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-rw-r--r--kernel/tools/testing/selftests/timers/change_skew.c107
1 files changed, 107 insertions, 0 deletions
diff --git a/kernel/tools/testing/selftests/timers/change_skew.c b/kernel/tools/testing/selftests/timers/change_skew.c
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+++ b/kernel/tools/testing/selftests/timers/change_skew.c
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+/* ADJ_FREQ Skew change 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 and
+ * then uses other tests to detect problems. Thus this test requires
+ * that the raw_skew, inconsistency-check and nanosleep tests be
+ * present in the same directory it is run from.
+ *
+ * To build:
+ * $ gcc change_skew.c -o change_skew -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 <sys/time.h>
+#include <sys/timex.h>
+#include <time.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 change_skew_test(int ppm)
+{
+ struct timex tx;
+ int ret;
+
+ tx.modes = ADJ_FREQUENCY;
+ tx.freq = ppm << 16;
+
+ ret = adjtimex(&tx);
+ if (ret < 0) {
+ printf("Error adjusting freq\n");
+ return ret;
+ }
+
+ ret = system("./raw_skew");
+ ret |= system("./inconsistency-check");
+ ret |= system("./nanosleep");
+
+ return ret;
+}
+
+
+int main(int argv, char **argc)
+{
+ struct timex tx;
+ int i, ret;
+
+ int ppm[5] = {0, 250, 500, -250, -500};
+
+ /* Kill ntpd */
+ ret = system("killall -9 ntpd");
+
+ /* Make sure there's no offset adjustment going on */
+ tx.modes = ADJ_OFFSET;
+ tx.offset = 0;
+ ret = adjtimex(&tx);
+
+ if (ret < 0) {
+ printf("Maybe you're not running as root?\n");
+ return -1;
+ }
+
+ for (i = 0; i < 5; i++) {
+ printf("Using %i ppm adjustment\n", ppm[i]);
+ ret = change_skew_test(ppm[i]);
+ if (ret)
+ break;
+ }
+
+ /* Set things back */
+ tx.modes = ADJ_FREQUENCY;
+ tx.offset = 0;
+ adjtimex(&tx);
+
+ if (ret) {
+ printf("[FAIL]");
+ return ksft_exit_fail();
+ }
+ printf("[OK]");
+ return ksft_exit_pass();
+}