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    SubjectRe: [PATCH] [request for inclusion] Realtime LSM
    On Tue, Jan 11, 2005 at 08:05:08AM -0500, Paul Davis wrote:
    > >> Running `nice --20' is still significantly worse than SCHED_FIFO, but
    > >> not the unmitigated disaster shown in the middle column. But, this
    > >> improved performance is still not adequate for audio work. The worst
    > >> delay was absurdly long (~1/2 sec).
    > >
    > >Let's work on that. It'd be _far_ better to have unprivileged near-RT
    > >capability everywhere without potential scheduling DoS.
    >
    > I am not sure what you mean here. I think we've established that
    > SCHED_OTHER cannot be made adequate for realtime audio work. Its
    > intended purpose (timesharing the machine in ways that should
    > generally benefit tasks that don't do a lot and/or are dominated by
    > user interaction, thus rendering the machine apparently responsive) is
    > really at odds with what we need.

    We have not established that at all. In principle, because SCHED_OTHER
    tasks running at full priority lie on the boundary between SCHED_OTHER
    and SCHED_FIFO, they can be made to run arbitrarily close to the
    performance of tasks in SCHED_FIFO. With the upside that they won't be
    able to deadlock the machine.

    And I mean arbitrarily close in the strict delta-epsilon sense.
    It's not perfect, but neither is SCHED_FIFO, in principle or in
    practice.

    --
    Mathematics is the supreme nostalgia of our time.
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