* Re: [Powertop] regarding cpuidle stats
@ 2013-07-29 13:34 Arjan van de Ven
0 siblings, 0 replies; 3+ messages in thread
From: Arjan van de Ven @ 2013-07-29 13:34 UTC (permalink / raw)
To: powertop
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On 7/29/2013 6:09 AM, Arjan van de Ven wrote:
> On 7/29/2013 3:52 AM, remu kelly wrote:
>> Hi powertop team,
>> I have few questions about powertop as below:-
>> 1) Does powertop use "<debugfs>/cpuidle/stats" for retriving the C state information.
>
> no
>
> it uses various kernel trace points to collect things as they happen
I should mention that we also use hardware counters on systems that have them;
much more accurate than any OS counter ;)
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [Powertop] regarding cpuidle stats
@ 2013-07-29 13:09 Arjan van de Ven
0 siblings, 0 replies; 3+ messages in thread
From: Arjan van de Ven @ 2013-07-29 13:09 UTC (permalink / raw)
To: powertop
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On 7/29/2013 3:52 AM, remu kelly wrote:
> Hi powertop team,
> I have few questions about powertop as below:-
> 1) Does powertop use "<debugfs>/cpuidle/stats" for retriving the C state information.
no
it uses various kernel trace points to collect things as they happen
> 2) Is it possible that on "cat <debugfs>/cpuidle/stats" , we see the C3 state is having '0' count. but at same time powertop show the C3 state being hit?
I am not sure how well cpuidle stats work; never used them.
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Powertop] regarding cpuidle stats
@ 2013-07-29 10:52 remu kelly
0 siblings, 0 replies; 3+ messages in thread
From: remu kelly @ 2013-07-29 10:52 UTC (permalink / raw)
To: powertop
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Hi powertop team,
I have few questions about powertop as below:-
1) Does powertop use "<debugfs>/cpuidle/stats" for retriving the C state
information.
2) Is it possible that on "cat <debugfs>/cpuidle/stats" , we see the C3
state is having '0' count. but at same time powertop show the C3 state
being hit?
Regards,
remu
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^ permalink raw reply [flat|nested] 3+ messages in thread
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