[PlanetCCRMA] How does pam.d security settings work?

[Fernando Lopez-Lezcano]

On Sun, 2009-12-13 at 09:32 +0100, Simon Lewis wrote:
> This is not a bug request - I would simply like to know how the planet
> ccrma configuration works.
> 
> I have installed the planet.rpm from the core repo on Fedora 12
> (x86-64). The rt-kernel boots without errors or warnings. I can use
> qjackctl to start jackd in real-time. All-in-all a perfectly working
> system.
> 
> I noticed that etc/security/limits.conf was modified - the rtprio
> settings for jackuser and pulse-rt 

(they were not replaced, they are no longer in that file but
in /etc/security/limits.d/, I was not aware of the change when I
released my jack package). 

> were replaced with the following lines.
> 
> ## Automatically appended by the Planet CCRMA
> jack-audio-connection-kit
> * - rtprio 99
> * - memlock 4194304
> * - nice -10
> 
> How does the wildcard * work?
> 
> Does this mean that all programs multimedia and non-multimedia can run
> with rt-prio? When used by any user?

The "*" means any user can use the rt scheduler. It is not related to
applications but rather to groups of users. Fedora is more restrictive,
it requires users to be in a specific group. 

> What other settings were changed to improve rt-performance?

If you installed planetccrma-core (or planetccrma-core-PAE) you will
have the rtirq activated to run on boot. That will reorder the
priorities of irq's and other processes to optimize performance. That
should be used with Planet CCRMA's jack package which has the priority
of jackd also changed to match what rtirq does. 

> I would be grateful for any feedback to these questions, Simon

Hope this clarifies things a bit. 
-- Fernando