Mark.Haywood wrote:

> Li, Aubrey wrote:
>> Firstly, many thanks to report this bug, :-)
>> 
>> Before we setup powertop bug track system on defect.opensolaris.org,
>> can we report bug to the mailing list first?
>> 
>> my comments about this bug:
>> 
>> This is a very good raise-up, really. But I think it'd better to
>> place this bug into Todo list. Currently kernel doesn't support any
>> mechanism to obtain the frequency in the "turbo mode". So, powertop
>> can't report any related info. Actually hardware feedback machanism
>> exists on the processor, We need to enable it. 
>> 
> 
> It is true that the APERF/MPERF hardware feedback mechanism
> can help to
> identify that a processor has been in "turbo mode". But unless I'm
> mistaken there is no guarantee that when the processor is in
> Turbo Mode
> that APERF/MPERF will catch it. Among other things, it would
> depend upon
> your polling interval - which currently is pretty long.

Can't we assume the processor is in turbo mode when we are in 
P0 =  (market frequency) + 1Mhz?

> 
> What exactly would powertop report about 'turbo mode'? Amount of time
> spent in "turbo mode"? I think a metric like that is bound to be
> incorrect given the current hardware support isn't it?

If I understand correctly, the bug reporter want to know the average
frequency
in turbo mode(P0) in a sampling period, if hardware support it.

Thanks,
-Aubrey


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