diff options
Diffstat (limited to 'tools/power/cpupower/utils/idle_monitor/mperf_monitor.c')
| -rw-r--r-- | tools/power/cpupower/utils/idle_monitor/mperf_monitor.c | 258 |
1 files changed, 258 insertions, 0 deletions
diff --git a/tools/power/cpupower/utils/idle_monitor/mperf_monitor.c b/tools/power/cpupower/utils/idle_monitor/mperf_monitor.c new file mode 100644 index 000000000000..f8545e40e232 --- /dev/null +++ b/tools/power/cpupower/utils/idle_monitor/mperf_monitor.c @@ -0,0 +1,258 @@ +/* + * (C) 2010,2011 Thomas Renninger <trenn@suse.de>, Novell Inc. + * + * Licensed under the terms of the GNU GPL License version 2. + */ + +#if defined(__i386__) || defined(__x86_64__) + +#include <stdio.h> +#include <stdint.h> +#include <stdlib.h> +#include <string.h> +#include <limits.h> + +#include <cpufreq.h> + +#include "helpers/helpers.h" +#include "idle_monitor/cpupower-monitor.h" + +#define MSR_APERF 0xE8 +#define MSR_MPERF 0xE7 + +#define MSR_TSC 0x10 + +enum mperf_id { C0 = 0, Cx, AVG_FREQ, MPERF_CSTATE_COUNT }; + +static int mperf_get_count_percent(unsigned int self_id, double *percent, + unsigned int cpu); +static int mperf_get_count_freq(unsigned int id, unsigned long long *count, + unsigned int cpu); + +static cstate_t mperf_cstates[MPERF_CSTATE_COUNT] = { + { + .name = "C0", + .desc = N_("Processor Core not idle"), + .id = C0, + .range = RANGE_THREAD, + .get_count_percent = mperf_get_count_percent, + }, + { + .name = "Cx", + .desc = N_("Processor Core in an idle state"), + .id = Cx, + .range = RANGE_THREAD, + .get_count_percent = mperf_get_count_percent, + }, + + { + .name = "Freq", + .desc = N_("Average Frequency (including boost) in MHz"), + .id = AVG_FREQ, + .range = RANGE_THREAD, + .get_count = mperf_get_count_freq, + }, +}; + +static unsigned long long tsc_at_measure_start; +static unsigned long long tsc_at_measure_end; +static unsigned long max_frequency; +static unsigned long long *mperf_previous_count; +static unsigned long long *aperf_previous_count; +static unsigned long long *mperf_current_count; +static unsigned long long *aperf_current_count; +/* valid flag for all CPUs. If a MSR read failed it will be zero */ +static int *is_valid; + +static int mperf_get_tsc(unsigned long long *tsc) +{ + return read_msr(0, MSR_TSC, tsc); +} + +static int mperf_init_stats(unsigned int cpu) +{ + unsigned long long val; + int ret; + + ret = read_msr(cpu, MSR_APERF, &val); + aperf_previous_count[cpu] = val; + ret |= read_msr(cpu, MSR_MPERF, &val); + mperf_previous_count[cpu] = val; + is_valid[cpu] = !ret; + + return 0; +} + +static int mperf_measure_stats(unsigned int cpu) +{ + unsigned long long val; + int ret; + + ret = read_msr(cpu, MSR_APERF, &val); + aperf_current_count[cpu] = val; + ret |= read_msr(cpu, MSR_MPERF, &val); + mperf_current_count[cpu] = val; + is_valid[cpu] = !ret; + + return 0; +} + +/* + * get_average_perf() + * + * Returns the average performance (also considers boosted frequencies) + * + * Input: + * aperf_diff: Difference of the aperf register over a time period + * mperf_diff: Difference of the mperf register over the same time period + * max_freq: Maximum frequency (P0) + * + * Returns: + * Average performance over the time period + */ +static unsigned long get_average_perf(unsigned long long aperf_diff, + unsigned long long mperf_diff) +{ + unsigned int perf_percent = 0; + if (((unsigned long)(-1) / 100) < aperf_diff) { + int shift_count = 7; + aperf_diff >>= shift_count; + mperf_diff >>= shift_count; + } + perf_percent = (aperf_diff * 100) / mperf_diff; + return (max_frequency * perf_percent) / 100; +} + +static int mperf_get_count_percent(unsigned int id, double *percent, + unsigned int cpu) +{ + unsigned long long aperf_diff, mperf_diff, tsc_diff; + + if (!is_valid[cpu]) + return -1; + + if (id != C0 && id != Cx) + return -1; + + mperf_diff = mperf_current_count[cpu] - mperf_previous_count[cpu]; + aperf_diff = aperf_current_count[cpu] - aperf_previous_count[cpu]; + tsc_diff = tsc_at_measure_end - tsc_at_measure_start; + + *percent = 100.0 * mperf_diff / tsc_diff; + dprint("%s: mperf_diff: %llu, tsc_diff: %llu\n", + mperf_cstates[id].name, mperf_diff, tsc_diff); + + if (id == Cx) + *percent = 100.0 - *percent; + + dprint("%s: previous: %llu - current: %llu - (%u)\n", mperf_cstates[id].name, + mperf_diff, aperf_diff, cpu); + dprint("%s: %f\n", mperf_cstates[id].name, *percent); + return 0; +} + +static int mperf_get_count_freq(unsigned int id, unsigned long long *count, + unsigned int cpu) +{ + unsigned long long aperf_diff, mperf_diff; + + if (id != AVG_FREQ) + return 1; + + if (!is_valid[cpu]) + return -1; + + mperf_diff = mperf_current_count[cpu] - mperf_previous_count[cpu]; + aperf_diff = aperf_current_count[cpu] - aperf_previous_count[cpu]; + + /* Return MHz for now, might want to return KHz if column width is more + generic */ + *count = get_average_perf(aperf_diff, mperf_diff) / 1000; + dprint("%s: %llu\n", mperf_cstates[id].name, *count); + + return 0; +} + +static int mperf_start(void) +{ + int cpu; + unsigned long long dbg; + + mperf_get_tsc(&tsc_at_measure_start); + + for (cpu = 0; cpu < cpu_count; cpu++) + mperf_init_stats(cpu); + + mperf_get_tsc(&dbg); + dprint("TSC diff: %llu\n", dbg - tsc_at_measure_start); + return 0; +} + +static int mperf_stop(void) +{ + unsigned long long dbg; + int cpu; + + mperf_get_tsc(&tsc_at_measure_end); + + for (cpu = 0; cpu < cpu_count; cpu++) + mperf_measure_stats(cpu); + + mperf_get_tsc(&dbg); + dprint("TSC diff: %llu\n", dbg - tsc_at_measure_end); + + return 0; +} + +struct cpuidle_monitor mperf_monitor; + +struct cpuidle_monitor* mperf_register(void) { + + unsigned long min; + + if (!(cpupower_cpu_info.caps & CPUPOWER_CAP_APERF)) + return NULL; + + /* Assume min/max all the same on all cores */ + if (cpufreq_get_hardware_limits(0, &min, &max_frequency)) { + dprint("Cannot retrieve max freq from cpufreq kernel " + "subsystem\n"); + return NULL; + } + + /* Free this at program termination */ + is_valid = calloc(cpu_count, sizeof (int)); + mperf_previous_count = calloc (cpu_count, + sizeof(unsigned long long)); + aperf_previous_count = calloc (cpu_count, + sizeof(unsigned long long)); + mperf_current_count = calloc (cpu_count, + sizeof(unsigned long long)); + aperf_current_count = calloc (cpu_count, + sizeof(unsigned long long)); + + mperf_monitor.name_len = strlen(mperf_monitor.name); + return &mperf_monitor; +} + +void mperf_unregister(void) { + free(mperf_previous_count); + free(aperf_previous_count); + free(mperf_current_count); + free(aperf_current_count); + free(is_valid); +} + +struct cpuidle_monitor mperf_monitor = { + .name = "Mperf", + .hw_states_num = MPERF_CSTATE_COUNT, + .hw_states = mperf_cstates, + .start = mperf_start, + .stop = mperf_stop, + .do_register = mperf_register, + .unregister = mperf_unregister, + .needs_root = 1, + .overflow_s = 922000000 /* 922337203 seconds TSC overflow + at 20GHz */ +}; +#endif /* #if defined(__i386__) || defined(__x86_64__) */ |