Hi Rafael, 2016-08-01 7:38 GMT+08:00 Rafael J. Wysocki <[email protected]>: > From: Rafael J. Wysocki <[email protected]> > > The PID-base P-state selection algorithm used by intel_pstate for > Core processors is based on very weak foundations. Namely, its > decisions are mostly based on the values of the APERF and MPERF > feedback registers and it only estimates the actual utilization to > check if it is not extremely low (in order to avoid getting stuck > in the highest P-state in that case). > > Since it generally causes the CPU P-state to ramp up quickly, it > leads to satisfactory performance, but the metric used by it is only > really valid when the CPU changes P-states by itself (ie. in the turbo > range) and if the P-state value set by the driver is treated by the > CPU as the upper limit on turbo P-states selected by it.
Do you mean CPU will ignore the request value which is submitted by intel_pstate driver in the turbo range, but respect the upper limit on the turbo P-states which is submitted by intel_pstate driver? Regards, Wanpeng Li
