dpdk-test power_autotest, power_caps_autotest

[Antonio Di Bacco]

The dpdk-test is really a nice piece of software.
Today I tried to use it to "autotest" the power DPDK subsystem but I
fail to fully understand the feedback it gives (consider I've disable
intel_pstate driver):

For example:

RTE>>power_autotest
POWER: Invalid Power Management Environment(0) set


RTE>>power_caps_autotest
POWER: Env isn't set yet!
POWER: Attempting to initialise ACPI cpufreq power management...
POWER: Failed to write /sys/devices/system/cpu/cpu%u/cpufreq/scaling_governor
POWER: Cannot set governor of lcore 2 to userspace
POWER: Attempting to initialise PSTAT power management...
POWER: Initialized successfully for lcore 2 power management
POWER: Capabilities 1


How to fix the "Invalid Power Management Environment(0) set" and the
Failed to write /sys/devices/system/cpu/cpu%u/cpufreq/scaling_governor
?