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    SubjectRe: looking for info on kernel_thread
    On Tue, Apr 13, 1999 at 05:54:04PM +0100, Stephen C. Tweedie wrote:
    > The are _non_ preemptable, just like any other process. The general
    > rule is that we never, ever preempt a process which is running in kernel
    > mode. That means that normal user processes do not get preempted in the
    > middle of a system call, for example. It also means that kernel
    > threads, which run entirely within kernel mode, are automatically
    > protected against preemption by the scheduler.
    > Kernel threads are still allowed to be rescheduled, but only
    > voluntarily: if they sleep on a wait queue, wait for IO, take a page
    > fault which has to satisfy disk or call the scheduler directly, they
    > will be rescheduled.

    Thanks for the answer on preemptiveness. In retrospect (now that
    I have the answer) I realize it was probably a dumb question. Where
    is the best source of information on kernel threads? There isn't
    much discussion of them in the source code. I am interested in
    how they are scheduled - it appears they are running at a very high
    priority. It also appears that they are normal processes in the
    view of the scheduler as I can not see any special code to handle
    them in kernel/sched.c. Am I free to alter the priority of a kernel


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