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    SubjectRe: Concurrent access to /dev/urandom
    >Even timer interrupts are incredibly unpredictable.  Instructions can
    >take
    >variable times to complete, and all instructions plus some indeterminate
    >cache operations and queue flushing must occur before the CPU can
    >even begin to service an interrupt.

    Well, don't timer interrupts happen every 1/1000 s (unless, of course, cli() is
    in effect)?

    >Also of note, there are small
    >critical
    >sections with interrupts disabled scattered all over the kernel and
    >scheduler,
    >in addition to varying memory latencies, etc. (NOTE: I am not an arch
    >expert

    In case you mean the RDTSC, it is of course better than the I8042, for
    random-aphy.



    Jan Engelhardt
    --
    Gesellschaft für Wissenschaftliche Datenverarbeitung
    Am Fassberg, 37077 Göttingen, www.gwdg.de
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