Weird "nice" behavior

[Matthias Buelow]

Lowell Gilbert <freebsd-questions-local at be-well.ilk.org> writes:

>> FreeBSD 5.4-RELEASE
>> 
>> I'm trying to do a large local rsync in the background, while listening to
>> streaming audio via RealPlayer and do other stuff. I have the rsync
>> running at nice level 20 ("nice -20") which I've confirmed via ps:

Please try: http://www.chesapeake.net/~jroberson/flushbuf.diff
before this discussion degenerates into the usual handwaving.

The patch seems to fix some awful performance issue with certain disk
i/o loads in 5.4. I don't know whether it's included in 5.4-stable by
now.

mkb.