Re: [PARPORT] How can cpu use by the parport be limited? (question from new cpia driver maintainer)

From: Alan Cox (
Date: Fri Dec 27 2002 - 19:37:20 EST

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    On Fri, 2002-12-27 at 21:46, Duncan Haldane wrote
    > Does anyone has any suggestions for some way I can get my kernel-mode
    > implementation to behave nicely by not grabbing all available cpu
    > resources while processing the nibbles as they dribble across
    > the parport interface, (IF that is what is causing the problem, but maybe
    > it's some other issue? I have no experience with this, as I am a parport
    > novice; what else could be causing it --- some lock?).

    For 2.4 check current->need_resched, 2.5 ditto but kernel pre-empt also
    helps you out

    > Is this an issue of kernel-non-premptability ?(I'd like to fix it for 2.4.x
    > (>2.4.20) kernels, if possible).

    Yes - and current->need_resched says "would have rescheduled you .." so
    you can use that to call schedule() in loops.

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