From 1416270f4a1ae83ea84156ceba19a66a8f88be1f Mon Sep 17 00:00:00 2001 From: John Stultz Date: Tue, 29 May 2018 19:12:18 -0700 Subject: selftest: timers: Tweak raw_skew to SKIP when ADJ_OFFSET/other clock adjustments are in progress In the past we've warned when ADJ_OFFSET was in progress, usually caused by ntpd or some other time adjusting daemon running in non steady sate, which can cause the skew calculations to be incorrect. Thus, this patch checks to see if the clock was being adjusted when we fail so that we don't cause false negatives. Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Miroslav Lichvar Cc: Richard Cochran Cc: Prarit Bhargava Cc: Stephen Boyd Cc: Shuah Khan Cc: linux-kselftest@vger.kernel.org Suggested-by: Miroslav Lichvar Signed-off-by: John Stultz --- v2: Widened the checks to look for other clock adjustments that could happen, as suggested by Miroslav v3: Fixed up commit message --- tools/testing/selftests/timers/raw_skew.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'tools/testing/selftests') diff --git a/tools/testing/selftests/timers/raw_skew.c b/tools/testing/selftests/timers/raw_skew.c index ca6cd146aafe..dcf73c5dab6e 100644 --- a/tools/testing/selftests/timers/raw_skew.c +++ b/tools/testing/selftests/timers/raw_skew.c @@ -134,6 +134,11 @@ int main(int argv, char **argc) printf(" %lld.%i(act)", ppm/1000, abs((int)(ppm%1000))); if (llabs(eppm - ppm) > 1000) { + if (tx1.offset || tx2.offset || + tx1.freq != tx2.freq || tx1.tick != tx2.tick) { + printf(" [SKIP]\n"); + return ksft_exit_skip("The clock was adjusted externally. Shutdown NTPd or other time sync daemons\n"); + } printf(" [FAILED]\n"); return ksft_exit_fail(); } -- cgit v1.2.3-59-g8ed1b