cache_lock versus getty?

[walt]

Apologies if this is a frivolous question.  I assume I'm not the
only one seeing the cache_lock: blocked/unblocked on "getty"
messages at boot time?

My puzzle is:  I see the blocked/unblocked messages exactly five
times.  Seems like it should be six (or maybe even seven times)
assuming there would be no cache_lock the first time getty is
looked up, but probably would be for all the remaining times?

Related bone-head unix question:  I don't understand why there
are gettys running on ttyv1-v7 but not on v0, even though there
is a login prompt on v0 and no one logged in on v0.
(The first line of /etc/ttys calls for a getty on ttyv0.)

Thanks for any clues!