rr_interval experiments

From: Con Kolivas
Date: Thu Apr 19 2007 - 21:12:28 EST


On Friday 20 April 2007 01:01, Con Kolivas wrote:
> This then allows the maximum rr_interval to be as large as 5000
> milliseconds.

Just for fun, on a core2duo make allnoconfig make -j8 here are the build time
differences (on a 1000HZ config) machine:

16ms:
53.68user 4.81system 0:34.27elapsed 170%CPU (0avgtext+0avgdata 0maxresident)k

1ms:
56.73user 4.83system 0:36.03elapsed 170%CPU (0avgtext+0avgdata 0maxresident)k

5000ms:
52.88user 4.77system 0:32.37elapsed 178%CPU (0avgtext+0avgdata 0maxresident)k

For the record, 16ms is what SD v0.43 would choose as the default value on
this hardware. A load with a much lower natural context switching rate than a
kernel compile, as you said Nick, would show even greater discrepancy in
these results.

Fun eh? Note these are not for any comparison with anything else; just to show
the effect rr_interval changes have on throughput.

--
-ck
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