1// SPDX-License-Identifier: GPL-2.0
 2#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 "../kselftest.h"
14
15void usage(char *name) {
16	printf ("Usage: %s cpunum\n", name);
17}
18
19int main(int argc, char **argv) {
20	unsigned int i, cpu, fd;
21	char msr_file_name[64];
22	long long tsc, old_tsc, new_tsc;
23	long long aperf, old_aperf, new_aperf;
24	long long mperf, old_mperf, new_mperf;
25	struct timeb before, after;
26	long long int start, finish, total;
27	cpu_set_t cpuset;
28
29	if (argc != 2) {
30		usage(argv[0]);
31		return 1;
32	}
33
34	errno = 0;
35	cpu = strtol(argv[1], (char **) NULL, 10);
36
37	if (errno) {
38		usage(argv[0]);
39		return 1;
40	}
41
42	sprintf(msr_file_name, "/dev/cpu/%d/msr", cpu);
43	fd = open(msr_file_name, O_RDONLY);
44
45	if (fd == -1) {
46		printf("/dev/cpu/%d/msr: %s\n", cpu, strerror(errno));
47		return KSFT_SKIP;
48	}
49
50	CPU_ZERO(&cpuset);
51	CPU_SET(cpu, &cpuset);
52
53	if (sched_setaffinity(0, sizeof(cpu_set_t), &cpuset)) {
54		perror("Failed to set cpu affinity");
55		return 1;
56	}
57
58	ftime(&before);
59	pread(fd, &old_tsc,  sizeof(old_tsc), 0x10);
60	pread(fd, &old_aperf,  sizeof(old_mperf), 0xe7);
61	pread(fd, &old_mperf,  sizeof(old_aperf), 0xe8);
62
63	for (i=0; i<0x8fffffff; i++) {
64		sqrt(i);
65	}
66
67	ftime(&after);
68	pread(fd, &new_tsc,  sizeof(new_tsc), 0x10);
69	pread(fd, &new_aperf,  sizeof(new_mperf), 0xe7);
70	pread(fd, &new_mperf,  sizeof(new_aperf), 0xe8);
71
72	tsc = new_tsc-old_tsc;
73	aperf = new_aperf-old_aperf;
74	mperf = new_mperf-old_mperf;
75
76	start = before.time*1000 + before.millitm;
77	finish = after.time*1000 + after.millitm;
78	total = finish - start;
79
80	printf("runTime: %4.2f\n", 1.0*total/1000);
81	printf("freq: %7.0f\n", tsc / (1.0*aperf / (1.0 * mperf)) / total);
82	return 0;
83}