non-invariant tsc and cputicker
Jung-uk Kim
jkim at FreeBSD.org
Mon Dec 6 19:11:02 UTC 2010
On Monday 06 December 2010 01:56 pm, Andriy Gapon wrote:
> on 06/12/2010 20:34 Jung-uk Kim said the following:
> > I understand that. However, it is not clear to me why you want
> > to pessimize performance of old hardware. If you can convince me
> > old hardware with slow timecounter hardware (e.g., i8254) does
> > not hurt too much, maybe it's okay.
>
> Overlooked this point - TSC can be very well used as a timecounter.
> And in that case non-invariant TSC would veto P-state changes,
> which is the proper thing to do, IMO.
Yes, thanks to njl. He made it "somewhat bogus" from "totally bogus".
I made it "almost correct" from "somewhat bogus" for modern P-state
invariant CPUs. ;-)
Jung-uk Kim
More information about the freebsd-current
mailing list