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    SubjectRe: [PATCH 1/6] hrtimer: Provide clock_was_set_delayed()

    >> I wish there was a nicer way to do this ... but looking at the code I can't
    >> figure out a better way. (no offense John, it's just the way the code is ;) )
    >
    > Yeah, I had the same discussion with Peter earlier today. There is
    > only a rather limited set of options.
    >
    > 1) Retrigger the timer interrupt vectors on all CPUs - except the one
    > we are running on, but we have no interface for that at the moment
    >
    > 2) Do the nasty __smp_call_function_single() hack
    >
    > Preallocate call_single_data for all cpus and do a
    > __smp_call_function_single() on all online cpus.
    >
    > This can be called from hard interrupt context or irq disabled
    > regions.
    >
    > That would allow to get rid of the whole delay magic all
    > together.
    >
    > Thoughts?
    >

    Both of those options seem like a lot of work for something that happens once
    every 3-4 years, and may not happen ever again[1]. Based on that statement, if
    we're going to modify code I would prefer that it be as lightweight as possible.
    So, in terms of the kernel, option 2 is likely the best way to go rather than
    introducing new code that will be used once every 3-4 years.

    I keep asking the question of why the mechanism of inserting a leap second isn't
    moved into userspace ntpd (or some other appropriate daemon). I suppose there
    is a risk of ntpd being starved out on heavily loaded systems...

    P.

    [1] http://en.wikipedia.org/wiki/Leap_second#Proposal_to_abolish_leap_seconds


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