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    SubjectRe: [PATCH] Use uname not sysctl to get the kernel revision
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    Ar Mer, 2006-07-12 am 16:26 -0600, ysgrifennodd Eric W. Biederman:
    > If the lock is not short lived then the release is like to be a long
    > ways off. If the lock is not highly contended then you are not likely
    > to hit the window when someone else as the contended lock.
    >
    > How frequent are highly contended short lived locks in user space?

    I'm not sure it matters.

    If you want to do the job right then do this

    - Stick an indicator of how much else wants to run on this CPU in the
    vsyscall page or similar location

    In your locks you can now do

    while(try_and_grab_lock() == FAILED) {
    if (kernelpage->waiting > 0)
    sys_somelockwaitthing()
    }

    Furthermore the kernel can be intelligent about the waiting indicator
    for power or other global scheduling reasons

    [Disclaimer: There is a patent issue around this technique but its not
    one that will impact GPL code as permissions are given for GPL use.]

    Alan

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