linux/linux-5.4.31/tools/testing/selftests/timers/change_skew.c

97 lines
2.1 KiB
C

/* ADJ_FREQ Skew change test
* by: john stultz (johnstul@us.ibm.com)
* (C) Copyright IBM 2012
* Licensed under the GPLv2
*
* NOTE: This is a meta-test which cranks the ADJ_FREQ knob and
* then uses other tests to detect problems. Thus this test requires
* that the raw_skew, inconsistency-check and nanosleep tests be
* present in the same directory it is run from.
*
* To build:
* $ gcc change_skew.c -o change_skew -lrt
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <stdio.h>
#include <stdlib.h>
#include <sys/time.h>
#include <sys/timex.h>
#include <time.h>
#include "../kselftest.h"
#define NSEC_PER_SEC 1000000000LL
int change_skew_test(int ppm)
{
struct timex tx;
int ret;
tx.modes = ADJ_FREQUENCY;
tx.freq = ppm << 16;
ret = adjtimex(&tx);
if (ret < 0) {
printf("Error adjusting freq\n");
return ret;
}
ret = system("./raw_skew");
ret |= system("./inconsistency-check");
ret |= system("./nanosleep");
return ret;
}
int main(int argv, char **argc)
{
struct timex tx;
int i, ret;
int ppm[5] = {0, 250, 500, -250, -500};
/* Kill ntpd */
ret = system("killall -9 ntpd");
/* Make sure there's no offset adjustment going on */
tx.modes = ADJ_OFFSET;
tx.offset = 0;
ret = adjtimex(&tx);
if (ret < 0) {
printf("Maybe you're not running as root?\n");
return -1;
}
for (i = 0; i < 5; i++) {
printf("Using %i ppm adjustment\n", ppm[i]);
ret = change_skew_test(ppm[i]);
if (ret)
break;
}
/* Set things back */
tx.modes = ADJ_FREQUENCY;
tx.offset = 0;
adjtimex(&tx);
if (ret) {
printf("[FAIL]");
return ksft_exit_fail();
}
printf("[OK]");
return ksft_exit_pass();
}