1 /* ADJ_FREQ Skew consistency 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 back 7 * and forth and watches for consistency problems. Thus this test requires 8 * that the inconsistency-check tests be present in the same directory it 9 * is run from. 10 * 11 * To build: 12 * $ gcc skew_consistency.c -o skew_consistency -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 <unistd.h> 29 #include <sys/time.h> 30 #include <sys/timex.h> 31 #include <time.h> 32 #include <sys/types.h> 33 #include <sys/stat.h> 34 #include <fcntl.h> 35 #include <string.h> 36 #include <sys/wait.h> 37 #include "../kselftest.h" 38 main(int argc,char ** argv)39int main(int argc, char **argv) 40 { 41 struct timex tx; 42 int ret, ppm; 43 pid_t pid; 44 45 46 printf("Running Asynchronous Frequency Changing Tests...\n"); 47 48 pid = fork(); 49 if (!pid) 50 return system("./inconsistency-check -c 1 -t 600"); 51 52 ppm = 500; 53 ret = 0; 54 55 while (pid != waitpid(pid, &ret, WNOHANG)) { 56 ppm = -ppm; 57 tx.modes = ADJ_FREQUENCY; 58 tx.freq = ppm << 16; 59 adjtimex(&tx); 60 usleep(500000); 61 } 62 63 /* Set things back */ 64 tx.modes = ADJ_FREQUENCY; 65 tx.offset = 0; 66 adjtimex(&tx); 67 68 69 if (ret) { 70 printf("[FAILED]\n"); 71 ksft_exit_fail(); 72 } 73 printf("[OK]\n"); 74 ksft_exit_pass(); 75 } 76