Implement THREAD_PRIORITY_TIME_CRITICAL

[Mike Hearn]

On Fri, 31 Mar 2006 16:47:48 -0500, Chris Morgan wrote:
> Can't we use kernel capabilities to let people do this without having
> to run as root?  Thats what jack audio server users are advised to do
> to ensure SCHED_FIFO.

Could be - there are lots of options for doing this without root access.
Apart from the warning which is easy to delete, this patch doesn't require
root. It just tries to set the scheduler, and prints a simple tip if it
fails. So, whatever schemes are used, this patch is still needed.