Re: 4.8.1 regression with cpufreq governors

From: Tim Walberg
Date: Wed Oct 19 2016 - 16:06:19 EST


This indeed turned out to be the fix.

On 10/18/2016 23:10 +0200, Rafael J. Wysocki wrote:
>> On Monday, October 17, 2016 07:46:06 PM Tim Walberg wrote:
>> > May or may not be related to similar reports, but here's what I've just observed
>> > on my system. Built a stock kernel from tags/v4.8.1, relevant cpufreq bits:
>> >
>> > CONFIG_ACPI_CPU_FREQ_PSS=y
>> > CONFIG_CPU_FREQ=y
>> > CONFIG_CPU_FREQ_GOV_ATTR_SET=y
>> > CONFIG_CPU_FREQ_GOV_COMMON=y
>> > CONFIG_CPU_FREQ_STAT=y
>> > CONFIG_CPU_FREQ_STAT_DETAILS=y
>> > # CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE is not set
>> > # CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE is not set
>> > # CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE is not set
>> > # CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND is not set
>> > CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE=y
>> > # CONFIG_CPU_FREQ_DEFAULT_GOV_SCHEDUTIL is not set
>> > CONFIG_CPU_FREQ_GOV_PERFORMANCE=y
>> > CONFIG_CPU_FREQ_GOV_POWERSAVE=m
>> > CONFIG_CPU_FREQ_GOV_USERSPACE=m
>> > CONFIG_CPU_FREQ_GOV_ONDEMAND=m
>> > CONFIG_CPU_FREQ_GOV_CONSERVATIVE=y
>> > CONFIG_CPU_FREQ_GOV_SCHEDUTIL=m
>> > # CONFIG_X86_PCC_CPUFREQ is not set
>> > CONFIG_X86_ACPI_CPUFREQ=m
>> > CONFIG_X86_ACPI_CPUFREQ_CPB=y
>> >
>> >
>> > Conservative is set as default governer, yet when boot completes, all CPUs are
>> > pegged at the highest frequency. Changing governor to powersave knocks them all
>> > down to the lowest available frequency. Putting them back on conservative (or
>> > ondemand) results in no change in frequency, despite generating load. Switching
>> > to performance of course kicks them back up to high frequency. Basically, the
>> > governors don't seem to be ... governing.
>>
>> The "convervative" governor issue seems to be the one fixed recently
>> (http://git.kernel.org/cgit/linux/kernel/git/rafael/linux-pm.git/commit/?h=pm-cpufreq&id=abb6627910a1e783c8e034b35b7c80e5e7f98f41).
>>
>> I'm not sure why "ondemand" behaves incorrectly for you though.
>>
>> Thanks,
>> Rafael
End of included message



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