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    SubjectRe: [PATCH] O12.2int for interactivity
    Quoting Timothy Miller <miller@techsource.com>:
    >
    > The interactivity detection algorithm will always be inherently
    > imperfect. Given that it is not psychic, it cannot tell in advance
    > whether or not a given process is supposed to be interactive, so it must
    > GUESS based on its behavior.
    >
    > Furthermore, for any given scheduler algorithm, it is ALWAYS possible to
    > write a program which causes it to misbehave.
    >
    > This "thud" program is Goedel's theorem for the interactivity scheduler
    > (well, that's not exactly right, but you get the idea). It breaks the
    > system. If you redesign the scheduler to make "thud" work, then someone
    > will write "thud2" (which is what you have just done!) which breaks the
    > scheduler. Ad infinitum. It will never end. And in this case,
    > optimizing for "thud" is likely also to make some other much more common
    > situations WORSE.
    >
    >
    > So, while it MAY be of value to write a few "thud" programs, don't let
    > it go too far. The scheduler should optimize for REAL loads -- things
    > that people actually DO. You will always be able to break it by
    > reverse-engineering it and writing a program which violates its
    > expectations. Don't worry about it. You will always be able to break
    > it if you try hard enough.

    Thank you for your commentary which I agree with. With respect to these
    potential issues I have always worked on a fix for where I thought real world
    applications might cause these rather than try and fix it for just that program.
    It was actually the opposite reason that my patch prevented thud from working;
    it is idle tasks that become suddenly cpu hogs that in the real world are
    potential starvers, and I made a useful fix for that issue. Thud just happened
    to simulate those conditions and I only tested for it after I heard of thud. So
    just a (hopefully reassuring) reminder; I'm not making an xmms interactivity
    estimator, nor an X estimator, nor a "fix this exploit" one and so on.

    Con
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