Support cpupower

[psyhtest]

If we install linux-tools-* on Ubuntu (including in Docker):

sudo apt install linux-tools-common linux-tools-generic 

we can easily switch between different governors e.g.:

• for Peak Performance profiles:

sudo cpupower frequency-set --governor performance

• for Energy Efficiency profiles:

sudo cpupower frequency-set --governor powersave

More options can be available like conservative and ondemand, but performance and powersave should be sufficient.

We would like to add these commands to axs, so that when governor=$GOVERNOR is specified, we automatically run:

sudo cpupower frequency-set --governor $GOVERNOR

before the experiment.

[psyhtest]

Check current governor (powersave)

cpupower frequency-info

analyzing CPU 0:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency:  Cannot determine or is not supported.
  hardware limits: 1000 MHz - 4.00 GHz
  available cpufreq governors: performance powersave
  current policy: frequency should be within 1000 MHz and 4.00 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency: Unable to call hardware
  current CPU frequency: 1.11 GHz (asserted by call to kernel)
  boost state support:
    Supported: yes
    Active: yes

Set new governor (performance)

sudo cpupower frequency-set --governor performance

Setting cpu: 0
Setting cpu: 1
Setting cpu: 2
Setting cpu: 3
Setting cpu: 4
Setting cpu: 5
Setting cpu: 6
Setting cpu: 7
Setting cpu: 8
Setting cpu: 9
Setting cpu: 10
Setting cpu: 11
Setting cpu: 12
Setting cpu: 13
Setting cpu: 14
Setting cpu: 15
Setting cpu: 16
Setting cpu: 17
Setting cpu: 18
Setting cpu: 19
Setting cpu: 20
Setting cpu: 21
Setting cpu: 22
Setting cpu: 23
Setting cpu: 24
Setting cpu: 25
Setting cpu: 26
Setting cpu: 27
Setting cpu: 28
Setting cpu: 29
Setting cpu: 30
Setting cpu: 31
Setting cpu: 32
Setting cpu: 33
Setting cpu: 34
Setting cpu: 35
Setting cpu: 36
Setting cpu: 37
Setting cpu: 38
Setting cpu: 39
Setting cpu: 40
Setting cpu: 41
Setting cpu: 42
Setting cpu: 43
Setting cpu: 44
Setting cpu: 45
Setting cpu: 46
Setting cpu: 47

Check current governor (performance)

cpupower frequency-info

analyzing CPU 0:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency:  Cannot determine or is not supported.
  hardware limits: 1000 MHz - 4.00 GHz
  available cpufreq governors: performance powersave
  current policy: frequency should be within 1000 MHz and 4.00 GHz.
                  The governor "performance" may decide which speed to use
                  within this range.
  current CPU frequency: Unable to call hardware
  current CPU frequency: 2.85 GHz (asserted by call to kernel)
  boost state support:
    Supported: yes
    Active: yes

[ens-lg4]

Currently works by adding ,desired_governor=performance or ,desired_governor=powersave (or any other value supported by cpupower ). The value is first set, then independently read (as a form of feedback), and this read value gets recorded in the experiment.

We don't yet have the desired governor linked with specific SUTs, scenarios, etc.