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    SubjectRe: [RFC] New timeofday proposal (v.A1)
    On 8 Dec 2004 at 11:58, john stultz wrote:

    [...]
    > behavior of adjtimex(). We need to be able to implement the following
    > adjustments within a single tick:
    >
    > 1. Adjust the frequency by 500ppm for 10usecs

    What do you mean by "for 10usecs"?

    > 2. After that adjust the frequency by 30ppm for the rest of the tick.

    I'm not sure what you are taling about: plain old adjtime() or the NTP kernel
    interface?

    [...]
    > I may have asked this before, but w/ 32 bit mult and shifts, how
    > granular can these adjustments be?

    Independent of any bits, the precision should be up to 1ns for reading and setting
    the clock, and as a consequence you might provide internal fractional nanoseconds
    (if you want to have a truly stable nanosecond clock model). If we get this right,
    there will be peace in this area until the wires in a PC are significantly shorter
    than 30cm (I think this is how far the light goes in 1ns). ;-)

    >
    > Also additional complications arise when we have multiple things (like
    > cpufreq) playing with the timesource frequency values as well.

    I see a bug difference between precise time keeping and "playing" with
    timesources.

    Regards,
    Ulrich

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