Re: [RFD] Add debugfs for cpuidle ?

[Ulf Hansson]

On 24 May 2018 at 10:47, Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> wrote:
> On 24/05/2018 10:28, Rafael J. Wysocki wrote:
>> On Thursday, May 24, 2018 10:14:31 AM CEST Daniel Lezcano wrote:
>>>
>>> Hi all,
>>
>> Hi,
>>
>>> would it be interesting to add debugfs metrics for cpuidle in order
>>> to read some statistics from there and investigate the behavior ?
>>
>> What exactly would you like to see in there?
>
> It could be interesting to have statistics on a per cpu and global basis
> for:
>
> - prediction accuracy:
>
> /sys/kernel/debug/cpuidle/prediction/[good|over|under]
> /sys/kernel/debug/cpuidle/cpu*/state*/prediction/[good|over|under]
>
>  - exit latency
>
> In addition, it is often the case the idle states values are dropped
> randomly, it is interesting to see the average exit latency for the
> states. That could give also an indication the cluster idle state success.
>
> /sys/kernel/debug/cpuidle/state*/latency/[min|max|avg|stddev]
> /sys/kernel/debug/cpuidle/cpu*/state*/prediction/[min|max|avg|stddev]
>
> And perhaps more information like the tick stopped stat ?
>

Daniel,

Any chance that you have some draft version of actual code implementing this?

I would be very interested to try then - or help out to implement
this, in case you haven't started yet.

Kind regards
Uffe