1
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}
84
