idprio safe?

[Christian Weisgerber]

Is it safe nowadays to run a process at idle priority?  Or is there
still the danger of priority inversion / a deadlock?

On FreeBSD 4.x you can run a process, such as setiathome, at nice
level 19 and it will (almost) only ever get CPU time when no process
of normal priority competes with it.  FreeBSD 5.x is much "fairer"
in this respect, which has the unpleasant result that such a
background process will noticeably compete for CPU now.

-- 
Christian "naddy" Weisgerber                          naddy at mips.inka.de