Re: [v3.10-rc] intel_pstate question

From: Dirk Brandewie
Date: Tue May 28 2013 - 11:52:55 EST


Hi JÃrg,

On 05/28/2013 08:02 AM, JÃrg Otte wrote:
Hi,

the sysfs-interface of intel_pstate is different to that of the acpi driver:
- intel_pstate shows current cpu-frequency in "cpuinfo_cur_freq" whereas
the acpi counterpart uses "scaling_cur_freq".
- moreover cpuinfo_cur_freq is readable by root only, whereas
scaling_cur_freq is world readable.

A monitoring tool must take care of theese differences.
Is this intentional?


This is a side effect of the interface that intel_pstate presents to the cpufreq
core.

cpuinfo_cur_freq reports the value returned from the scaling driver.

scaling_cur_freq reports the current frequency in the governors policy structure.

intel_pstate has an internal governor so the core does not try to interpret
the policy structure.

I don't know why cpuinfo_cur_info is read-only root maybe Rafael knows the history.


Thanks, JÃrg

Please CC me in answeres, I'm not subscribed.


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