ULE vs. 4BSD in RELENG_7

Josh Carroll josh.carroll at gmail.com
Thu Oct 18 09:10:57 PDT 2007

> I have noticed some performance discrepancies with ULE and 4BSD in
> RELENG_7, specifically with ffmpeg. I have all the kernel debugging
> options disabled, and as I understand it, the userland debugging is
> all off by default in RELENG_7.

Here are a couple of additional benchmarks comparing the schedulers on
my system:

make -j8 -DNOCLEAN buildkernel
4BSD: 3:25.56
ULE: 3:39.20
Difference: -6.6 %

ubench (CPU):
4BSD: 1705258
ULE: 1713510
Difference: +0.48 %

super-smack (select-key 10 10000):
4BSD: 55044.38
ULE: 68085.21
Difference: +23.69 %

super-smack (update-select 10 10000):
4BSD: 16734.15
ULE: 17631.43
Difference: +5.36 %

So at least for the MySQL super-smack benchmark (I know it's a rather
contrived benchmark), ULE is significantly faster for select-key and a
decent improvement for update-select. ubench is about the same, but
building a kernel is also slower with ULE.

Was ULE tuned with MySQL in mind, without considering other workloads?
Are there other benchmarks for "real" workloads I can run to compare
(e.g. Apache benchmarks, etc)? I'd like to help in any way I can, so
folks can choose the right scheduler for their usage model.


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