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Re: nanosleep() for shorted than schedule slice (Johnny Billquist) writes:

>> A tickless kernel wouldn't run callouts from the regular clock interrupt
>> but would use a hires timer to issue interrupts at arbitrary times.
>> The callout API could then be changed to either accept timespec values or
>> just fake a much higher HZ value.

>Right. Not that I believe this have to be tied into tickless, but I 
>suspect it might be easier to do it if we go tickless.

Well, "not using a regular clock interrupt" is what "tickless" means.

>We really should be able to deal with shorter times, even if we have 

That's a contradiction. "ticks" means that timed events are based
on a regular clock interrupt. Of course you can speed up the ticks
(e.g. Alpha uses HZ=1000), but that has other disadvantages.

N.B. going tickless isn't difficult, it's just lots of work as it needs
MD support on all platforms.

                                Michael van Elst
                                "A potential Snark may lurk in every tree."

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