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    SubjectRe: Renice X for cpu schedulers
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    On Thu, Apr 19, 2007 at 05:20:53PM -0700, Michael K. Edwards wrote:
    > Embedded systems are already in 2007, and the mainline Linux scheduler
    > frankly sucks on them, because it thinks it's back in the 1960's with
    > a fixed supply and captive demand, pissing away "CPU bandwidth" as
    > waste heat. Not to say it's an easy problem; even academics with a
    > dozen publications in this area don't seem to be able to model energy
    > usage to the nearest big O, let alone design a stable economic
    > dispatch engine. But it helps to acknowledge what the problem is:
    > even in a 1960's raised-floor screaming-air-conditioners
    > screw-the-power-bill machine room, you can't actually run a
    > half-decent CPU flat out any more without burning it to a crisp.
    > stupid. What's your excuse? ;-)

    It's now possible to QoS significant parts of the kernel since we now
    have a deadline mechanism in place. In the original 2.4 kernel, TimeSys's
    irq-thread allowed for the processing of skbuffs in a thread under a CPU
    reservation run category which was use to provide QoS I believe. This
    basic mechanish can now be generalized to many place in the kernel and
    put it under scheduler control.

    It's just a matter of who and when somebody is going take on this task.

    bill

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