Messages in this thread | | | Date | Wed, 29 May 2013 11:25:10 +0200 | Subject | Re: [v3.10-rc] intel_pstate question | From | Jörg Otte <> |
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2013/5/28 Dirk Brandewie <dirk.brandewie@gmail.com>: > Hi Jörg, > > > On 05/28/2013 08:02 AM, Jörg 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. > Thank you Dirk, for the information!
Just another question: Now that processor 3a is supported, I am giving pstate driver a try on my notebook. This is the first time I see frequencies between above 2.5 and up to 3.1 GHz. With cpufreq driver I never saw that frequencies. So I think pstate driver uses turbo mode if appropriate (in contrast to cpufreq). is this correct?
Thanks, Jörg -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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