Re: Dual core Athlons and unsynced TSCs

Andi Kleen
2006-01-16T01:19:40Z

john stultz <johnstul@us.ibm.com> writes:
>
> With 2.6.15 on x86-64:
> If available, alternate timesources (HPET, ACPI PM) will be used if
> available on AMD SMP systems. (clock= is i386 only)

It would be good if it worked on x86-64 too - simply to unconfuse people.
It's somewhere on my todo list, but patches welcome.

> With 2.6.15 on i386:
> If CONFIG_X86_PM_TIMER is enabled, and available it is the preferred
> clocksource over the TSC. Some distros have changed this priority
> causing the TSC to be preferred. In these cases clock=pmtmr is needed.

One problem is that it is not obvious enough to people that
CONFIG_X86_PM_TIMER is really needed for correct timing on many system
and they just don't enable it. That is why we got so many bogus reports.

I just changed it on x86-64 to be dependent on EMBEDDED, on by
default. i386 probably should do this change too.

-Andi