[SRU,B] selftest: timers: Tweak raw_skew to SKIP when ADJ_OFFSET/other clock adjustments are in progress

Message ID 20190201174526.16454-1-dan.streetman@canonical.com
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  • [SRU,B] selftest: timers: Tweak raw_skew to SKIP when ADJ_OFFSET/other clock adjustments are in progress
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Commit Message

Dan Streetman Feb. 1, 2019, 5:45 p.m.
From: John Stultz <john.stultz@linaro.org>

BugLink: https://bugs.launchpad.net/bugs/1811194

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 <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org
Suggested-by: Miroslav Lichvar <mlichvar@redhat.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
v2: Widened the checks to look for other clock adjustments that
    could happen, as suggested by Miroslav
v3: Fixed up commit message

Signed-off-by: Dan Streetman <ddstreet@canonical.com>
(cherry-picked from upstream 1416270f4a1ae83ea84156ceba19a66a8f88be1f)
---
 tools/testing/selftests/timers/raw_skew.c | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Stefan Bader Feb. 7, 2019, 8:18 a.m. | #1
On 01.02.19 18:45, Dan Streetman wrote:
> From: John Stultz <john.stultz@linaro.org>
> 
> BugLink: https://bugs.launchpad.net/bugs/1811194
> 
> 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 <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@kernel.org>
> Cc: Miroslav Lichvar <mlichvar@redhat.com>
> Cc: Richard Cochran <richardcochran@gmail.com>
> Cc: Prarit Bhargava <prarit@redhat.com>
> Cc: Stephen Boyd <sboyd@kernel.org>
> Cc: Shuah Khan <shuah@kernel.org>
> Cc: linux-kselftest@vger.kernel.org
> Suggested-by: Miroslav Lichvar <mlichvar@redhat.com>
> Signed-off-by: John Stultz <john.stultz@linaro.org>
> ---
> v2: Widened the checks to look for other clock adjustments that
>     could happen, as suggested by Miroslav
> v3: Fixed up commit message
> 
> Signed-off-by: Dan Streetman <ddstreet@canonical.com>
> (cherry-picked from upstream 1416270f4a1ae83ea84156ceba19a66a8f88be1f)
Acked-by: Stefan Bader <stefan.bader@canonical.com>
> ---
>  tools/testing/selftests/timers/raw_skew.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> 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();
>  	}
>

Patch

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();
 	}