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    SubjectRe: periods and deadlines in SCHED_DEADLINE
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    On Fri, 2010-07-09 at 16:24 +0200, Peter Zijlstra wrote:
    > On Fri, 2010-07-09 at 15:38 +0200, Raistlin wrote:
    > > Basically, from the scheduling point of view, what it could happen is
    > > that I'm still _NOT_ going to allow a task with runtime Q_i, deadline
    > > D_i and period P_i to use more bandwidth than Q_i/P_i, I'm still using D
    > > for scheduling but the passing of the simple in-kernel admission test
    > > Sum_i(Q_i/P_i)<1 won't guarantee that the task will always finish its
    > > jobs before D.
    >
    > But the tardiness would still be bounded, right? So its a valid Soft-RT
    > model?
    I think that if Sum_i(Q_i/P_i)<1 but Sum_i(Q_i/min{P_i,D_i})>=1 then you
    can have sporadic deadline misses, but it should still be possible to
    compute an upper bound for the tardiness.
    But this is just a feeling, I have no proof... :)


    Luca



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