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    SubjectRe: [RFC 8/12][PATCH] SCHED_DEADLINE: wait next instance syscall added.
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    On Fri, 2009-10-16 at 17:44 +0200, Raistlin wrote:
    > This commit introduces another new SCHED_DEADLINE related syscall. It is
    > called sched_wait_interval() and it has close-to-clock_nanosleep semantic.
    >
    > However, for SCHED_DEADLINE tasks, it should be the call with which each
    > job closes its current instance. In fact, in this case, the task is put to
    > sleep and, when it wakes up, the scheduler is informed that a new job
    > arrived, saving the overhead that usually comes with a task activation
    > to enforce maximum task bandwidth.

    The changelog suggests (and a very brief looks seems to confirm) that
    this code could be much smaller by using hrtimer_nanosleep().

    The implementation as presented seems to only call ->wait_interval()
    when the timer arms, which seems like a bug, we should always call it,
    regardless of whether we're on a period boundary.



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