On 5/6/2022 9:22 PM, Dave Hansen wrote:
> On 5/6/22 02:42, Wyes Karny wrote:
>>
>> So, if CPUID.05H:ECX[0] = 0, MWAIT extensions are not available (not allowed) and hence
>> it is safe to use MWAIT with EAX=0,ECX=0. Otherwise, we have to check CPUID.05H:EDX[bit 7:4]
>> to get the number of C1 substates and this should be greater than equal to 1.
>
> Ahh, I misread the comment. I was confusing the CPUID leaf ECX data
> with the use of ECX hints to MWAIT.
>
> Could you add maybe a sentence or two more in that comment to help
> clarify the situation?
Sure, will do. Thanks!
>