Re: Help in finding the cycle counter for mips and mipsel
On Sat, May 03, 2003 at 10:12:22PM +0200, Thiemo Seufer wrote:
> Guido Guenther wrote:
> > You wrote:
> > > First, if the linux kernel can be believed, the way to access the
> > > cycle counter can be found in linux/include/asm-mips/timex.h. This is
> > I think this will cause an "Illegal instruction"
>
> "coprocessor unusable", I think.
Userspace is seeing a SIGILL. That's all I ment to say.
> > when used from user
> > mode since this uses the bfc0 instruction. I'm not sure if you can
> > access the cycle counter from user mode at all.
>
> It won't help anyway, as the counter is only avalable for R4000
> style CPUs, and used for the jiffies counter by the kernel.
Looking at the fftw3 code this looks like the kind of counter James was
looking for.
-- Guido
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