cvs commit: src/sys/conf options.i386 src/sys/i386/i386 tsc.c src/sys/i386/conf NOTES

[Dag-Erling Smorgrav]

"Poul-Henning Kamp" <phk at phk.freebsd.dk> writes:
> In message <xzpof3js45j.fsf at flood.ping.uio.no>, Dag-Erling Smorgrav writes:
> >                                              On most SMP systems, the
> > PIIX timecounter is automatically selected by virtue of being
> > discovered last.
> It is specifically discovered last because it should be used if
> at all possible.

It's more precise than the TSC (mostly because the TSC calibration
code sucks), but if one is willing to sacrifice a small amount of
precision for performance, then the TSC is probably better, I think.

> There is a big difference if you get to use "ACPI-fast" (correctly
> implemented hardware) instead of "ACPI-safe" (buggy hardware).

Unfortunately, ACPI-fast is not available on my system.

DES
-- 
Dag-Erling Smorgrav - des at ofug.org