[tip: timers/core] selftests/timers: Improve skew_consistency by testing with other clockids

[tip-bot2 for John Stultz]

The following commit has been merged into the timers/core branch of tip:

Commit-ID:     e40d3709c0225f5f681fd300f65a65ac63b10f83
Gitweb:        https://git.kernel.org/tip/e40d3709c0225f5f681fd300f65a65ac63b10f83
Author:        John Stultz <jstultz@xxxxxxxxxx>
AuthorDate:    Thu, 20 Mar 2025 13:03:01 -07:00
Committer:     Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Fri, 21 Mar 2025 19:16:18 +01:00

selftests/timers: Improve skew_consistency by testing with other clockids

Lei Chen reported a bug with CLOCK_MONOTONIC_COARSE having inconsistencies
when NTP is adjusting the clock frequency.

This has gone seemingly undetected for ~15 years, illustrating a clear gap
in our testing.

The skew_consistency test is intended to catch this sort of problem, but
was focused on only evaluating CLOCK_MONOTONIC, and thus missed the problem
on CLOCK_MONOTONIC_COARSE.

So adjust the test to run with all clockids for 60 seconds each instead of
10 minutes with just CLOCK_MONOTONIC.

Reported-by: Lei Chen <lei.chen@xxxxxxxxxx>
Signed-off-by: John Stultz <jstultz@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/all/20250320200306.1712599-2-jstultz@xxxxxxxxxx
Closes: https://lore.kernel.org/lkml/20250310030004.3705801-1-lei.chen@xxxxxxxxxx/
---
 tools/testing/selftests/timers/skew_consistency.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/timers/skew_consistency.c b/tools/testing/selftests/timers/skew_consistency.c
index 8345014..46c391d 100644
--- a/tools/testing/selftests/timers/skew_consistency.c
+++ b/tools/testing/selftests/timers/skew_consistency.c
@@ -47,7 +47,7 @@ int main(int argc, char **argv)
 
 	pid = fork();
 	if (!pid)
-		return system("./inconsistency-check -c 1 -t 600");
+		return system("./inconsistency-check -t 60");
 
 	ppm = 500;
 	ret = 0;