DragonFly kernel List (threaded) for 2003-07
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Re: just curious
I think implementing support for multiple requests is much easier than
exporting it under a normal API.
Well, for "a normal API" read "a traditional UNIX API". I don't see any
reason the Dragonfly API couldn't be used directly by applications.
However, there
isn't really any support on clients for say stat file x - if it has
changed read bytes i - j and then write z to byte k.
Ah, this is the same problem, basically, as out-of-order scheduling at
the processor "microcode" level. If there's a dependency in the
scheduling you get a bubble in the pipeline: in this case the read and
write are dependant on the stat, so they can execute in parallel but
they can't start until the stat completes... *or* you can schedule the
read anyway and throw the data away if the stat fails... and the optimum
strategy is different depending on the relative cost of the operations
and how close to the critical path they are.
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