Re: Where is RLIMIT_RT_CPU?

Esben Nielsen
2006-07-16T09:44:18Z

On Sun, 16 Jul 2006, Jean-Marc Valin wrote:

>> I don't think it's a problem. If the admin does not want non-root users
>> to be able to lock up the machine, just don't put them in the realtime
>> group.
>
> What if the admin *wants* non-root users to have good quality audio, and
> just doesn't want them to crash the system (voluntarily and especially
> accidentally). Enforcing CPU limits *is* possible and it has already
> been done independently by both Ingo and Con. I'm just waiting for the
> feature to be available out-of-the box, which is not for today if kernel
> space keeps pointing at userspace and vice versa. :-(
>
> Jean-Marc
>

You can't have "random" users scheduling thing at real-time priorities.
A real-time system can only work if it is set up as whole and all
real-time tasks are taken into consideration. If you allow a user to start
another real-time task, that task might destroy the real-time properties
of all the rest by taking too much cpu.

As I see it the only thing you can do is to use sudo to run anything,
which needs real-time priority, with higher priviliges, than what a normal
user have. Then he can only start specific audio programs and can't crash
the system (unless those programs have a bug).

Esben