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-rw-r--r--tools/testing/selftests/timers/skew_consistency.c77
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diff --git a/tools/testing/selftests/timers/skew_consistency.c b/tools/testing/selftests/timers/skew_consistency.c
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+/* ADJ_FREQ Skew consistency test
+ * by: john stultz (johnstul@us.ibm.com)
+ * (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 <string.h>
+#include <sys/wait.h>
+#include "../kselftest.h"
+
+#define NSEC_PER_SEC 1000000000LL
+
+int main(int argv, char **argc)
+{
+ struct timex tx;
+ int ret, ppm;
+ pid_t pid;
+
+
+ printf("Running Asynchronous 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();
+}