According to POSIX, nice() has no effect for FIFO or round-robin
scheduling, and the effect is implementation-defined for other scheduling
algorithms.

Our version of nice() calls getpriority() and setpriority(), which both
return 0 and do nothing else.

According to POSIX, nice() is supposed to return the new nice value - NZERO, but our version always returns 0. I think 
this is correct because nice() isn't actually making the caller any more (or less) nice. Is this a valid interpretation?


There's a PR (# 10714) about changing the behaviour of nice(), but if we already comply to POSIX, I imagine we should 
mark this PR as "no intent to fix" and update our docs to say that nice() has no effect.

Any thoughts on this? Thanks.