[LAU] unable to set scheduling priority with rt kernel

Florian Schmidt mista.tapas at gmx.net
Mon Oct 29 14:30:25 EDT 2007


On Monday 29 October 2007, Chuckk Hubbard wrote:
> On 10/25/07, Florian Schmidt <mista.tapas at gmx.net> wrote:
> > On Wednesday 24 October 2007, Chuckk Hubbard wrote:
> > > On 10/24/07, Florian Schmidt <mista.tapas at gmx.net> wrote:
> > > > if you run
> > > >
> > > > sudo chrt -fp 70 `pidof "jackd"`
> > > >
> > > > as non root without using sudo
> > > >
> > > > chrt -fp 70 `pidof "jackd"`
> > > >
> > > > do you get an error?
> > >
> > > Why no I don't!  And it changes priority.  I swore it didn't work
> > > before when I tried it.  I've just now added "session required
> > > /lib/security/pam_limits.so" to /etc/pam.d/common-session, as others
> > > suggested, maybe that did something?
> > > So does that mean the -P flag can never set priority 70?  I got it from
> > > your site!
> >
> > Well, if chrt works now without sudo, try running
> >
> > jackd -R -P 70 -d alsa ...
> >
> > again. It should work now, too..
>
> Update: I just discovered that running jackd -R -P 70 -dalsa -P -p256 -n2
> -r44100 as ROOT doesn't even set priority 70.  jackd then runs as a root
> process with priority 20, according to both chrt and top.
> Apparently my system is not able to run anything higher than 20 priority;
> does this mean my kernel is misconfigured, or might it be something else?
> -Chuckk

install htop

run it

press f2 [setup]
-> Display Options
  -> uncheck "Hide userland threads"
  -> uncheck "Hide kernel threads"

Do you see all 4 jack threads now? 

-- 
Palimm Palimm!
http://tapas.affenbande.org



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