v4.8 cpufreq regression?

From: Aaro Koskinen
Date: Fri Oct 07 2016 - 18:59:55 EST


Hi,

I'm upgrading from v4.7 to v4.8 on MIPS/loongson2_cpufreq with
cpufreq/ondemand and I noticed that /proc/cpuinfo is always reporting
(regardless of system load):

BogoMIPS : 697150.20

and sysfs:

/sys/devices/system/cpu/cpufreq/policy0/affected_cpus:0
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_cur_freq:797800
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_max_freq:797800
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_min_freq:199450
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_transition_latency:0
/sys/devices/system/cpu/cpufreq/policy0/related_cpus:0
/sys/devices/system/cpu/cpufreq/policy0/scaling_available_frequencies:199450 299175 398900 498625 598350 698075 797800
/sys/devices/system/cpu/cpufreq/policy0/scaling_available_governors:ondemand performance
/sys/devices/system/cpu/cpufreq/policy0/scaling_cur_freq:797800
/sys/devices/system/cpu/cpufreq/policy0/scaling_driver:loongson2
/sys/devices/system/cpu/cpufreq/policy0/scaling_governor:ondemand
/sys/devices/system/cpu/cpufreq/policy0/scaling_max_freq:797800
/sys/devices/system/cpu/cpufreq/policy0/scaling_min_freq:199450
/sys/devices/system/cpu/cpufreq/policy0/scaling_setspeed:<unsupported>

although previously they reported (when idle):

BogoMIPS : 132.09

/sys/devices/system/cpu/cpufreq/policy0/affected_cpus:0
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_cur_freq:199445
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_max_freq:797780
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_min_freq:199445
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_transition_latency:0
/sys/devices/system/cpu/cpufreq/policy0/related_cpus:0
/sys/devices/system/cpu/cpufreq/policy0/scaling_available_frequencies:199445 299167 398890 498612 598335 698057 797780
/sys/devices/system/cpu/cpufreq/policy0/scaling_available_governors:ondemand performance
/sys/devices/system/cpu/cpufreq/policy0/scaling_cur_freq:199445
/sys/devices/system/cpu/cpufreq/policy0/scaling_driver:loongson2
/sys/devices/system/cpu/cpufreq/policy0/scaling_governor:ondemand
/sys/devices/system/cpu/cpufreq/policy0/scaling_max_freq:797780
/sys/devices/system/cpu/cpufreq/policy0/scaling_min_freq:199445
/sys/devices/system/cpu/cpufreq/policy0/scaling_setspeed:<unsupported>

and under full load:

BogoMIPS : 528.38

/sys/devices/system/cpu/cpufreq/policy0/affected_cpus:0
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_cur_freq:797780
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_max_freq:797780
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_min_freq:199445
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_transition_latency:0
/sys/devices/system/cpu/cpufreq/policy0/related_cpus:0
/sys/devices/system/cpu/cpufreq/policy0/scaling_available_frequencies:199445 299167 398890 498612 598335 698057 797780
/sys/devices/system/cpu/cpufreq/policy0/scaling_available_governors:ondemand performance
/sys/devices/system/cpu/cpufreq/policy0/scaling_cur_freq:797780
/sys/devices/system/cpu/cpufreq/policy0/scaling_driver:loongson2
/sys/devices/system/cpu/cpufreq/policy0/scaling_governor:ondemand
/sys/devices/system/cpu/cpufreq/policy0/scaling_max_freq:797780
/sys/devices/system/cpu/cpufreq/policy0/scaling_min_freq:199445
/sys/devices/system/cpu/cpufreq/policy0/scaling_setspeed:<unsupported>

The offeding commit (bisected) seems to be:

commit da0c6dc00c69d0adaae99c3b3d2ea0c869a3fb35
Author: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
Date: Mon Jun 27 16:04:07 2016 +0530

cpufreq: Handle sorted frequency tables more efficiently

Any ideas?

A.