On Ubuntu, scaling_governor becomes powersave after rebooted, even we configured cpufrequtils. This is because ondemand.service, it unconditionally change scaling_governor to ondemand or powersave. cpufrequtils will start before ondemand.service, scaling_governor overwrite by ondemand.service. To configure scaling_governor correctly, we have to disable this service. Fixes #9324 Closes #9325