/* ADJ_FREQ Skew consistency 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 back * and forth and watches for consistency problems. Thus this test requires * that the inconsistency-check tests be present in the same directory it * is run from. * * To build: * $ gcc skew_consistency.c -o skew_consistency -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 <unistd.h> #include <sys/time.h> #include <sys/timex.h> #include <time.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <string.h> #include <sys/wait.h> #include "../kselftest.h" #define NSEC_PER_SEC 1000000000LL int main(int argc, char **argv) { struct timex tx; int ret, ppm; pid_t pid; printf("Running Asynchronous Frequency Changing Tests...\n"); pid = fork(); if (!pid) return system("./inconsistency-check -c 1 -t 600"); ppm = 500; ret = 0; while (pid != waitpid(pid, &ret, WNOHANG)) { ppm = -ppm; tx.modes = ADJ_FREQUENCY; tx.freq = ppm << 16; adjtimex(&tx); usleep(500000); } /* Set things back */ tx.modes = ADJ_FREQUENCY; tx.offset = 0; adjtimex(&tx); if (ret) { printf("[FAILED]\n"); return ksft_exit_fail(); } printf("[OK]\n"); return ksft_exit_pass(); }