Re: [PATCH v3] kselftest: timers: Add adjtick test to validate adjtimex() tick adjustments

From: Ingo Molnar
Date: Sat Oct 03 2015 - 03:47:41 EST



* John Stultz <john.stultz@xxxxxxxxxx> wrote:

> Recently an issue was reported that was difficult to detect except
> by tweaking the adjtimex tick value, and noticing how quickly the
> adjustment took to be made:
> https://lkml.org/lkml/2015/9/1/488
>
> Thus this patch introduces a new test which manipulates the adjtimex
> tick value and validates the results are what we expect.

So I tried to run this:

triton:~/tip/tools/testing/selftests/timers> ./adjtick
systick: 10000
Estimating tick (act: 9000 usec, -100000 ppm): 10000 usec, 1 ppmWARNING: Unexpected adjtimex return values, make sure ntpd is not running. triton:~/tip/tools/testing/selftests/timers>

note the weird placement of the warning, and there's also no newline at the end.

It would also be nice to print out roughly how long the test will take - since it
runs longer than 1-2 seconds.

Thanks,

Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/