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    SubjectRe: Interesting analysis of linux kernel threading by IBM
    : > No, yet again the _app_ design you propose is the bottleneck.
    : I'll respect Your opinion but the mine is different.

    I spent the day yesterday cutting down a tree (a college era skill I
    aquired, long story), so I just went through all the mail on this

    Somebody, apologies for not remembering who, said this is turning into
    a "he said, she said" type of argument and I have to agree.

    At this point, Davide, it has been made clear that there are a number
    of people who have experience and are saying that your approach has
    a strong chance of being, err, less than optimal. You and the other
    fix-the-scheduler people seem pretty insistent that it is the right
    thing to do.

    The other side is saying ``this application design will yield poor
    performance, and in general, we believe that the right number of active
    processes or threads is N | N == #CPUS perhaps plus a small number of
    controller threads.''

    Given that there is enough controversy on both sides, and that you want
    the scheduler to change over the objects of a number of experienced people
    who believe that it's a bad idea, I think it is reasonable to ask that
    you demonstrate that your application does indeed perform better with
    your model. So please code up a pair of benchmarks, one which does
    all the work in one thread (but can have N concurrent threads running)
    and one that does the work in the pipeline. If you can show that the
    model you propose has _BETTER_ performance than the other model, then
    there is indeed a good reason to consider the scheduler changes. If the
    performance is worse, or even the same, then there really is not much
    reason to make any changes. If the performance were the same in both
    cases, you could argue that the threaded model has a nicer programming
    model and we should support it. Let's cross that bridge when we come
    to it, the first step is to get the benchmarks.

    I strongly feel that since you are pushing for this, the benchmarks are
    something you need to do. You are perfectly qualified to do them because
    you understand your application, and I at least, apparently don't. So
    please come forward with the benchmarks and the results and until then,
    let's drop this topic. I think we've pushed it as far as we can in this
    forum. Any objections from anyone?

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