Re: [PATCH 2/2][RFC] kselftest: timers: Add adjtick test to validate adjtimex() tick adjustments

[John Stultz]

On Wed, Sep 9, 2015 at 1:32 AM, Miroslav Lichvar <mlichvar@xxxxxxxxxx> wrote:
> On Tue, Sep 08, 2015 at 10:57:06PM -0700, John Stultz 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.
>
> Great!
>
>> +     ppm = ((long long)tickval * MILLION)/10000 - MILLION;
>
> I think this needs to be based on sysconf(_SC_CLK_TCK) or similar,
> since the user-space HZ is not 100 on all archs.

Good point. Fixing that up now. Will resend in a bit.

thanks
-john
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