Re: [PATCH] [18/20] x86: Don't disable TSC in any C states on AMD Fam10h

Ingo Molnar
2008-01-04T08:41:19Z

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

> The ACPI code currently disables TSC use in any C2 and C3 states. But
> the AMD Fam10h BKDG documents that the TSC will never stop in any C
> states when the CONSTANT_TSC bit is set. Make this disabling
> conditional on CONSTANT_TSC not set on AMD.
>
> I actually think this is true on Intel too for C2 states on CPUs with
> p-state invariant TSC, but this needs further discussions with Len to
> really confirm :-)
>
> So far it is only enabled on AMD.

thanks Andi - i've picked this up for x86.git, to get it tested. Len,
what do you think? If/when you pick it up into the ACPI tree i'll drop
it from x86.git.

Ingo