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Re: 2% speedup with Duff's device

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Nicholas Clark
January 23, 2001 09:13
Re: 2% speedup with Duff's device
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On Tue, Jan 23, 2001 at 05:08:28PM +0000, Nick Ing-Simmons wrote:
> Nicholas Clark <> writes:
> >
> >real    2m16.388s
> >user    1m3.610s
> >sys     0m11.000s
> >
> > 
> >(which is from time ./perl TEST)
> >
> >I was under the impression that real is wallclock, and the other two
> >are user and system call CPU time, not elapsed time.
> Of course. And the wall clock time is known useless.
> But if you get consistent user/sys times running the same perl
> on the same suite then you are lucky.
> I seem to get at least ±5% without changing ANYTHING apart from typing 
> !!<cr>
> at the prompt. 

This is the sort of variation I was seeing some of the time.
However, today the times for the 2 inline cases seems reasonably

Maybe as part of a test harness suite it would be useful it had
"run the test n times" and could show the average (and the variation)
to give a better estimate.

Nicholas Clark

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