Add CPUID subleaf capability to cpuctl/cpucontrol

[Jia-Shiun Li]

On Thu, Mar 27, 2014 at 8:38 PM, Konstantin Belousov
<kostikbel at gmail.com> wrote:
>
> From what I remember, in the multi-socket configuration Intel allows
> CPUs to only differ by stepping. Due to this, I see only one possible
> uses of executing CPUID on specific core, to get the stepping of the
> package, to either test for the presence of the specific CPU bug, or to
> select the proper microcode update.
>
> That said, I am curious why do you want this feature.

I'd like to do some CPU monitoring w/ MSR, thus need to identify CPU
topology & CPU id on specific logical ones. I am sure there are some
info from kernel, sysctl, etc. Even utilities readily available. But I
am just curious on how it works anyway. With topology and MSR access
via cpuctl, it should be able to do some monitoring from user space.

After a quick scan, I think the most similar in ports should be i7z.

Jia-Shiun.