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 39 #define NSEC_PER_SEC 1000000000LL 40 41 int main(int argc, char **argv) 42 { 43 struct timex tx; 44 int ret, ppm; 45 pid_t pid; 46 47 48 printf("Running Asynchronous Frequency Changing Tests...\n"); 49 50 pid = fork(); 51 if (!pid) 52 return system("./inconsistency-check -c 1 -t 600"); 53 54 ppm = 500; 55 ret = 0; 56 57 while (pid != waitpid(pid, &ret, WNOHANG)) { 58 ppm = -ppm; 59 tx.modes = ADJ_FREQUENCY; 60 tx.freq = ppm << 16; 61 adjtimex(&tx); 62 usleep(500000); 63 } 64 65 /* Set things back */ 66 tx.modes = ADJ_FREQUENCY; 67 tx.offset = 0; 68 adjtimex(&tx); 69 70 71 if (ret) { 72 printf("[FAILED]\n"); 73 return ksft_exit_fail(); 74 } 75 printf("[OK]\n"); 76 return ksft_exit_pass(); 77 } 78