Re: Performance overhead of get_cycles_sync

Ingo Molnar
2007-12-11T20:19:55Z

* Andi Kleen <ak@suse.de> wrote:

> Ingo Molnar <mingo-X9Un+BFzKDI@public.gmane.org> writes:
>
> > the TSC clocksource (and hence the vsyscall code) is turned off on
> > systems that fail the TOD/CLOCK portion of this test:
>
> Which is not on core2 which was the question about. And if it was
> turned off it wouldn't use get_cycles_sync() at all.

it is turned off on core2 too:

# cat /sys/devices/system/clocksource/clocksource0/current_clocksource
acpi_pm

Ingo