lkml.org 
[lkml]   [2000]   [Nov]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: rdtsc to mili secs?
Pavel Machek wrote:
> >
> > Intel PIIX-based systems will do duty-cycle throttling, for example.
>
> Don't think so. My toshiba is PIIX-based, AFAIC:
>

Interesting. Some will, definitely. Didn't know that wasn't universal.

Clearly, on a machine like that, there is no hope for RDTSC, at least
unless the CPU (and OS!) gets notification that the TSC needs to be
recalibrated whenever it switches.

> 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

--
<hpa@transmeta.com> at work, <hpa@zytor.com> in private!
"Unix gives you enough rope to shoot yourself in the foot."
http://www.zytor.com/~hpa/puzzle.txt
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 12:45    [from the cache]
©2003-2011 Jasper Spaans