Re: [PATCH v3 3/3] intel_idle: Provide enter_dead() handler for SRF

[Thomas Gleixner]

On Tue, Nov 12 2024 at 12:28, Rafael J. Wysocki wrote:
> On Tue, Nov 12, 2024 at 12:18 PM Patryk Wlazlyn
> <patryk.wlazlyn@xxxxxxxxxxxxxxx> wrote:
>> I don't think so. The old algorithm gives fairly good heuristic for computing
>> the mwait hint for the deepest cstate. Even though it's not guaranteed to work,
>> it does work on most of the platforms that don't early return. I think we should
>> leave it, but prefer idle_driver.
>
> IOW, as a fallback mechanism, it is as good as it gets.
>
> As the primary source of information though, not quite.

So we have at least 5 places in the kernel which evaluate CPUID leaf 0x5
in different ways.

Can we please have _ONE_ function which evaluates the leaf correctly
once and provides the required information for all places ready to use?

Thanks,

        tglx