notify userland about C-state changes

[Andriy Gapon]

on 03/10/2012 19:21 Sean Bruno said the following:
> On Wed, 2012-10-03 at 06:08 -0700, Andriy Gapon wrote:
>>>
>>> So quick question, does this happen a lot on a system with a
>> sporadic
>>> workload?  Does this introduce overhead to the system to service the
>>> notification requests?
>>
>> I am not sure who can answer this question.  It is up to ACPI platform
>> to decide
>> when it changes _available C-states_.  OS doesn't have control over
>> that.
>>
> Hrm ... what changes to the machine would make this happen while the
> machine is running?  things like the switching from battery to line
> power?

Yes.  Or something else [?] of similar nature/effect.

>> P.S.  I hope you haven't confused this notification for a notification
>> about
>> _current_ C-state changing. 
> 
> I did have it confused.  Thanks for putting this note in.

OK :-)

-- 
Andriy Gapon