180 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 <time.h>9#include <sys/time.h>10#include <sys/types.h>11#include <unistd.h>12 13#include <sched.h>14 15#include <cpufreq.h>16#include <cpupower.h>17 18#include "config.h"19#include "system.h"20 21/**22 * returns time since epoch in µs23 *24 * @retval time25 **/26 27long long int get_time()28{29 struct timeval now;30 31 gettimeofday(&now, NULL);32 33 return (long long int)(now.tv_sec * 1000000LL + now.tv_usec);34}35 36/**37 * sets the cpufreq governor38 *39 * @param governor cpufreq governor name40 * @param cpu cpu for which the governor should be set41 *42 * @retval 0 on success43 * @retval -1 when failed44 **/45 46int set_cpufreq_governor(char *governor, unsigned int cpu)47{48 49 dprintf("set %s as cpufreq governor\n", governor);50 51 if (cpupower_is_cpu_online(cpu) != 1) {52 perror("cpufreq_cpu_exists");53 fprintf(stderr, "error: cpu %u does not exist\n", cpu);54 return -1;55 }56 57 if (cpufreq_modify_policy_governor(cpu, governor) != 0) {58 perror("cpufreq_modify_policy_governor");59 fprintf(stderr, "error: unable to set %s governor\n", governor);60 return -1;61 }62 63 return 0;64}65 66/**67 * sets cpu affinity for the process68 *69 * @param cpu cpu# to which the affinity should be set70 *71 * @retval 0 on success72 * @retval -1 when setting the affinity failed73 **/74 75int set_cpu_affinity(unsigned int cpu)76{77 cpu_set_t cpuset;78 79 CPU_ZERO(&cpuset);80 CPU_SET(cpu, &cpuset);81 82 dprintf("set affinity to cpu #%u\n", cpu);83 84 if (sched_setaffinity(getpid(), sizeof(cpu_set_t), &cpuset) < 0) {85 perror("sched_setaffinity");86 fprintf(stderr, "warning: unable to set cpu affinity\n");87 return -1;88 }89 90 return 0;91}92 93/**94 * sets the process priority parameter95 *96 * @param priority priority value97 *98 * @retval 0 on success99 * @retval -1 when setting the priority failed100 **/101 102int set_process_priority(int priority)103{104 struct sched_param param;105 106 dprintf("set scheduler priority to %i\n", priority);107 108 param.sched_priority = priority;109 110 if (sched_setscheduler(0, SCHEDULER, ¶m) < 0) {111 perror("sched_setscheduler");112 fprintf(stderr, "warning: unable to set scheduler priority\n");113 return -1;114 }115 116 return 0;117}118 119/**120 * notifies the user that the benchmark may run some time121 *122 * @param config benchmark config values123 *124 **/125 126void prepare_user(const struct config *config)127{128 unsigned long sleep_time = 0;129 unsigned long load_time = 0;130 unsigned int round;131 132 for (round = 0; round < config->rounds; round++) {133 sleep_time += 2 * config->cycles *134 (config->sleep + config->sleep_step * round);135 load_time += 2 * config->cycles *136 (config->load + config->load_step * round) +137 (config->load + config->load_step * round * 4);138 }139 140 if (config->verbose || config->output != stdout)141 printf("approx. test duration: %im\n",142 (int)((sleep_time + load_time) / 60000000));143}144 145/**146 * sets up the cpu affinity and scheduler priority147 *148 * @param config benchmark config values149 *150 **/151 152void prepare_system(const struct config *config)153{154 if (config->verbose)155 printf("set cpu affinity to cpu #%u\n", config->cpu);156 157 set_cpu_affinity(config->cpu);158 159 switch (config->prio) {160 case SCHED_HIGH:161 if (config->verbose)162 printf("high priority condition requested\n");163 164 set_process_priority(PRIORITY_HIGH);165 break;166 case SCHED_LOW:167 if (config->verbose)168 printf("low priority condition requested\n");169 170 set_process_priority(PRIORITY_LOW);171 break;172 default:173 if (config->verbose)174 printf("default priority condition requested\n");175 176 set_process_priority(PRIORITY_DEFAULT);177 }178}179 180