Many of you know that the random number generator /dev/random
is subject to delays when it has "not accumulated enough entropy",
which is to say randomness.  These delays are said to be longer
on Linux /dev/random that on some other Unices.  They occur
particularly after a system is booted, which I hear is a regular
occurrence on some smoke-test systems.

But I bet many of you will be surprised by the magnitude of the
delays that can occur.

Recently one perl tester's Linux system tested my module IPC::MMA
version 0.58, which used /dev/random to drive testing, to produce
report 5888084.  It took 22320 wallclock seconds to complete the
tests: 6.2 hours.

A few days later the same system tested version 0.58001, which
differs from 0.58 mainly in using /dev/urandom which is not subject
to "entropy delays".  Report 5889682 shows that it took 5 wallclock
seconds.

Anyway, I found it interesting,
Craig MacKenna

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