1 /* Leap second stress test
2 * by: John Stultz (john.stultz@linaro.org)
3 * (C) Copyright IBM 2012
4 * (C) Copyright 2013, 2015 Linaro Limited
5 * Licensed under the GPLv2
7 * This test signals the kernel to insert a leap second
8 * every day at midnight GMT. This allows for stessing the
9 * kernel's leap-second behavior, as well as how well applications
10 * handle the leap-second discontinuity.
12 * Usage: leap-a-day [-s] [-i <num>]
15 * -s: Each iteration, set the date to 10 seconds before midnight GMT.
16 * This speeds up the number of leapsecond transitions tested,
17 * but because it calls settimeofday frequently, advancing the
18 * time by 24 hours every ~16 seconds, it may cause application
21 * -i: Number of iterations to run (default: infinite)
23 * Other notes: Disabling NTP prior to running this is advised, as the two
24 * may conflict in their commands to the kernel.
27 * $ gcc leap-a-day.c -o leap-a-day -lrt
29 * This program is free software: you can redistribute it and/or modify
30 * it under the terms of the GNU General Public License as published by
31 * the Free Software Foundation, either version 2 of the License, or
32 * (at your option) any later version.
34 * This program is distributed in the hope that it will be useful,
35 * but WITHOUT ANY WARRANTY; without even the implied warranty of
36 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
37 * GNU General Public License for more details.
46 #include <sys/timex.h>
51 #include "../kselftest.h"
53 static inline int ksft_exit_pass(void)
57 static inline int ksft_exit_fail(void)
63 #define NSEC_PER_SEC 1000000000ULL
66 /* returns 1 if a <= b, 0 otherwise */
67 static inline int in_order(struct timespec a, struct timespec b)
69 if (a.tv_sec < b.tv_sec)
71 if (a.tv_sec > b.tv_sec)
73 if (a.tv_nsec > b.tv_nsec)
78 struct timespec timespec_add(struct timespec ts, unsigned long long ns)
81 while (ts.tv_nsec >= NSEC_PER_SEC) {
82 ts.tv_nsec -= NSEC_PER_SEC;
88 char *time_state_str(int state)
91 case TIME_OK: return "TIME_OK";
92 case TIME_INS: return "TIME_INS";
93 case TIME_DEL: return "TIME_DEL";
94 case TIME_OOP: return "TIME_OOP";
95 case TIME_WAIT: return "TIME_WAIT";
96 case TIME_BAD: return "TIME_BAD";
101 /* clear NTP time_status & time_state */
102 int clear_time_state(void)
108 * We have to call adjtime twice here, as kernels
109 * prior to 6b1859dba01c7 (included in 3.5 and
110 * -stable), had an issue with the state machine
111 * and wouldn't clear the STA_INS/DEL flag directly.
113 tx.modes = ADJ_STATUS;
117 /* Clear maxerror, as it can cause UNSYNC to be set */
118 tx.modes = ADJ_MAXERROR;
122 /* Clear the status */
123 tx.modes = ADJ_STATUS;
130 /* Make sure we cleanup on ctrl-c */
131 void handler(int unused)
137 /* Test for known hrtimer failure */
138 void test_hrtimer_failure(void)
140 struct timespec now, target;
142 clock_gettime(CLOCK_REALTIME, &now);
143 target = timespec_add(now, NSEC_PER_SEC/2);
144 clock_nanosleep(CLOCK_REALTIME, TIMER_ABSTIME, &target, NULL);
145 clock_gettime(CLOCK_REALTIME, &now);
147 if (!in_order(target, now))
148 printf("ERROR: hrtimer early expiration failure observed.\n");
151 int main(int argc, char **argv)
159 /* Process arguments */
160 while ((opt = getopt(argc, argv, "sti:")) != -1) {
163 printf("Setting time to speed up testing\n");
167 iterations = atoi(optarg);
173 printf("Usage: %s [-s] [-i <iterations>]\n", argv[0]);
174 printf(" -s: Set time to right before leap second each iteration\n");
175 printf(" -i: Number of iterations\n");
176 printf(" -t: Print TAI time\n");
181 /* Make sure TAI support is present if -t was used */
185 if (clock_gettime(CLOCK_TAI, &ts)) {
186 printf("System doesn't support CLOCK_TAI\n");
191 signal(SIGINT, handler);
192 signal(SIGKILL, handler);
195 printf("This runs continuously. Press ctrl-c to stop\n");
197 printf("Running for %i iterations. Press ctrl-c to stop\n", iterations);
204 time_t now, next_leap;
206 /* Get the current time */
207 clock_gettime(CLOCK_REALTIME, &ts);
209 /* Calculate the next possible leap second 23:59:60 GMT */
210 next_leap = ts.tv_sec;
211 next_leap += 86400 - (next_leap % 86400);
216 tv.tv_sec = next_leap - 10;
218 settimeofday(&tv, NULL);
219 printf("Setting time to %s", ctime(&tv.tv_sec));
222 /* Reset NTP time state */
225 /* Set the leap second insert flag */
226 tx.modes = ADJ_STATUS;
233 printf("Error: Problem setting STA_INS/STA_DEL!: %s\n",
234 time_state_str(ret));
235 return ksft_exit_fail();
238 /* Validate STA_INS was set */
241 if (tx.status != STA_INS && tx.status != STA_DEL) {
242 printf("Error: STA_INS/STA_DEL not set!: %s\n",
243 time_state_str(ret));
244 return ksft_exit_fail();
248 printf("Using TAI time,"
249 " no inconsistencies should be seen!\n");
252 printf("Scheduling leap second for %s", ctime(&next_leap));
254 /* Wake up 3 seconds before leap */
255 ts.tv_sec = next_leap - 3;
258 while (clock_nanosleep(CLOCK_REALTIME, TIMER_ABSTIME, &ts, NULL))
259 printf("Something woke us up, returning to sleep\n");
261 /* Validate STA_INS is still set */
264 if (tx.status != STA_INS && tx.status != STA_DEL) {
265 printf("Something cleared STA_INS/STA_DEL, setting it again.\n");
266 tx.modes = ADJ_STATUS;
274 /* Check adjtimex output every half second */
275 now = tx.time.tv_sec;
276 while (now < next_leap + 2) {
284 clock_gettime(CLOCK_TAI, &tai);
285 printf("%ld sec, %9ld ns\t%s\n",
288 time_state_str(ret));
290 ctime_r(&tx.time.tv_sec, buf);
291 buf[strlen(buf)-1] = 0; /*remove trailing\n */
293 printf("%s + %6ld us (%i)\t%s\n",
297 time_state_str(ret));
299 now = tx.time.tv_sec;
300 /* Sleep for another half second */
302 ts.tv_nsec = NSEC_PER_SEC / 2;
303 clock_nanosleep(CLOCK_MONOTONIC, 0, &ts, NULL);
305 /* Switch to using other mode */
308 /* Note if kernel has known hrtimer failure */
309 test_hrtimer_failure();
311 printf("Leap complete\n\n");
313 if ((iterations != -1) && !(--iterations))
318 return ksft_exit_pass();