cvs commit: src/sys/conf options.i386 src/sys/i386/i386 tsc.c
phk at phk.freebsd.dk
Sun Apr 6 15:04:04 PDT 2003
In message <xzpof3js45j.fsf at flood.ping.uio.no>, Dag-Erling Smorgrav writes:
>Nate Lawson <nate at root.org> writes:
>> Perhaps you could enable this option by default if it had a corresponding
>> check for drift that would disable it if things got out of hand.
>There wouldn't be much point in that unless the SMP_TSC option also
>forced the TSC to be selected at boot time. On most SMP systems, the
>PIIX timecounter is automatically selected by virtue of being
It is specifically discovered last because it should be used if
at all possible.
>I must have bad benchmark karma, BTW - I can see no reduction of
>context switch time or any other significant performance boost when
>using the TSC on my dual Celeron system.
There is a big difference if you get to use "ACPI-fast" (correctly
implemented hardware) instead of "ACPI-safe" (buggy hardware).
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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