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    SubjectRe: schedule()
    On Tue, 26 Feb 2002, Richard B. Johnson wrote:

    > On Tue, 26 Feb 2002, Davide Libenzi wrote:
    >
    > > On Tue, 26 Feb 2002, Richard B. Johnson wrote:
    > >
    > > >
    > > >
    > > > I just read on this list that:
    > > >
    > > > while(something)
    > > > {
    > > > current->policy |= SCHED_YIELD;
    > > > schedule();
    > > > }
    > > >
    > > > Will no longer be allowed in a kernel module! If this is true, how
    > > > do I loop, waiting for a bit in a port, without wasting CPU time?
    > > >
    > > > A lot of hardware does not generate interrupts upon a condition,
    > > > there is no CPU activity that could send a wake_up_interruptible()
    > > > to something sleeping.
    > > >
    > > > For instance, I need to write data to a hardware FIFO, one long-word
    > > > at a time, but I can't just write. I have to wait for a bit to be
    > > > set or reset for each and every write. I'm going to be burning a
    > > > lot of CPU cycles if I can't schedule() while the trickle-down-effect
    > > > of the hardware is happening.
    > >
    > > What did it do yield() to you ? Doesn't it work for your case ?
    > >
    > There isn't one in 2.4.x I'll modify my drivers to use YIELD
    > and #define it depending upon version.

    In 2.5 yield() maps to sys_sched_yield(). You can handle it in the same
    way in your includes if version <= 2.4.




    - Davide


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