1 /* Clocksource change test
2 * by: john stultz (johnstul@us.ibm.com)
3 * (C) Copyright IBM 2012
4 * Licensed under the GPLv2
6 * NOTE: This is a meta-test which quickly changes the clocksourc and
7 * then uses other tests to detect problems. Thus this test requires
8 * that the inconsistency-check and nanosleep tests be present in the
9 * same directory it is run from.
12 * $ gcc clocksource-switch.c -o clocksource-switch -lrt
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.
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.
30 #include <sys/timex.h>
32 #include <sys/types.h>
37 #include "../kselftest.h"
40 int get_clocksources(char list[][30])
47 fd = open("/sys/devices/system/clocksource/clocksource0/available_clocksource", O_RDONLY);
49 size = read(fd, buf, 512);
53 for (i = 0; i < 10; i++)
58 while (head - buf < size) {
59 /* Find the next space */
60 for (tmp = head; *tmp != ' '; tmp++) {
67 strcpy(list[i], head);
75 int get_cur_clocksource(char *buf, size_t size)
79 fd = open("/sys/devices/system/clocksource/clocksource0/current_clocksource", O_RDONLY);
81 size = read(fd, buf, size);
86 int change_clocksource(char *clocksource)
91 fd = open("/sys/devices/system/clocksource/clocksource0/current_clocksource", O_WRONLY);
96 size = write(fd, clocksource, strlen(clocksource));
106 int run_tests(int secs)
111 sprintf(buf, "./inconsistency-check -t %i", secs);
115 ret = system("./nanosleep");
120 char clocksource_list[10][30];
122 int main(int argv, char **argc)
125 int count, i, status;
128 get_cur_clocksource(orig_clk, 512);
130 count = get_clocksources(clocksource_list);
132 if (change_clocksource(clocksource_list[0])) {
133 printf("Error: You probably need to run this as root\n");
137 /* Check everything is sane before we start switching asyncrhonously */
138 for (i = 0; i < count; i++) {
139 printf("Validating clocksource %s\n", clocksource_list[i]);
140 if (change_clocksource(clocksource_list[i])) {
151 printf("Running Asynchronous Switching Tests...\n");
154 return run_tests(60);
156 while (pid != waitpid(pid, &status, WNOHANG))
157 for (i = 0; i < count; i++)
158 if (change_clocksource(clocksource_list[i])) {
163 change_clocksource(orig_clk);
166 return ksft_exit_fail();
167 return ksft_exit_pass();