diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index ff58029a56e2..8bfebaeda2dd 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -143,6 +143,7 @@ struct cpu_defaults { }; static inline int32_t get_target_pstate_use_performance(struct cpudata *cpu); +static inline int32_t get_target_pstate_use_cpu_load(struct cpudata *cpu); static struct pstate_adjust_policy pid_params; static struct pstate_funcs pstate_funcs; @@ -763,7 +764,7 @@ static struct cpu_defaults silvermont_params = { .set = atom_set_pstate, .get_scaling = silvermont_get_scaling, .get_vid = atom_get_vid, - .get_target_pstate = get_target_pstate_use_performance, + .get_target_pstate = get_target_pstate_use_cpu_load, }, }; @@ -784,7 +785,7 @@ static struct cpu_defaults airmont_params = { .set = atom_set_pstate, .get_scaling = airmont_get_scaling, .get_vid = atom_get_vid, - .get_target_pstate = get_target_pstate_use_performance, + .get_target_pstate = get_target_pstate_use_cpu_load, }, }; @@ -890,12 +891,11 @@ static inline void intel_pstate_sample(struct cpudata *cpu) local_irq_save(flags); rdmsrl(MSR_IA32_APERF, aperf); rdmsrl(MSR_IA32_MPERF, mperf); - if (cpu->prev_mperf == mperf) { + tsc = rdtsc(); + if ((cpu->prev_mperf == mperf) || (cpu->prev_tsc == tsc)) { local_irq_restore(flags); return; } - - tsc = rdtsc(); local_irq_restore(flags); cpu->last_sample_time = cpu->sample.time; @@ -930,6 +930,25 @@ static inline void intel_pstate_set_sample_time(struct cpudata *cpu) mod_timer_pinned(&cpu->timer, jiffies + delay); } +static inline int32_t get_target_pstate_use_cpu_load(struct cpudata *cpu) +{ + struct sample *sample = &cpu->sample; + int32_t cpu_load; + + /* + * The load can be estimated as the ratio of the mperf counter + * running at a constant frequency during active periods + * (C0) and the time stamp counter running at the same frequency + * also during C-states. + */ + cpu_load = div64_u64(int_tofp(100) * sample->mperf, sample->tsc); + + cpu->sample.busy_scaled = cpu_load; + + return cpu->pstate.current_pstate - pid_calc(&cpu->pid, cpu_load); +} + + static inline int32_t get_target_pstate_use_performance(struct cpudata *cpu) { int32_t core_busy, max_pstate, current_pstate, sample_ratio;