Re: Concurrent access to /dev/urandom

Jan Engelhardt
2004-11-30T08:24:56Z

>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
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