SCHED_ULE should not be the default

Attilio Rao attilio at
Thu Dec 15 16:25:55 UTC 2011

2011/12/9 George Mitchell <george+freebsd at>:
> dnetc is an open-source program from  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.

[Posting on the first message of the thread]

I basically went through all the e-mail you just sent and identified 4
real report on which we could work on and summarizied in the attached
Excel file.
I'd like that George, Steve, Doug, Andrey and Mike possibly review the
few datas there and add more, if they want, or make more important
clarifications in particular about the Xorg presence (or rather not)
in their workload.

I've readed a couple of message in the thread pointing the finger to
Xorg to be excessively CPU-intensive and I think they are right, we
might try to find a solution for that at some point, but it is really
a very edge case.
Geroge's and Steve's case, instead, look very different from this and
I want to analyze them in detail.
George already provided schedgraph traces and for others, if they
cannot provide them directly, I'd really appreciate they would at
least describe in detail the workload so that I get a chance to
reproduce it.

If someone else thinks he has a specific problem that is not
characterized by one of the cases above please let me know and I will
put this in the chart.

Thanks for the hard work you guys put in pointing out ULE's problem, I
think we will get at the bottom of this if we keep up sharing thoughts
and reports.


Peace can only be achieved by understanding - A. Einstein

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