On 5/22/25 3:05 AM, Shashank Balaji wrote: > The userspace governor does not have the CPUFREQ_GOV_STRICT_TARGET flag, which > means the requested frequency may not strictly be followed. This is true in the > case of the intel_pstate driver with HWP enabled. When programming the > HWP_REQUEST MSR, the min_perf is set to `scaling_setspeed`, and the max_perf > is set to the policy's max. So, the hardware is free to increase the frequency > beyond the requested frequency. > > This behaviour can be slightly surprising, given the current wording "allows > userspace to set the CPU frequency". Hence, document this. > In my opinion, the documentation is correct, and it is the implementation in intel_pstate that is wrong. If the user wanted two separate knobs that control the minimum and maximum frequencies, they could leave intel_pstate in "active" mode and change scaling_min_freq and scaling_max_freq. If the user asks for the frequency to be set from userspace, the frequency had damn well better be set from userspace. - Russell
