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Linux kernel mirror (for testing)
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1/* ADJ_FREQ Skew consistency test
2 * by: john stultz (johnstul@us.ibm.com)
3 * (C) Copyright IBM 2012
4 * Licensed under the GPLv2
5 *
6 * NOTE: This is a meta-test which cranks the ADJ_FREQ knob back
7 * and forth and watches for consistency problems. Thus this test requires
8 * that the inconsistency-check tests be present in the same directory it
9 * is run from.
10 *
11 * To build:
12 * $ gcc skew_consistency.c -o skew_consistency -lrt
13 *
14 * This program is free software: you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation, either version 2 of the License, or
17 * (at your option) any later version.
18 *
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
23 */
24
25
26#include <stdio.h>
27#include <stdlib.h>
28#include <unistd.h>
29#include <sys/time.h>
30#include <sys/timex.h>
31#include <time.h>
32#include <sys/types.h>
33#include <sys/stat.h>
34#include <fcntl.h>
35#include <string.h>
36#include <sys/wait.h>
37#include "kselftest.h"
38
39int main(int argc, char **argv)
40{
41 struct timex tx;
42 int ret, ppm;
43 pid_t pid;
44
45
46 printf("Running Asynchronous Frequency Changing Tests...\n");
47
48 pid = fork();
49 if (!pid)
50 return system("./inconsistency-check -t 60");
51
52 ppm = 500;
53 ret = 0;
54
55 while (pid != waitpid(pid, &ret, WNOHANG)) {
56 ppm = -ppm;
57 tx.modes = ADJ_FREQUENCY;
58 tx.freq = ppm << 16;
59 adjtimex(&tx);
60 usleep(500000);
61 }
62
63 /* Set things back */
64 tx.modes = ADJ_FREQUENCY;
65 tx.offset = 0;
66 adjtimex(&tx);
67
68
69 if (ret) {
70 printf("[FAILED]\n");
71 ksft_exit_fail();
72 }
73 printf("[OK]\n");
74 ksft_exit_pass();
75}