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1/* ADJ_FREQ Skew change test2 * by: john stultz (johnstul@us.ibm.com)3 * (C) Copyright IBM 20124 * Licensed under the GPLv25 *6 * NOTE: This is a meta-test which cranks the ADJ_FREQ knob and7 * then uses other tests to detect problems. Thus this test requires8 * that the raw_skew, inconsistency-check and nanosleep tests be9 * present in the same directory it is run from.10 *11 * To build:12 * $ gcc change_skew.c -o change_skew -lrt13 *14 * This program is free software: you can redistribute it and/or modify15 * it under the terms of the GNU General Public License as published by16 * the Free Software Foundation, either version 2 of the License, or17 * (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 of21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the22 * 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 33int change_skew_test(int ppm)34{35 struct timex tx;36 int ret;37 38 tx.modes = ADJ_FREQUENCY;39 tx.freq = ppm << 16;40 41 ret = adjtimex(&tx);42 if (ret < 0) {43 printf("Error adjusting freq\n");44 return ret;45 }46 47 ret = system("./raw_skew");48 ret |= system("./inconsistency-check");49 ret |= system("./nanosleep");50 51 return ret;52}53 54 55int main(int argc, char **argv)56{57 struct timex tx;58 int i, ret;59 60 int ppm[5] = {0, 250, 500, -250, -500};61 62 /* Kill ntpd */63 ret = system("killall -9 ntpd");64 65 /* Make sure there's no offset adjustment going on */66 tx.modes = ADJ_OFFSET;67 tx.offset = 0;68 ret = adjtimex(&tx);69 70 if (ret < 0) {71 printf("Maybe you're not running as root?\n");72 return -1;73 }74 75 for (i = 0; i < 5; i++) {76 printf("Using %i ppm adjustment\n", ppm[i]);77 ret = change_skew_test(ppm[i]);78 if (ret)79 break;80 }81 82 /* Set things back */83 tx.modes = ADJ_FREQUENCY;84 tx.offset = 0;85 adjtimex(&tx);86 87 if (ret) {88 printf("[FAIL]");89 ksft_exit_fail();90 }91 printf("[OK]");92 ksft_exit_pass();93}94