Andrea Arcangeli wrote:
>
> On Fri, 3 Mar 2000, Boris Okun wrote:
>
> >I sometiems get a couple of backs if I put i=1000000
>
> that's normal. tsc goes ahead even while the irq got lost, then when the
> irq happens the tsc diff restart from zero but the xtime lost one tick.
Does this mean that my solution is correct, or you still think that I
just messed things up and thus masked the problem?
BTW, the following is from fftw site:
The configure option --enable-pentium-timer enables the use of the
Pentium and
PentiumPro cycle counter for timing purposes. In order to get correct
results, you must define FFTW_CYCLES_PER_SEC in fftw/config.h to be the
clock speed of your processor; the resulting FFTW library will be
nonportable. The use of this option is deprecated. On serious operating
systems (such as Linux), FFTW
^^^^^^^^^^^^^^^^^^
uses gettimeofday(), which has enough resolution and is portable.
Boris
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