[LAU] Trouble Setting Realtime Priorities with set_rlimits

Chuck Martin v4o42wl02 at sneakemail.com
Sun Oct 9 00:27:20 UTC 2011


I just realized I sent this directly to Clemens, instead of to the list.
I guess it's no big deal, but it was supposed to go to the list.

On Sat, Oct 08, 2011 at 01:20:34PM +0200, Clemens Ladisch clemens-at-ladisch.de wrote:
> On 10/07/2011 08:57 PM, Chuck Martin wrote:
> > % ps -eo pid,rtprio,cls,cmd
> > 16531      -  TS /usr/bin/jackd -v -P70 -t2000 -dalsa -dhw:Intel -r48000 -p1024 -n2 -Xseq -i2 -o2 -I1 -O1
> >
> > It looks like set_rlimits is working until I look at the realtime priority
> > with ps.  What am I doing wrong?
>
> Realtime priorities are shown by ps only for threads that actually are
> using a realtime scheduling policy, and jackd's first thread doesn't.
> Use H to show threads.

Thanks, Clemens.  That explains why I thought I had it working, and
then not working later.  The first time, I used the ps command from
http://subversion.ffado.org/wiki/IrqPriorities (even though I'm not
using ffado), which included the -L option (which also shows threads
like H), but the next time I was doing it from memory, and I neglected
to include the -L option, so it looked like it wasn't working when it
really was.  Well, one advantage to making that mistake is that I've now
learned something more about ps.  I was wondering why there were so few
lines in the output from what I remembered from the first time, and now
I know.

Chuck



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