Re: [9fans] port/devcons.c is not port-able

[Geoff Collyer <geoff@collyer.net>]

It's just not the amount of mechanism at issue, but the odds of a
panic message or other serious complaint being seen, for instance.  If
you've got console prints going only to a pipe, and the process
reading the pipe blocks, for a while prints will go into pipe
buffering (and not be seen) and then finally kernel processes doing
prints will start to block when the pipe buffering fills.

Actually, the panic case is worse: the message would go into pipe
buffering, and no matter what the reading process is doing, the system
will shut down and the reading process is unlikely to run (or run for
long enough to matter), and again the message wouldn't be seen.  So
the user experience of a panic in that case would be either a
mysterious hang of the entire system or a sudden blanking of the
screen and a reboot, possibly both (the hang, a delay and a reboot).

The current devcons is messy but pragmatic.  Plugging your serial
consoles into a console server gives you remote access to the consoles
and logging.