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#include "../kselftest.h"
  32
  33#define NSEC_PER_SEC 1000000000LL
  34
  35
  36int change_skew_test(int ppm)
  37{
  38        struct timex tx;
  39        int ret;
  40
  41        tx.modes = ADJ_FREQUENCY;
  42        tx.freq = ppm << 16;
  43
  44        ret = adjtimex(&tx);
  45        if (ret < 0) {
  46                printf("Error adjusting freq\n");
  47                return ret;
  48        }
  49
  50        ret = system("./raw_skew");
  51        ret |= system("./inconsistency-check");
  52        ret |= system("./nanosleep");
  53
  54        return ret;
  55}
  56
  57
  58int main(int argv, char **argc)
  59{
  60        struct timex tx;
  61        int i, ret;
  62
  63        int ppm[5] = {0, 250, 500, -250, -500};
  64
  65        /* Kill ntpd */
  66        ret = system("killall -9 ntpd");
  67
  68        /* Make sure there's no offset adjustment going on */
  69        tx.modes = ADJ_OFFSET;
  70        tx.offset = 0;
  71        ret = adjtimex(&tx);
  72
  73        if (ret < 0) {
  74                printf("Maybe you're not running as root?\n");
  75                return -1;
  76        }
  77
  78        for (i = 0; i < 5; i++) {
  79                printf("Using %i ppm adjustment\n", ppm[i]);
  80                ret = change_skew_test(ppm[i]);
  81                if (ret)
  82                        break;
  83        }
  84
  85        /* Set things back */
  86        tx.modes = ADJ_FREQUENCY;
  87        tx.offset = 0;
  88        adjtimex(&tx);
  89
  90        if (ret) {
  91                printf("[FAIL]");
  92                return ksft_exit_fail();
  93        }
  94        printf("[OK]");
  95        return ksft_exit_pass();
  96}
  97