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Diffstat (limited to 'tools/power/cpupower/bench/benchmark.c')
| -rw-r--r-- | tools/power/cpupower/bench/benchmark.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/tools/power/cpupower/bench/benchmark.c b/tools/power/cpupower/bench/benchmark.c new file mode 100644 index 00000000000..f538633b8b4 --- /dev/null +++ b/tools/power/cpupower/bench/benchmark.c @@ -0,0 +1,184 @@ +/* cpufreq-bench CPUFreq microbenchmark + * + * Copyright (C) 2008 Christian Kornacker <ckornacker@suse.de> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +#include <stdio.h> +#include <unistd.h> +#include <math.h> + +#include "config.h" +#include "system.h" +#include "benchmark.h" + +/* Print out progress if we log into a file */ +#define show_progress(total_time, progress_time) \ +if (config->output != stdout) { \ + fprintf(stdout, "Progress: %02lu %%\r", \ + (progress_time * 100) / total_time); \ + fflush(stdout); \ +} + +/** + * compute how many rounds of calculation we should do + * to get the given load time + * + * @param load aimed load time in µs + * + * @retval rounds of calculation + **/ + +unsigned int calculate_timespace(long load, struct config *config) +{ + int i; + long long now, then; + unsigned int estimated = GAUGECOUNT; + unsigned int rounds = 0; + unsigned int timed = 0; + + if (config->verbose) + printf("calibrating load of %lius, please wait...\n", load); + + /* get the initial calculation time for a specific number of rounds */ + now = get_time(); + ROUNDS(estimated); + then = get_time(); + + timed = (unsigned int)(then - now); + + /* approximation of the wanted load time by comparing with the + * initial calculation time */ + for (i= 0; i < 4; i++) + { + rounds = (unsigned int)(load * estimated / timed); + dprintf("calibrating with %u rounds\n", rounds); + now = get_time(); + ROUNDS(rounds); + then = get_time(); + + timed = (unsigned int)(then - now); + estimated = rounds; + } + if (config->verbose) + printf("calibration done\n"); + + return estimated; +} + +/** + * benchmark + * generates a specific sleep an load time with the performance + * governor and compares the used time for same calculations done + * with the configured powersave governor + * + * @param config config values for the benchmark + * + **/ + +void start_benchmark(struct config *config) +{ + unsigned int _round, cycle; + long long now, then; + long sleep_time = 0, load_time = 0; + long performance_time = 0, powersave_time = 0; + unsigned int calculations; + unsigned long total_time = 0, progress_time = 0; + + sleep_time = config->sleep; + load_time = config->load; + + /* For the progress bar */ + for (_round=1; _round <= config->rounds; _round++) + total_time += _round * (config->sleep + config->load); + total_time *= 2; /* powersave and performance cycles */ + + for (_round=0; _round < config->rounds; _round++) { + performance_time = 0LL; + powersave_time = 0LL; + + show_progress(total_time, progress_time); + + /* set the cpufreq governor to "performance" which disables + * P-State switching. */ + if (set_cpufreq_governor("performance", config->cpu) != 0) + return; + + /* calibrate the calculation time. the resulting calculation + * _rounds should produce a load which matches the configured + * load time */ + calculations = calculate_timespace(load_time, config); + + if (config->verbose) + printf("_round %i: doing %u cycles with %u calculations" + " for %lius\n", _round + 1, config->cycles, + calculations, load_time); + + fprintf(config->output, "%u %li %li ", + _round, load_time, sleep_time); + + if (config->verbose) { + printf("avarage: %lius, rps:%li\n", load_time / calculations, 1000000 * calculations / load_time); + } + + /* do some sleep/load cycles with the performance governor */ + for (cycle = 0; cycle < config->cycles; cycle++) { + now = get_time(); + usleep(sleep_time); + ROUNDS(calculations); + then = get_time(); + performance_time += then - now - sleep_time; + if (config->verbose) + printf("performance cycle took %lius, sleep: %lius, load: %lius, rounds: %u\n", + (long)(then - now), sleep_time, load_time, calculations); + } + fprintf(config->output, "%li ", performance_time / config->cycles); + + progress_time += sleep_time + load_time; + show_progress(total_time, progress_time); + + /* set the powersave governor which activates P-State switching + * again */ + if (set_cpufreq_governor(config->governor, config->cpu) != 0) + return; + + /* again, do some sleep/load cycles with the powersave governor */ + for (cycle = 0; cycle < config->cycles; cycle++) { + now = get_time(); + usleep(sleep_time); + ROUNDS(calculations); + then = get_time(); + powersave_time += then - now - sleep_time; + if (config->verbose) + printf("powersave cycle took %lius, sleep: %lius, load: %lius, rounds: %u\n", + (long)(then - now), sleep_time, load_time, calculations); + } + + progress_time += sleep_time + load_time; + + /* compare the avarage sleep/load cycles */ + fprintf(config->output, "%li ", powersave_time / config->cycles); + fprintf(config->output, "%.3f\n", performance_time * 100.0 / powersave_time); + fflush(config->output); + + if (config->verbose) + printf("performance is at %.2f%%\n", performance_time * 100.0 / powersave_time); + + sleep_time += config->sleep_step; + load_time += config->load_step; + } +} + |