Re: How is user space notified of CPU speed changes?

[Chris Friesen]

Lee Revell wrote:
> On Fri, 2004-10-22 at 13:40 -0600, Chris Friesen wrote:
> > x86 really could use an on-die register that increments at 1GHz independent of 
> > clock speed and is synchronized across all CPUs in an SMP box.
>
>
> Like this? (posted to jackit-devel):
>
> On Fri, 2004-10-22 at 18:20 -0500, Jack O'Quin wrote: 
> > On PowerPC, JACK uses the lower half of the 64-bit Timebase register,
> > which is accessible from user mode.  This is better then the i386
> > cycle counter, I believe.

Yes, ppc tbr is nice.  It's actually lower resolution than the x86 one, but it 
might be better for smp and freq changes--not sure.

Chris
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/