diff options
Diffstat (limited to 'drivers/cpufreq/intel_pstate.c')
| -rw-r--r-- | drivers/cpufreq/intel_pstate.c | 106 |
1 files changed, 66 insertions, 40 deletions
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index be9eade147f2..f535f8123258 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -181,6 +181,8 @@ struct _pid { * @cpu: CPU number for this instance data * @update_util: CPUFreq utility callback information * @update_util_set: CPUFreq utility callback is set + * @iowait_boost: iowait-related boost fraction + * @last_update: Time of the last update. * @pstate: Stores P state limits for this CPU * @vid: Stores VID limits for this CPU * @pid: Stores PID parameters for this CPU @@ -206,6 +208,7 @@ struct cpudata { struct vid_data vid; struct _pid pid; + u64 last_update; u64 last_sample_time; u64 prev_aperf; u64 prev_mperf; @@ -216,12 +219,13 @@ struct cpudata { struct acpi_processor_performance acpi_perf_data; bool valid_pss_table; #endif + unsigned int iowait_boost; }; static struct cpudata **all_cpu_data; /** - * struct pid_adjust_policy - Stores static PID configuration data + * struct pstate_adjust_policy - Stores static PID configuration data * @sample_rate_ms: PID calculation sample rate in ms * @sample_rate_ns: Sample rate calculation in ns * @deadband: PID deadband @@ -229,6 +233,7 @@ static struct cpudata **all_cpu_data; * @p_gain_pct: PID proportional gain * @i_gain_pct: PID integral gain * @d_gain_pct: PID derivative gain + * @boost_iowait: Whether or not to use iowait boosting. * * Stores per CPU model static PID configuration data. */ @@ -240,6 +245,7 @@ struct pstate_adjust_policy { int p_gain_pct; int d_gain_pct; int i_gain_pct; + bool boost_iowait; }; /** @@ -556,12 +562,12 @@ static void intel_pstate_hwp_set(const struct cpumask *cpumask) int min, hw_min, max, hw_max, cpu, range, adj_range; u64 value, cap; - rdmsrl(MSR_HWP_CAPABILITIES, cap); - hw_min = HWP_LOWEST_PERF(cap); - hw_max = HWP_HIGHEST_PERF(cap); - range = hw_max - hw_min; - for_each_cpu(cpu, cpumask) { + rdmsrl_on_cpu(cpu, MSR_HWP_CAPABILITIES, &cap); + hw_min = HWP_LOWEST_PERF(cap); + hw_max = HWP_HIGHEST_PERF(cap); + range = hw_max - hw_min; + rdmsrl_on_cpu(cpu, MSR_HWP_REQUEST, &value); adj_range = limits->min_perf_pct * range / 100; min = hw_min + adj_range; @@ -1029,7 +1035,7 @@ static struct cpu_defaults core_params = { }, }; -static struct cpu_defaults silvermont_params = { +static const struct cpu_defaults silvermont_params = { .pid_policy = { .sample_rate_ms = 10, .deadband = 0, @@ -1037,6 +1043,7 @@ static struct cpu_defaults silvermont_params = { .p_gain_pct = 14, .d_gain_pct = 0, .i_gain_pct = 4, + .boost_iowait = true, }, .funcs = { .get_max = atom_get_max_pstate, @@ -1050,7 +1057,7 @@ static struct cpu_defaults silvermont_params = { }, }; -static struct cpu_defaults airmont_params = { +static const struct cpu_defaults airmont_params = { .pid_policy = { .sample_rate_ms = 10, .deadband = 0, @@ -1058,6 +1065,7 @@ static struct cpu_defaults airmont_params = { .p_gain_pct = 14, .d_gain_pct = 0, .i_gain_pct = 4, + .boost_iowait = true, }, .funcs = { .get_max = atom_get_max_pstate, @@ -1071,7 +1079,7 @@ static struct cpu_defaults airmont_params = { }, }; -static struct cpu_defaults knl_params = { +static const struct cpu_defaults knl_params = { .pid_policy = { .sample_rate_ms = 10, .deadband = 0, @@ -1091,7 +1099,7 @@ static struct cpu_defaults knl_params = { }, }; -static struct cpu_defaults bxt_params = { +static const struct cpu_defaults bxt_params = { .pid_policy = { .sample_rate_ms = 10, .deadband = 0, @@ -1099,6 +1107,7 @@ static struct cpu_defaults bxt_params = { .p_gain_pct = 14, .d_gain_pct = 0, .i_gain_pct = 4, + .boost_iowait = true, }, .funcs = { .get_max = core_get_max_pstate, @@ -1222,36 +1231,38 @@ static inline int32_t get_avg_pstate(struct cpudata *cpu) static inline int32_t get_target_pstate_use_cpu_load(struct cpudata *cpu) { struct sample *sample = &cpu->sample; - u64 cummulative_iowait, delta_iowait_us; - u64 delta_iowait_mperf; - u64 mperf, now; - int32_t cpu_load; + int32_t busy_frac, boost; + int target, avg_pstate; - cummulative_iowait = get_cpu_iowait_time_us(cpu->cpu, &now); + busy_frac = div_fp(sample->mperf, sample->tsc); - /* - * Convert iowait time into number of IO cycles spent at max_freq. - * IO is considered as busy only for the cpu_load algorithm. For - * performance this is not needed since we always try to reach the - * maximum P-State, so we are already boosting the IOs. - */ - delta_iowait_us = cummulative_iowait - cpu->prev_cummulative_iowait; - delta_iowait_mperf = div64_u64(delta_iowait_us * cpu->pstate.scaling * - cpu->pstate.max_pstate, MSEC_PER_SEC); + boost = cpu->iowait_boost; + cpu->iowait_boost >>= 1; + + if (busy_frac < boost) + busy_frac = boost; - mperf = cpu->sample.mperf + delta_iowait_mperf; - cpu->prev_cummulative_iowait = cummulative_iowait; + sample->busy_scaled = busy_frac * 100; + + target = limits->no_turbo || limits->turbo_disabled ? + cpu->pstate.max_pstate : cpu->pstate.turbo_pstate; + target += target >> 2; + target = mul_fp(target, busy_frac); + if (target < cpu->pstate.min_pstate) + target = cpu->pstate.min_pstate; /* - * 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. + * If the average P-state during the previous cycle was higher than the + * current target, add 50% of the difference to the target to reduce + * possible performance oscillations and offset possible performance + * loss related to moving the workload from one CPU to another within + * a package/module. */ - cpu_load = div64_u64(int_tofp(100) * mperf, sample->tsc); - cpu->sample.busy_scaled = cpu_load; + avg_pstate = get_avg_pstate(cpu); + if (avg_pstate > target) + target += (avg_pstate - target) >> 1; - return get_avg_pstate(cpu) - pid_calc(&cpu->pid, cpu_load); + return target; } static inline int32_t get_target_pstate_use_performance(struct cpudata *cpu) @@ -1260,10 +1271,11 @@ static inline int32_t get_target_pstate_use_performance(struct cpudata *cpu) u64 duration_ns; /* - * perf_scaled is the average performance during the last sampling - * period scaled by the ratio of the maximum P-state to the P-state - * requested last time (in percent). That measures the system's - * response to the previous P-state selection. + * perf_scaled is the ratio of the average P-state during the last + * sampling period to the P-state requested last time (in percent). + * + * That measures the system's response to the previous P-state + * selection. */ max_pstate = cpu->pstate.max_pstate_physical; current_pstate = cpu->pstate.current_pstate; @@ -1325,15 +1337,29 @@ static inline void intel_pstate_adjust_busy_pstate(struct cpudata *cpu) sample->mperf, sample->aperf, sample->tsc, - get_avg_frequency(cpu)); + get_avg_frequency(cpu), + fp_toint(cpu->iowait_boost * 100)); } static void intel_pstate_update_util(struct update_util_data *data, u64 time, - unsigned long util, unsigned long max) + unsigned int flags) { struct cpudata *cpu = container_of(data, struct cpudata, update_util); - u64 delta_ns = time - cpu->sample.time; + u64 delta_ns; + + if (pid_params.boost_iowait) { + if (flags & SCHED_CPUFREQ_IOWAIT) { + cpu->iowait_boost = int_tofp(1); + } else if (cpu->iowait_boost) { + /* Clear iowait_boost if the CPU may have been idle. */ + delta_ns = time - cpu->last_update; + if (delta_ns > TICK_NSEC) + cpu->iowait_boost = 0; + } + cpu->last_update = time; + } + delta_ns = time - cpu->sample.time; if ((s64)delta_ns >= pid_params.sample_rate_ns) { bool sample_taken = intel_pstate_sample(cpu, time); |