Re: [PATCH v1] tools: timers: fix freq average calculation

[Shuah Khan]

On 7/5/23 21:46, John Stultz wrote:
> On Wed, Jul 5, 2023 at 8:23 PM Minjie Du <duminjie@xxxxxxxx> wrote:
> > Delete a duplicate assignment from this function implementation.
> > The note means ppm is average of the two actual freq samples.
> > But ppm have a duplicate assignment.
> >
> > Signed-off-by: Minjie Du <duminjie@xxxxxxxx>
> > ---
> >   tools/testing/selftests/timers/raw_skew.c | 3 +--
> >   1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/tools/testing/selftests/timers/raw_skew.c b/tools/testing/selftests/timers/raw_skew.c
> > index 5beceeed0..6eba203f9 100644
> > --- a/tools/testing/selftests/timers/raw_skew.c
> > +++ b/tools/testing/selftests/timers/raw_skew.c
> > @@ -129,8 +129,7 @@ int main(int argc, char **argv)
> >          printf("%lld.%i(est)", eppm/1000, abs((int)(eppm%1000)));
> >
> >          /* Avg the two actual freq samples adjtimex gave us */
> > -       ppm = (tx1.freq + tx2.freq) * 1000 / 2;
> > -       ppm = (long long)tx1.freq * 1000;
> > +       ppm = (long long)(tx1.freq + tx2.freq) * 1000 / 2;
>
> Huh. So yeah, I looked back in my own history and this has been there
> forever. I'm guessing I was intending to average the two samples and
> then due to reasons I can't remember decided to just use the first in
> the short-term for some debugging (with the second assignment) and
> committed both.
>
> I think it should be safe, because if the freq values are not the same
> the test will return SKIP, so it's unlikely changing this would cause
> new test failures.
>
> Acked-by: John Stultz <jstultz@xxxxxxxxxx>
>
> Thanks for noticing this and sending this out!
> -john

Applied to linux-kselftest fixes branch for next rc2 or rc3

thanks,
-- Shuah