SCHED_ULE should not be the default

Volodymyr Kostyrko c.kworr at gmail.com
Fri Dec 9 15:07:34 UTC 2011


09.12.2011 13:03, George Mitchell wrote:
> dnetc is an open-source program from http://www.distributed.net/. It
> tries a brute-force approach to cracking RC4 puzzles and also computes
> optimal Golomb rulers. It starts up one process per CPU and runs at
> nice 20 and is, for all intents and purposes, 100% compute bound.

nice 20 doesn't mean it should give time to just any other program. Have 
you tried setting dnetc_idprio?

> Not everybody runs this sort of program, but there are plenty of
> similar projects out there, and people who try to participate in
> them will be mightily displeased with their FreeBSD systems when
> they do. Is there some case where SCHED_ULE exhibits significantly
> better performance than SCHED_4BSD? If not, I think SCHED-4BSD
> should remain the default GENERIC configuration until this is fixed.

Not fully right, boinc defaults to run on idprio 31 so this isn't an 
issue. And yes, there are cases where SCHED_ULE shows much better 
performance then SCHED_4BSD. You incidentally found rare misbehavior of 
SCHED_ULE and I think this would be treated.

-- 
Sphinx of black quartz judge my vow.



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