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    SubjectRe: Documentation / code sample wanted.
    Hi Dick, All,

    >This has become a FAQ, probably because people
    >don't know what a kernel is. They think it's
    >just some 'C' code in which you can do anything
    >the 'C' compiler lets you do.
    In this case, I was being stupid with the gethostbyname exmaple. But I
    do know what a kernel is !

    To fill in the blanks, I am writing a network based filesystem, and I
    now realise that the place to do the gethostbyname() is in a mount helper.

    >Important! The kernel is not a 'task' it doesn't
    >have a context. Everything it has been designed
    >to do, is to perform systematic tasks upon behalf
    >of the caller, calling from user-mode context.
    >When it is executing, it is executing upon behalf
    >of a user-mode task. It is doing what the user-mode
    >task doesn't know how, or isn't trusted, to do.
    What I would like to achive is a self-contained module which implements
    a filesystem. The user-space apps then interact with the fs as normal.

    I am trying to avoid havng "helper daemons" for various reasons, too
    long to go into here

    >The only thing that can call the kernel and
    >successfully accomplish what it intended to do, is
    >a user-mode task. Therefore, if you want to call
    >the kernel, you do it from a user-mode program.
    >It's just that simple.
    And if your a filesystem ? Is it really recommended to do;

    userspace->kernel->userspace->kernel->userspace ? That seems like a lot
    of context switching to me.

    >You do this, by creating a user-mode daemon that
    >sleeps in select() or poll() until the kernel code
    >wakes it,

    As I said, for my own reasons I would like not to have a deamon like this.

    Thanks for the help.


    Chaos, Panic, Pandemonium... my work here is done.

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