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#1 2016-10-19 15:50:26

positronik
Member
Registered: 2016-02-08
Posts: 94

CPU frequency scaling not working with kernel 4.8.2-1

So after today's update for the kernel the frequency scaling of my cpu doesn't work.
Actually it doesn't work when the governor is set on conservative but works when set on ondemand.
Needless to say that up to today I was using conservative and it was always working.

Here's the output of lscpu and cpupower frequency-info. Maybe someone experiences the same problem.

$ lscpu 
Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                8
On-line CPU(s) list:   0-7
Thread(s) per core:    2
Core(s) per socket:    4
Socket(s):             1
NUMA node(s):          1
Vendor ID:             AuthenticAMD
CPU family:            21
Model:                 2
Model name:            AMD FX(tm)-8350 Eight-Core Processor
Stepping:              0
CPU MHz:               1400.000
CPU max MHz:           4000.0000
CPU min MHz:           1400.0000
BogoMIPS:              8030.71
Virtualization:        AMD-V
L1d cache:             16K
L1i cache:             64K
L2 cache:              2048K
L3 cache:              8192K
NUMA node0 CPU(s):     0-7
Flags:                 fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm constant_tsc rep_good nopl nonstop_tsc extd_apicid aperfmperf eagerfpu pni pclmulqdq monitor ssse3 fma cx16 sse4_1 sse4_2 popcnt aes xsave avx f16c lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs xop skinit wdt lwp fma4 tce nodeid_msr tbm topoext perfctr_core perfctr_nb cpb hw_pstate vmmcall bmi1 arat npt lbrv svm_lock nrip_save tsc_scale vmcb_clean flushbyasid decodeassists pausefilter pfthreshold


$ cpupower frequency-info
analyzing CPU 0:
  driver: acpi-cpufreq
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 4.0 us
  hardware limits: 1.40 GHz - 4.00 GHz
  available frequency steps:  4.00 GHz, 3.40 GHz, 2.80 GHz, 2.10 GHz, 1.40 GHz
  available cpufreq governors: conservative ondemand performance
  current policy: frequency should be within 1.40 GHz and 4.00 GHz.
                  The governor "conservative" may decide which speed to use
                  within this range.
  current CPU frequency: Unable to call hardware
  current CPU frequency: 1.40 GHz (asserted by call to kernel)
  boost state support:
    Supported: yes
    Active: yes

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#2 2016-10-20 16:05:20

pdc
Member
Registered: 2015-05-30
Posts: 33

Re: CPU frequency scaling not working with kernel 4.8.2-1

There's a bug report which might be related: https://bugzilla.kernel.org/show_bug.cgi?id=177161. The poster is using the  conservative governor. The title is "CPU frequencies in /proc/cpuinfo aren't dynamically updated", but it's possible that the actual frequencies aren't changing.

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#3 2016-10-21 07:35:16

florck
Member
Registered: 2014-03-09
Posts: 9

Re: CPU frequency scaling not working with kernel 4.8.2-1

I got also the same issue with powersave and performance governor settings.
I have not been able to test the ondemand, since I rollbacked to the previous kernel version.

Here is the description of my CPU :

processor       : 3
vendor_id       : GenuineIntel
cpu family      : 6
model           : 61
model name      : Intel(R) Core(TM) M-5Y51 CPU @ 1.10GHz
stepping        : 4
microcode       : 0x18
cpu MHz         : 2461.224
cache size      : 4096 KB
physical id     : 0
siblings        : 4
core id         : 1
cpu cores       : 2
apicid          : 3
initial apicid  : 3
fpu             : yes
fpu_exception   : yes
cpuid level     : 20
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm 3dnowprefetch epb intel_pt tpr_shadow vnmi flexpriority ept vpid fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid rdseed adx smap xsaveopt dtherm ida arat pln pts
bugs            :
bogomips        : 2596.46
clflush size    : 64
cache_alignment : 64
address sizes   : 39 bits physical, 48 bits virtual
power management:

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#4 2016-10-22 08:16:42

florck
Member
Registered: 2014-03-09
Posts: 9

Re: CPU frequency scaling not working with kernel 4.8.2-1

Anyway, my CPU does not allow the ondemand governor (intel_pstates).
I tested also kernel 4.8.3 and this is not working either.

If someone gets a way to have it working, this will be great.

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