Hi Dirk,
I don't get why you remove the c0 tracking. This is my understanding wrong.
Suppose it is removed, then the objective of the PID control is:
delta(aperf) / delta(mperf) * max_pstate / current_pstate
But delta(aperf) / delta(mperf) * max_pstate is the average frequency of the
last
time frame, and current_pstate is the last requested frequency, then the
objective is:
last_freq_average / last_requested_freq ==> setpoint
What does it mean, SW satisfaction of freq request? Why control that?
Thanks
Yuyang
> @@ -561,46 +559,37 @@ static inline void intel_pstate_calc_busy(struct
> cpudata *cpu,
> struct sample *sample)
> {
> int32_t core_pct;
> - int32_t c0_pct;
>
> core_pct = div_fp(int_tofp((sample->aperf)),
> int_tofp((sample->mperf)));
> core_pct = mul_fp(core_pct, int_tofp(100));
> FP_ROUNDUP(core_pct);
>
> - c0_pct = div_fp(int_tofp(sample->mperf), int_tofp(sample->tsc));
> -
> sample->freq = fp_toint(
> mul_fp(int_tofp(cpu->pstate.max_pstate * 1000), core_pct));
>
> - sample->core_pct_busy = mul_fp(core_pct, c0_pct);
> + sample->core_pct_busy = core_pct;
> }
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
