[PATCH 15/19] selftests/timers: Add leap-a-day test from timetest suite

From: John Stultz
Date: Wed Feb 25 2015 - 17:34:23 EST


This change adds the leap-a-day test which sets STA_INS and
STA_DEL each day to trigger leapseconds each day. It also
has a mode to jump the time to right before the end of the
day each iteration.

Cc: Shuah Khan <shuahkh@xxxxxxxxxxxxxxx>
Cc: Prarit Bhargava <prarit@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Richard Cochran <richardcochran@xxxxxxxxx>
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
---
tools/testing/selftests/timers/Makefile | 2 +
tools/testing/selftests/timers/leap-a-day.c | 306 ++++++++++++++++++++++++++++
2 files changed, 308 insertions(+)
create mode 100644 tools/testing/selftests/timers/leap-a-day.c

diff --git a/tools/testing/selftests/timers/Makefile b/tools/testing/selftests/timers/Makefile
index d50a1ef..6acc920 100644
--- a/tools/testing/selftests/timers/Makefile
+++ b/tools/testing/selftests/timers/Makefile
@@ -3,6 +3,7 @@ LDFLAGS += -lrt -lpthread
bins = posix_timers nanosleep inconsistency-check nsleep-lat raw_skew \
set-timer-lat threadtest mqueue-lat valid-adjtimex \
alarmtimer-suspend change_skew skew_consistency clocksource-switch \
+ leap-a-day

all: ${bins}

@@ -27,6 +28,7 @@ run_destructive_tests: run_tests
./change_skew
./skew_consistency
./clocksource-switch
+ ./leap-a-day -s -i 10

clean:
rm -f ${bins}
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 0000000..60cef47
--- /dev/null
+++ b/tools/testing/selftests/timers/leap-a-day.c
@@ -0,0 +1,306 @@
+/* Leap second stress test
+ * by: John Stultz (john.stultz@xxxxxxxxxx)
+ * (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 thier 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>
+
+extern char *optarg;
+
+#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 */
+void 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);
+}
+
+/* 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");
+ exit(-1);
+ }
+ }
+
+ 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 -1;
+ }
+
+ /* 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 -1;
+ }
+
+ 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 0;
+}
--
1.9.1

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