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

From: Z F (mail4me9999@yahoo.com)
Date: Fri Dec 27 2002 - 22:27:08 EST

  • Next message: Blaise Gassend: "Re: [PARPORT] How can cpu use by the parport be limited? (question from new cpia driver maintainer)"

    Hello

    May I ask if exectly the same solution will help with the SuperDisk
    parallel port diver?

    It uses huge amounts of CPU time and works much slower than under
    windows.

    The same symptoms, everything freezes during the disk I/O.
    Thanks

    Lazar

    --- Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:
    > 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.
    >
    >
    > -- To unsubscribe, send mail to: linux-parport-request@torque.net --
    > -- with the single word "unsubscribe" in the body of the message. --
    >

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