LXR linux/tools/testing/selftests/timers/change

   1/* ADJ_FREQ Skew change 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 and
   7 *  then uses other tests to detect problems. Thus this test requires
   8 *  that the raw_skew, inconsistency-check and nanosleep tests be
   9 *  present in the same directory it is run from.
  10 *
  11 *  To build:
  12 *      $ gcc change_skew.c -o change_skew -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 <sys/time.h>
  29#include <sys/timex.h>
  30#include <time.h>
  31#ifdef KTEST
  32#include "../kselftest.h"
  33#else
  34static inline int ksft_exit_pass(void)
  35{
  36        exit(0);
  37}
  38static inline int ksft_exit_fail(void)
  39{
  40        exit(1);
  41}
  42#endif
  43
  44#define NSEC_PER_SEC 1000000000LL
  45
  46
  47int change_skew_test(int ppm)
  48{
  49        struct timex tx;
  50        int ret;
  51
  52        tx.modes = ADJ_FREQUENCY;
  53        tx.freq = ppm << 16;
  54
  55        ret = adjtimex(&tx);
  56        if (ret < 0) {
  57                printf("Error adjusting freq\n");
  58                return ret;
  59        }
  60
  61        ret = system("./raw_skew");
  62        ret |= system("./inconsistency-check");
  63        ret |= system("./nanosleep");
  64
  65        return ret;
  66}
  67
  68
  69int main(int argv, char **argc)
  70{
  71        struct timex tx;
  72        int i, ret;
  73
  74        int ppm[5] = {0, 250, 500, -250, -500};
  75
  76        /* Kill ntpd */
  77        ret = system("killall -9 ntpd");
  78
  79        /* Make sure there's no offset adjustment going on */
  80        tx.modes = ADJ_OFFSET;
  81        tx.offset = 0;
  82        ret = adjtimex(&tx);
  83
  84        if (ret < 0) {
  85                printf("Maybe you're not running as root?\n");
  86                return -1;
  87        }
  88
  89        for (i = 0; i < 5; i++) {
  90                printf("Using %i ppm adjustment\n", ppm[i]);
  91                ret = change_skew_test(ppm[i]);
  92                if (ret)
  93                        break;
  94        }
  95
  96        /* Set things back */
  97        tx.modes = ADJ_FREQUENCY;
  98        tx.offset = 0;
  99        adjtimex(&tx);
 100
 101        if (ret) {
 102                printf("[FAIL]");
 103                return ksft_exit_fail();
 104        }
 105        printf("[OK]");
 106        return ksft_exit_pass();
 107}
 108