94 lines · c
1// SPDX-License-Identifier: GPL-2.02#include <math.h>3#include <unistd.h>4#include <stdio.h>5#include <stdlib.h>6#include <sys/types.h>7#include <sys/stat.h>8#include <fcntl.h>9#include <sys/timeb.h>10#include <sched.h>11#include <errno.h>12#include <string.h>13#include <time.h>14#include "../kselftest.h"15 16#define MSEC_PER_SEC 1000L17#define NSEC_PER_MSEC 1000000L18 19void usage(char *name) {20 printf ("Usage: %s cpunum\n", name);21}22 23int main(int argc, char **argv) {24 unsigned int i, cpu, fd;25 char msr_file_name[64];26 long long tsc, old_tsc, new_tsc;27 long long aperf, old_aperf, new_aperf;28 long long mperf, old_mperf, new_mperf;29 struct timespec before, after;30 long long int start, finish, total;31 cpu_set_t cpuset;32 33 if (argc != 2) {34 usage(argv[0]);35 return 1;36 }37 38 errno = 0;39 cpu = strtol(argv[1], (char **) NULL, 10);40 41 if (errno) {42 usage(argv[0]);43 return 1;44 }45 46 sprintf(msr_file_name, "/dev/cpu/%d/msr", cpu);47 fd = open(msr_file_name, O_RDONLY);48 49 if (fd == -1) {50 printf("/dev/cpu/%d/msr: %s\n", cpu, strerror(errno));51 return KSFT_SKIP;52 }53 54 CPU_ZERO(&cpuset);55 CPU_SET(cpu, &cpuset);56 57 if (sched_setaffinity(0, sizeof(cpu_set_t), &cpuset)) {58 perror("Failed to set cpu affinity");59 return 1;60 }61 62 if (clock_gettime(CLOCK_MONOTONIC, &before) < 0) {63 perror("clock_gettime");64 return 1;65 }66 pread(fd, &old_tsc, sizeof(old_tsc), 0x10);67 pread(fd, &old_aperf, sizeof(old_mperf), 0xe7);68 pread(fd, &old_mperf, sizeof(old_aperf), 0xe8);69 70 for (i=0; i<0x8fffffff; i++) {71 sqrt(i);72 }73 74 if (clock_gettime(CLOCK_MONOTONIC, &after) < 0) {75 perror("clock_gettime");76 return 1;77 }78 pread(fd, &new_tsc, sizeof(new_tsc), 0x10);79 pread(fd, &new_aperf, sizeof(new_mperf), 0xe7);80 pread(fd, &new_mperf, sizeof(new_aperf), 0xe8);81 82 tsc = new_tsc-old_tsc;83 aperf = new_aperf-old_aperf;84 mperf = new_mperf-old_mperf;85 86 start = before.tv_sec*MSEC_PER_SEC + before.tv_nsec/NSEC_PER_MSEC;87 finish = after.tv_sec*MSEC_PER_SEC + after.tv_nsec/NSEC_PER_MSEC;88 total = finish - start;89 90 printf("runTime: %4.2f\n", 1.0*total/MSEC_PER_SEC);91 printf("freq: %7.0f\n", tsc / (1.0*aperf / (1.0 * mperf)) / total);92 return 0;93}94