[linux-audio-dev] nice [was: jack, low latency and IO]

[Artem Baguinski]

Jens M Andreasen <jens.andreasen at chello.se> writes:

> So if you do:
>
> # nice -10 audioapp [audioapp-options]
>
> .. your audioapp should repaint itself before any less urgent process
> (with normal or slightly high priority) gets a chance at the CPU. JACK
> will still run at (near?) highest priority, so if your audio-processing
> demands 90% CPU there will be not so much repainting going on ...
>

i couldnt decipher man nice / info coreutils nice so i googled to find
out [1] 

    The following nice command executes command-name with a lower
    priority by raising the nice number by 5 units.

    $ /usr/bin/nice -5 command-name

    In the preceding command, the minus sign designates that what
    follows is an option. This command could also be specified as
    follows:

    % /usr/bin/nice -n 5 command-name

    ...

Also I've figured that to lower the nice number I'll need root
priviliges. After patching my kernel [ok, downloading a patched kernel
;-P] to be able jack and friends as my normal self?.. or does this
patch changes the situation? 

[time passes]

no, it doesnt change: 

  [artm at caracolito vlo-mp]$ nice -n 10 ./vlo
  ... vlo runs ...

  [artm at caracolito vlo-mp]$ nice -n -10 ./vlo
  nice: cannot set priority: Permission denied
  ... vlo doesn't run ...

[1] http://docsun.cites.uiuc.edu/sun_docs/C/solaris_9/SUNWaadm/SYSADV2/p78.html

-- 
Artem Baguinski:                         http://www.artm.org/
V2_Lab:                                  http://lab.v2.nl/
V2_ Organisation for the Unstable Media: http://www.v2.nl/