause pain.
> This script and the behaviour it cause is for a default Debian install
> and IMO this is idiocy. A default can be set by the kernel
> configuration, what's bad with this? The most often cause for xruns for
> the last month I read about, was a bad CPU frequency scaling.
> 
> I'm curios about the cause of "Jack vs. Alsa, PianoTeq demo: Alsa
> wins!".
> 
> I experienced that as soon as jackd is involved, even if a media player
> was ok with ALSA, I got xruns causing audible glitches, already without
> CPU load, while there were never xruns or audible glitches as soon as
> the CPU frequency scaling is set to performance, even for heavy resource
> hungry audio productions. There might be two xruns when I start a
> session, but no additional for the next 48 hours.
> 
> Regards,
> 
> Ralf

PS: What should people read? Why should people read? This isn't a good
OOTB behaviour. It's not relevant for me, because I set up my Debian to
my needs, but I often read about the same issue. For me everything is
ok, but other people have problems and there's no need for those
problems. Even if people are willing to read, thy don't know what to
read.