ThinkCentre A57: Throttling does not work

[herwigb]

While throttling works normally on Windows, it does not with eCS. From the acpica.log I see that it starts the powerman thread, but says a short time later that 0 of 4 CPUs are controllable.

[herwigb]

acpica.log from boot...

[herwigb]

pci.exe output for ThinkCentre A57

[herwigb]

Currently used acpid.cfg

[David Azarewicz]

In order for throttling to work it must be correctly defined in ACPI. Apparently your system's ACPI does not define throttling, so the PSD cannot know how to do it. This is not a defect in the PSD. The PSD can only do what is defined in ACPI.

[herwigb]

I see. Given the fact that I have a range of several Lenovo machines (TC A57, M57, A58, A70, TS 100) to support (none of these handles throttling properly with eCS) - is there anything I can do about that?

Do I understand correctly that the ACPI tables of these machines must be faulty/incomplete?

I started to read about ACPI tables, used iasl do decompile, even was able to fix warnings and recompile and use acpiexec to load the recompiled .aml files without complaining... not really knowing exactly what I am doing ;-)

[David Azarewicz]

Replying to herwigb:

I see. Given the fact that I have a range of several Lenovo machines (TC A57, M57, A58, A70, TS 100) to support (none of these handles throttling properly with eCS) - is there anything I can do about that?

Sorry, but no. Throttling is rarely supported anymore.

Do I understand correctly that the ACPI tables of these machines must be faulty/incomplete?

Probably not. Modern hardware uses more complex power management instead of throttling so it is possible that throttling is not even supported by the hardware. These new more complex methods (Cool'n'Quiet, PowerNow!, SpeedStep, etc) require custom CPU drivers specific to the processor installed. The user interface for these more complex power management methods may wrongly refer to it as "throttling", but it is not throttling as ACPI defines it.

[David Azarewicz]

Get the latest version (3.20.03). Run acpistat and that will tell you if throttling is supported on your system. You probably don't want throttling with this version anyway.

[herwigb]

The version of ACPI.PSD that is installed is 3.20.03
The system is operating in Symmetric mode (Mode 2)
The kernel is 14.105_SMP
The retail PSD is installed

Number of IRQs available: 24
IRQ 00 count 2817395
IRQ 01 count 7620
IRQ 08 count 7089443
IRQ 09 count 5888
IRQ 12 count 261837
IRQ 16 count 1896
IRQ 17 count 173474
IRQ 19 count 100332

========== CPU0 ==================
ACPI name [P001]
IPIGenCount = 9599343    IPICount    = 2506197   
IPIHLT      = 0          IdleCount   = 12539013   BusyCount   = 2100343   
========== CPU1 ==================
ACPI name [P002]
IPIGenCount = 449431     IPICount    = 5522865   
IPIHLT      = 0          IdleCount   = 181713     BusyCount   = 181712    
========== CPU2 ==================
ACPI name [P003]
IPIGenCount = 1148932    IPICount    = 5309061   
IPIHLT      = 0          IdleCount   = 505246     BusyCount   = 505245    
========== CPU3 ==================
ACPI name [P004]
IPIGenCount = 5906453    IPICount    = 3766036   
IPIHLT      = 0          IdleCount   = 1636542    BusyCount   = 1636541   

This system does not support CPU Performance Control via ACPI.

This system does not support CPU Throttling.

Thermal information:
  No Thermal information is available for this computer

No AC status is available for this computer

Hmmh, I think this says it all.

[David Azarewicz]

Yeah, that is pretty clear, isn't it. You would need a separate custom driver for your specific CPU to take advantage of any processor specific power management. However, the new kernel patch for idle time halt should help some. You should also enable the Power Manager so it can stop CPUs 1, 2 and 3 when they are not needed. That is about the best you can do on that system.

[herwigb]

Yes, the idle stuff seems to help. And power manager stops CPU1,2 and 3 successfully when idle. Thx for your efforts!