[PATCH 13/19] selftests/timers: Add skew_consistency test from the timetests suite

From: John Stultz
Date: Mon Mar 02 2015 - 16:12:19 EST


This change adds the skew_consistency test, which twists the
ADJ_FREQUENCY knob back and forth and watches for timekeeping
inconsistencies.

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 | 3 +-
tools/testing/selftests/timers/skew_consistency.c | 89 +++++++++++++++++++++++
2 files changed, 91 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/timers/skew_consistency.c

diff --git a/tools/testing/selftests/timers/Makefile b/tools/testing/selftests/timers/Makefile
index 55b74cc..4b6b5c3 100644
--- a/tools/testing/selftests/timers/Makefile
+++ b/tools/testing/selftests/timers/Makefile
@@ -4,7 +4,7 @@ CFLAGS += -O3 -Wl,-no-as-needed -Wall $(BUILD_FLAGS)
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
+ alarmtimer-suspend change_skew skew_consistency

all: ${bins}

@@ -27,6 +27,7 @@ run_destructive_tests: run_tests
./alarmtimer-suspend
./valid-adjtimex
./change_skew
+ ./skew_consistency

clean:
rm -f ${bins}
diff --git a/tools/testing/selftests/timers/skew_consistency.c b/tools/testing/selftests/timers/skew_consistency.c
new file mode 100644
index 0000000..5562f84
--- /dev/null
+++ b/tools/testing/selftests/timers/skew_consistency.c
@@ -0,0 +1,89 @@
+/* ADJ_FREQ Skew consistency test
+ * by: john stultz (johnstul@xxxxxxxxxx)
+ * (C) Copyright IBM 2012
+ * Licensed under the GPLv2
+ *
+ * NOTE: This is a meta-test which cranks the ADJ_FREQ knob back
+ * and forth and watches for consistency problems. Thus this test requires
+ * that the inconsistency-check tests be present in the same directory it
+ * is run from.
+ *
+ * To build:
+ * $ gcc skew_consistency.c -o skew_consistency -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 <unistd.h>
+#include <sys/time.h>
+#include <sys/timex.h>
+#include <time.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/wait.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 1000000000LL
+
+int main(int argv, char **argc)
+{
+ struct timex tx;
+ int ret, ppm;
+ pid_t pid;
+
+
+ printf("Running Asyncrhonous Frequency Changing Tests...\n");
+
+ pid = fork();
+ if (!pid)
+ return system("./inconsistency-check -c 1 -t 600");
+
+ ppm = 500;
+ ret = 0;
+
+ while (pid != waitpid(pid, &ret, WNOHANG)) {
+ ppm = -ppm;
+ tx.modes = ADJ_FREQUENCY;
+ tx.freq = ppm << 16;
+ adjtimex(&tx);
+ usleep(500000);
+ }
+
+ /* Set things back */
+ tx.modes = ADJ_FREQUENCY;
+ tx.offset = 0;
+ adjtimex(&tx);
+
+
+ if (ret) {
+ printf("[FAILED]\n");
+ return ksft_exit_fail();
+ }
+ printf("[OK]\n");
+ return ksft_exit_pass();
+}
--
1.9.1

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