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    Subject[Question]How to restrict some kind of task?
    Hi, All.

    I want to restrict some kind of task.

    For example, for some task have one schedule policy SCHED_XYZ, when
    it reach beyond
    40% CPU time, we force it yield CPU.

    I inserted some code in scheduler_tick(), like this:

    > if (check_task_overload(rq)) {
    > if (xyz_task(p) && yield_cpu(p, rq)) {
    > set_tsk_need_resched(p);
    > p->prio = effective_prio(p);
    > p->time_slice = task_timeslice(p);
    > p->first_time_slice = 0;
    > goto out_unlock;
    > }
    > }

    Of course, before these code, we hold our rq->lock first, so we should
    go to 'out_unlock'.
    The function xyz_task(p) just is macro (p->policy == SCHED_XYZ), and
    yield_cpu() also is simple, it just move the task to expired array,

    int yield_cpu(task_t *p, runqueue_t *rq)
    dequeue_task(p, p->array);
    requeue_task(p, rq->expired);
    return 1;

    These code are so simple, but is make system crash, if I create some
    XYZ policy task.

    I tried the more radical idea (remove these tasks from runqueue to
    our one
    list_head that spin_lock protected), but crash again and again.

    if need, I can paste my global patch.

    Thanks in advanced.


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      Last update: 2005-11-15 11:20    [W:0.020 / U:2.888 seconds]
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