`intel_pstate` driver and MaxKHz parameter

[mlincett]

It seems that trying to control the maximum clockspeed through the MaxKHz parameter is somewhat ineffective on a platform that uses the intel_pstate scaling driver. An example.

Besides, the /sys/devices/system/cpu/cpufreq/policy?/scaling_available_frequencies property is not exposed by intel_pstate.

Is there a workaround to run the benchmark at a fixed max clockspeed on Intel?