diff options
Diffstat (limited to 'tools/testing/selftests/timers/leap-a-day.c')
-rw-r--r-- | tools/testing/selftests/timers/leap-a-day.c | 319 |
1 files changed, 319 insertions, 0 deletions
diff --git a/tools/testing/selftests/timers/leap-a-day.c b/tools/testing/selftests/timers/leap-a-day.c new file mode 100644 index 000000000000..b8272e6c4b3b --- /dev/null +++ b/tools/testing/selftests/timers/leap-a-day.c @@ -0,0 +1,319 @@ +/* Leap second stress test + * by: John Stultz (john.stultz@linaro.org) + * (C) Copyright IBM 2012 + * (C) Copyright 2013, 2015 Linaro Limited + * Licensed under the GPLv2 + * + * This test signals the kernel to insert a leap second + * every day at midnight GMT. This allows for stessing the + * kernel's leap-second behavior, as well as how well applications + * handle the leap-second discontinuity. + * + * Usage: leap-a-day [-s] [-i <num>] + * + * Options: + * -s: Each iteration, set the date to 10 seconds before midnight GMT. + * This speeds up the number of leapsecond transitions tested, + * but because it calls settimeofday frequently, advancing the + * time by 24 hours every ~16 seconds, it may cause application + * disruption. + * + * -i: Number of iterations to run (default: infinite) + * + * Other notes: Disabling NTP prior to running this is advised, as the two + * may conflict in their commands to the kernel. + * + * To build: + * $ gcc leap-a-day.c -o leap-a-day -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 <time.h> +#include <sys/time.h> +#include <sys/timex.h> +#include <string.h> +#include <signal.h> +#include <unistd.h> +#ifdef KTEST +#include "../kselftest.h" +#else +static inline int ksft_exit_pass(void) +{ + exit(0); +} +static inline int ksft_exit_fail(void) +{ + exit(1); +} +#endif + +#define NSEC_PER_SEC 1000000000ULL +#define CLOCK_TAI 11 + +/* returns 1 if a <= b, 0 otherwise */ +static inline int in_order(struct timespec a, struct timespec b) +{ + if (a.tv_sec < b.tv_sec) + return 1; + if (a.tv_sec > b.tv_sec) + return 0; + if (a.tv_nsec > b.tv_nsec) + return 0; + return 1; +} + +struct timespec timespec_add(struct timespec ts, unsigned long long ns) +{ + ts.tv_nsec += ns; + while (ts.tv_nsec >= NSEC_PER_SEC) { + ts.tv_nsec -= NSEC_PER_SEC; + ts.tv_sec++; + } + return ts; +} + +char *time_state_str(int state) +{ + switch (state) { + case TIME_OK: return "TIME_OK"; + case TIME_INS: return "TIME_INS"; + case TIME_DEL: return "TIME_DEL"; + case TIME_OOP: return "TIME_OOP"; + case TIME_WAIT: return "TIME_WAIT"; + case TIME_BAD: return "TIME_BAD"; + } + return "ERROR"; +} + +/* clear NTP time_status & time_state */ +int clear_time_state(void) +{ + struct timex tx; + int ret; + + /* + * We have to call adjtime twice here, as kernels + * prior to 6b1859dba01c7 (included in 3.5 and + * -stable), had an issue with the state machine + * and wouldn't clear the STA_INS/DEL flag directly. + */ + tx.modes = ADJ_STATUS; + tx.status = STA_PLL; + ret = adjtimex(&tx); + + /* Clear maxerror, as it can cause UNSYNC to be set */ + tx.modes = ADJ_MAXERROR; + tx.maxerror = 0; + ret = adjtimex(&tx); + + /* Clear the status */ + tx.modes = ADJ_STATUS; + tx.status = 0; + ret = adjtimex(&tx); + + return ret; +} + +/* Make sure we cleanup on ctrl-c */ +void handler(int unused) +{ + clear_time_state(); + exit(0); +} + +/* Test for known hrtimer failure */ +void test_hrtimer_failure(void) +{ + struct timespec now, target; + + clock_gettime(CLOCK_REALTIME, &now); + target = timespec_add(now, NSEC_PER_SEC/2); + clock_nanosleep(CLOCK_REALTIME, TIMER_ABSTIME, &target, NULL); + clock_gettime(CLOCK_REALTIME, &now); + + if (!in_order(target, now)) + printf("ERROR: hrtimer early expiration failure observed.\n"); +} + +int main(int argc, char **argv) +{ + int settime = 0; + int tai_time = 0; + int insert = 1; + int iterations = -1; + int opt; + + /* Process arguments */ + while ((opt = getopt(argc, argv, "sti:")) != -1) { + switch (opt) { + case 's': + printf("Setting time to speed up testing\n"); + settime = 1; + break; + case 'i': + iterations = atoi(optarg); + break; + case 't': + tai_time = 1; + break; + default: + printf("Usage: %s [-s] [-i <iterations>]\n", argv[0]); + printf(" -s: Set time to right before leap second each iteration\n"); + printf(" -i: Number of iterations\n"); + printf(" -t: Print TAI time\n"); + exit(-1); + } + } + + /* Make sure TAI support is present if -t was used */ + if (tai_time) { + struct timespec ts; + + if (clock_gettime(CLOCK_TAI, &ts)) { + printf("System doesn't support CLOCK_TAI\n"); + ksft_exit_fail(); + } + } + + signal(SIGINT, handler); + signal(SIGKILL, handler); + + if (iterations < 0) + printf("This runs continuously. Press ctrl-c to stop\n"); + else + printf("Running for %i iterations. Press ctrl-c to stop\n", iterations); + + printf("\n"); + while (1) { + int ret; + struct timespec ts; + struct timex tx; + time_t now, next_leap; + + /* Get the current time */ + clock_gettime(CLOCK_REALTIME, &ts); + + /* Calculate the next possible leap second 23:59:60 GMT */ + next_leap = ts.tv_sec; + next_leap += 86400 - (next_leap % 86400); + + if (settime) { + struct timeval tv; + + tv.tv_sec = next_leap - 10; + tv.tv_usec = 0; + settimeofday(&tv, NULL); + printf("Setting time to %s", ctime(&tv.tv_sec)); + } + + /* Reset NTP time state */ + clear_time_state(); + + /* Set the leap second insert flag */ + tx.modes = ADJ_STATUS; + if (insert) + tx.status = STA_INS; + else + tx.status = STA_DEL; + ret = adjtimex(&tx); + if (ret < 0) { + printf("Error: Problem setting STA_INS/STA_DEL!: %s\n", + time_state_str(ret)); + return ksft_exit_fail(); + } + + /* Validate STA_INS was set */ + tx.modes = 0; + ret = adjtimex(&tx); + if (tx.status != STA_INS && tx.status != STA_DEL) { + printf("Error: STA_INS/STA_DEL not set!: %s\n", + time_state_str(ret)); + return ksft_exit_fail(); + } + + if (tai_time) { + printf("Using TAI time," + " no inconsistencies should be seen!\n"); + } + + printf("Scheduling leap second for %s", ctime(&next_leap)); + + /* Wake up 3 seconds before leap */ + ts.tv_sec = next_leap - 3; + ts.tv_nsec = 0; + + while (clock_nanosleep(CLOCK_REALTIME, TIMER_ABSTIME, &ts, NULL)) + printf("Something woke us up, returning to sleep\n"); + + /* Validate STA_INS is still set */ + tx.modes = 0; + ret = adjtimex(&tx); + if (tx.status != STA_INS && tx.status != STA_DEL) { + printf("Something cleared STA_INS/STA_DEL, setting it again.\n"); + tx.modes = ADJ_STATUS; + if (insert) + tx.status = STA_INS; + else + tx.status = STA_DEL; + ret = adjtimex(&tx); + } + + /* Check adjtimex output every half second */ + now = tx.time.tv_sec; + while (now < next_leap + 2) { + char buf[26]; + struct timespec tai; + + tx.modes = 0; + ret = adjtimex(&tx); + + if (tai_time) { + clock_gettime(CLOCK_TAI, &tai); + printf("%ld sec, %9ld ns\t%s\n", + tai.tv_sec, + tai.tv_nsec, + time_state_str(ret)); + } else { + ctime_r(&tx.time.tv_sec, buf); + buf[strlen(buf)-1] = 0; /*remove trailing\n */ + + printf("%s + %6ld us (%i)\t%s\n", + buf, + tx.time.tv_usec, + tx.tai, + time_state_str(ret)); + } + now = tx.time.tv_sec; + /* Sleep for another half second */ + ts.tv_sec = 0; + ts.tv_nsec = NSEC_PER_SEC / 2; + clock_nanosleep(CLOCK_MONOTONIC, 0, &ts, NULL); + } + /* Switch to using other mode */ + insert = !insert; + + /* Note if kernel has known hrtimer failure */ + test_hrtimer_failure(); + + printf("Leap complete\n\n"); + + if ((iterations != -1) && !(--iterations)) + break; + } + + clear_time_state(); + return ksft_exit_pass(); +} |