Attachment 597663 Details for Bug 836803 – Current upstream test for hrtimer expiration

Current upstream test for hrtimer expiration

leap-a-day.c (text/plain), 5.11 KB, created by Prarit Bhargava on 2012-07-11 20:13:12 UTC

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Creator: Prarit Bhargava

Created: 2012-07-11 20:13:12 UTC

Size: 5.11 KB

patch

obsolete

>/* Leap second stress test
> *              by: john stultz (johnstul@us.ibm.com)
> *              (C) Copyright IBM 2012
> *              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]
> *
> *  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.
> *
> *  Other notes: Disabling NTP prior to running this is advised, as the two
> *		 may conflict in thier commands to the kernel.
> *
> *  To build:
> *	$ gcc leap-a-day.c -o leap-a-day -lrt
> */
>
>
>
>#include <stdio.h>
>#include <stdlib.h>
>#include <time.h>
>#include <sys/time.h>
>#include <sys/timex.h>
>#include <string.h>
>#include <signal.h>
>
>#define NSEC_PER_SEC 1000000000ULL
>
>/* 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 */
>void clear_time_state(void)
>{
>	struct timex tx;
>	int ret;
>
>	/*
>	 * XXX - The fact we have to call this twice seems
>	 * to point to a slight issue in the kernel's ntp state
>	 * managment. Needs to be investigated further.
>	 */
>
>	tx.modes = ADJ_STATUS;
>	tx.status = STA_PLL;
>	ret = adjtimex(&tx);
>
>	tx.modes = ADJ_STATUS;
>	tx.status = 0;
>	ret = adjtimex(&tx);
>}
>
>/* 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("Note: hrtimer early expiration failure observed.\n");
>	}
>
>}
>
>
>
>int main(int argc, char** argv) 
>{
>	struct timeval tv;
>	struct timex tx;
>	struct timespec ts;
>	int settime = 0;
>	int x;
>
>	signal(SIGINT, handler);
>	signal(SIGKILL, handler);
>	printf("This runs continuously. Press ctrl-c to stop\n");
>
>
>	/* Process arguments */
>	if (argc > 1) {
>		if (!strncmp(argv[1], "-s", 2)) {
>			printf("Setting time to speed up testing\n");
>			settime = 1;
>		} else {
>			printf("Usage: %s [-s]\n", argv[0]);
>			printf("	-s: Set time to right before leap second each iteration\n");
>		}
>	}
>
>	printf("\n");
>	while (1) {
>		int ret;
>		time_t now, next_leap;
>		/* Get the current time */
>		gettimeofday(&tv, NULL);
>
>		/* Calculate the next possible leap second 23:59:60 GMT */
>		tv.tv_sec += 86400 - (tv.tv_sec % 86400);
>		next_leap = ts.tv_sec = tv.tv_sec;
>
>		if (settime) {
>			tv.tv_sec -= 10;
>			settimeofday(&tv, NULL);
>			printf("Setting time to %s", ctime(&ts.tv_sec));
>		}
>
>		/* Reset NTP time state */
>		clear_time_state();
>
>		/* Set the leap second insert flag */
>		tx.modes = ADJ_STATUS;
>		tx.status = STA_INS;
>		ret = adjtimex(&tx);
>		if (ret) {
>			printf("Error: Problem setting STA_INS!: %s\n",
>							time_state_str(ret));
>			return -1;
>		}
>
>		/* Validate STA_INS was set */
>		ret = adjtimex(&tx);
>		if (tx.status != STA_INS) {
>			printf("Error: STA_INS not set!: %s\n",
>							time_state_str(ret));
>			return -1;
>		}
>
>		printf("Scheduling leap second for %s", ctime(&next_leap));
>	
>		/* Wake up 3 seconds before leap */
>		ts.tv_sec -= 3;
>		if (clock_nanosleep(CLOCK_REALTIME, TIMER_ABSTIME, &ts, NULL))
>			printf("Something woke us up, returning to sleep\n");
>
>		/* Validate STA_INS is still set */
>		ret = adjtimex(&tx);
>		if (tx.status != STA_INS) {
>			printf("Something cleared STA_INS, setting it again.\n");
>			tx.modes = ADJ_STATUS;
>			tx.status = STA_INS;
>			ret = adjtimex(&tx);
>		}
>
>		/* Check adjtimex output every half second */
>		now = tx.time.tv_sec;
>		while (now < next_leap+2) {
>			char buf[26];
>			ret = adjtimex(&tx);
>
>			ctime_r(&tx.time.tv_sec, buf);
>			buf[strlen(buf)-1] = 0; /*remove trailing\n */
>
>			printf("%s + %6ld us\t%s\n",
>					buf,
>					tx.time.tv_usec, 
>					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);			
>		}
>
>		/* Note if kernel has known hrtimer failure */
>		test_hrtimer_failure();
>
>		printf("Leap complete\n\n");
>	}
>
>	clear_time_state();
>	return 0;
>}

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