182 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2/* cpufreq-bench CPUFreq microbenchmark3 *4 * Copyright (C) 2008 Christian Kornacker <ckornacker@suse.de>5 */6 7#include <stdio.h>8#include <unistd.h>9#include <math.h>10 11#include "config.h"12#include "system.h"13#include "benchmark.h"14 15/* Print out progress if we log into a file */16#define show_progress(total_time, progress_time) \17if (config->output != stdout) { \18 fprintf(stdout, "Progress: %02lu %%\r", \19 (progress_time * 100) / total_time); \20 fflush(stdout); \21}22 23/**24 * compute how many rounds of calculation we should do25 * to get the given load time26 *27 * @param load aimed load time in µs28 *29 * @retval rounds of calculation30 **/31 32unsigned int calculate_timespace(long load, struct config *config)33{34 int i;35 long long now, then;36 unsigned int estimated = GAUGECOUNT;37 unsigned int rounds = 0;38 unsigned int timed = 0;39 40 if (config->verbose)41 printf("calibrating load of %lius, please wait...\n", load);42 43 /* get the initial calculation time for a specific number of rounds */44 now = get_time();45 ROUNDS(estimated);46 then = get_time();47 48 timed = (unsigned int)(then - now);49 50 /* approximation of the wanted load time by comparing with the51 * initial calculation time */52 for (i = 0; i < 4; i++) {53 rounds = (unsigned int)(load * estimated / timed);54 dprintf("calibrating with %u rounds\n", rounds);55 now = get_time();56 ROUNDS(rounds);57 then = get_time();58 59 timed = (unsigned int)(then - now);60 estimated = rounds;61 }62 if (config->verbose)63 printf("calibration done\n");64 65 return estimated;66}67 68/**69 * benchmark70 * generates a specific sleep an load time with the performance71 * governor and compares the used time for same calculations done72 * with the configured powersave governor73 *74 * @param config config values for the benchmark75 *76 **/77 78void start_benchmark(struct config *config)79{80 unsigned int _round, cycle;81 long long now, then;82 long sleep_time = 0, load_time = 0;83 long performance_time = 0, powersave_time = 0;84 unsigned int calculations;85 unsigned long total_time = 0, progress_time = 0;86 87 sleep_time = config->sleep;88 load_time = config->load;89 90 /* For the progress bar */91 for (_round = 1; _round <= config->rounds; _round++)92 total_time += _round * (config->sleep + config->load);93 total_time *= 2; /* powersave and performance cycles */94 95 for (_round = 0; _round < config->rounds; _round++) {96 performance_time = 0LL;97 powersave_time = 0LL;98 99 show_progress(total_time, progress_time);100 101 /* set the cpufreq governor to "performance" which disables102 * P-State switching. */103 if (set_cpufreq_governor("performance", config->cpu) != 0)104 return;105 106 /* calibrate the calculation time. the resulting calculation107 * _rounds should produce a load which matches the configured108 * load time */109 calculations = calculate_timespace(load_time, config);110 111 if (config->verbose)112 printf("_round %i: doing %u cycles with %u calculations"113 " for %lius\n", _round + 1, config->cycles,114 calculations, load_time);115 116 fprintf(config->output, "%u %li %li ",117 _round, load_time, sleep_time);118 119 if (config->verbose)120 printf("average: %lius, rps:%li\n",121 load_time / calculations,122 1000000 * calculations / load_time);123 124 /* do some sleep/load cycles with the performance governor */125 for (cycle = 0; cycle < config->cycles; cycle++) {126 now = get_time();127 usleep(sleep_time);128 ROUNDS(calculations);129 then = get_time();130 performance_time += then - now - sleep_time;131 if (config->verbose)132 printf("performance cycle took %lius, "133 "sleep: %lius, "134 "load: %lius, rounds: %u\n",135 (long)(then - now), sleep_time,136 load_time, calculations);137 }138 fprintf(config->output, "%li ",139 performance_time / config->cycles);140 141 progress_time += sleep_time + load_time;142 show_progress(total_time, progress_time);143 144 /* set the powersave governor which activates P-State switching145 * again */146 if (set_cpufreq_governor(config->governor, config->cpu) != 0)147 return;148 149 /* again, do some sleep/load cycles with the150 * powersave governor */151 for (cycle = 0; cycle < config->cycles; cycle++) {152 now = get_time();153 usleep(sleep_time);154 ROUNDS(calculations);155 then = get_time();156 powersave_time += then - now - sleep_time;157 if (config->verbose)158 printf("powersave cycle took %lius, "159 "sleep: %lius, "160 "load: %lius, rounds: %u\n",161 (long)(then - now), sleep_time,162 load_time, calculations);163 }164 165 progress_time += sleep_time + load_time;166 167 /* compare the average sleep/load cycles */168 fprintf(config->output, "%li ",169 powersave_time / config->cycles);170 fprintf(config->output, "%.3f\n",171 performance_time * 100.0 / powersave_time);172 fflush(config->output);173 174 if (config->verbose)175 printf("performance is at %.2f%%\n",176 performance_time * 100.0 / powersave_time);177 178 sleep_time += config->sleep_step;179 load_time += config->load_step;180 }181}182