KAUTH_PROCESS_SCHEDULER_*AFFINITY restricted to root in default secmodel?

[Jeff Rizzo <riz%tastylime.net@localhost>]

I've just had my first occasion to play with the processor affinity 
code, via porting some code from linux.  It was very straightforward, 
but there's one glaring difference:  linux doesn't (by default, anyway) 
require root to use their sched_setaffinity(), while we do require root 
(by default) for pthread_setaffinity_np().

I don't pretend to understand the security ramifications regarding 
processor affinity;  I do wonder, however, whether it warrants requiring 
elevated privilege (and possible exposure via other code in the process 
which doesn't require root for normal operation) to prevent allowing 
users to pin their own code to a particular cpu by default.  Are we sure 
we've made the right (default) tradeoff here?

For my own use, I know I can tweak the secmodel to permit 
KAUTH_PROCESS_SCHEDULER_SETAFFINITY .  (and now I'm going to research 
how to actually do it.  :)

Thanks,
+j