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SubjectRe: [PATCH] time: Improve documentation of timekeeeping_adjust()
On Thu, Oct 27, 2011 at 06:12:42PM -0700, John Stultz wrote:
> diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
> index a5846a8..de8737e 100644
> --- a/kernel/time/timekeeping.c
> +++ b/kernel/time/timekeeping.c
> @@ -802,14 +802,44 @@ static void timekeeping_adjust(s64 offset)
> s64 error, interval = timekeeper.cycle_interval;
> int adj;
>
> + /*
> + * The point of this is to check if the error is greater then half
> + * an interval.
> + *
> + * First we shift it down from NTP_SHIFT to clocksource->shifted nsecs.
> + *
> + * Note we subtract one in the shift, so that error is really error*2.
> + * This "saves" dividing(shifting) intererval twice, but keeps the
> + * (error > interval) comparision as still measuring if error is
> + * larger then half an interval.
> + *
> + * Note: It does not "save" on aggrivation when reading the code.

... or on "aggravation" either :)

Thanks,
Richard


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