Re: BogoMIPS
Michal Jaegermann (michal@ellpspace.math.ualberta.ca)
Tue, 6 Oct 1998 21:25:55 -0600 (MDT)
Harald Koenig wrote:
.....
> > > I presume this is a joke.
> >
> > Sorry, it is not. Someone shown timings of empty loop at they were
> > dependend on placement of code in page. (It gives plenty of sense if
> > code happens to cross page boundary.)
>
> correct. at least my Intel PODP83 shows this weird behaviour when the loop
> is just before a page boundary and IIRC there have been some reports of
> other CPUs showing similar effects.
This is a rather small loop. Maybe it would be enough to align it
on the next power of 2 not bigger than a code size? That would ensure
that one is not cycling across a page boundary.
--mj
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