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SubjectRe: Interesting scheduling times - NOT
On Tue, 22 Sep 1998, Larry McVoy wrote:

> How many times before it sinks in: 77% variance is not cache induced. If
> that were true, then nothing would be deterministic. You wouldn't be able
> to say "time make" and expect to get anything like the same number two times
> in a row, yet people do that all the time.

This is not really true, especially for something like make. If you
combine n events of average length t and std dev u, you get an event of
average length n*t, but a smaller std dev - if you multiply a bunch of
bell curves together, you get a tighter curve. The possible range becomes
larger, sure.

Not that you would really expect most of events you'd benchmark on a
computer to have a very bell-shaped distribution.

--
"Love the dolphins," she advised him. "Write by W.A.S.T.E.."

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