Re: [PATCH] [request for inclusion] Realtime LSM

Nick Piggin
2005-01-14T04:04:43Z

On Fri, 2005-01-14 at 14:38 +1100, Con Kolivas wrote:
> Paul Davis wrote:

> > its a fine answer, but its the answer to a slightly different
> > question. if anyone (maybe us audio freaks, maybe someone else) comes
> > up with a reason to want "The Real SCHED_FIFO", the original question
> > will have gone unanswered.
>
> Ah then you missed something. You can set the max cpu of SCHED_ISO to
> 100% and then you have it.
>

Is that a good solution? I'm not sure if it is wise to try to
masquerade SCHED_ISO as an unprivileged RT class.

I mean what happens if two users are trying to run independent
SCHED_ISO systems? Both will probably break, right?

And how can you provide _any_ guarantees in an arbitrary environment
without this becoming a privileged operation? I can't quite get my head
around that at the moment...

I guess if you have SCHED_ISO start out with 0 guarantees, and have root
dole some out, then it may be workable. But then that is just another
specialised ad hoc sort of hack wouldn't it? (not talking about
SCHED_ISO itself, but the granting of the privilege to use it).