Re: rdtsc to mili secs?

[Pavel Machek <pavel@suse.cz>]

Hi!

> > > Sensibly configured power saving/speed throttle systems do not change the
> > > frequency at all. The duty cycle is changed and this controls the cpu 
> > > performance but the tsc is constant
> > 
> > Do you have an example of notebook that does powersaving like that?
> > I have 2 examples of notebooks with changing TSC speed...
> > 
> 
> Intel PIIX-based systems will do duty-cycle throttling, for example.

Don't think so. My toshiba is PIIX-based, AFAIC:

root@bug:~# cat /proc/pci
  Bus  0, device   5, function  0:
    Bridge: Intel Corporation 82371AB PIIX4 ISA (rev 2).
  Bus  0, device   5, function  1:
    IDE interface: Intel Corporation 82371AB PIIX4 IDE (rev 1).
      Master Capable.  Latency=64.
      I/O at 0x1000 [0x100f].
  Bus  0, device   5, function  2:
    USB Controller: Intel Corporation 82371AB PIIX4 USB (rev 1).
      IRQ 11.
      Master Capable.  Latency=64.
      I/O at 0xffe0 [0xffff].
  Bus  0, device   5, function  3:
    Bridge: Intel Corporation 82371AB PIIX4 ACPI (rev 2).

Still, it is willing to run with RDTSC at 300MHz, 150MHz, and
40MHz. (The last one in _extreme_ cases when CPU fan fails -- running
at 40MHz is better than cooking cpu).


-- 
I'm pavel@ucw.cz. "In my country we have almost anarchy and I don't care."
Panos Katsaloulis describing me w.r.t. patents at discuss@linmodems.org
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