Messages in this thread | | | Subject | Re: [PATCH 0/4] CPUFreq statistics retrieved by drivers | From | Lukasz Luba <> | Date | Wed, 5 Aug 2020 12:04:42 +0100 |
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On 8/4/20 6:27 PM, Florian Fainelli wrote: > > > On 7/29/2020 8:12 AM, Lukasz Luba wrote: >> Hi all, >> >> The existing CPUFreq framework does not tracks the statistics when the >> 'fast switch' is used or when firmware changes the frequency independently >> due to e.g. thermal reasons. However, the firmware might track the frequency >> changes and expose this to the kernel. > > Or the firmware might have changed the CPU frequency in response to a > request from the secure world for instance.
Possible
> >> >> This patch set aims to introduce CPUfreq statistics gathered by firmware >> and retrieved by CPUFreq driver. It would require a new API functions >> in the CPUFreq, which allows to poke drivers to get these stats. > > From a debugging perspective, it would be helpful if the firmware > maintained statistics were exposed as a super-set of the Linux cpufreq > statistics and aggregated into them such that you could view the normal > world vs. secure world residency of a given frequency point. This would > help because a lot of times, Linux requests freq X, but the secure world > requires freq Y (with X >= Y) and people do not really understand why > the resulting power usage is higher for instance. > > What are your thoughts on this? >
I know that Viresh is going to develop patches and improve these cpufreq stats framework. Maybe he also had this 'aggregation' in mind. I will leave it him.
Thank you for your feedback.
Regards, Lukasz
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