Subject: Re: Not quite sure where to send this
To: Martin Husemann <>
From: Greywolf <>
List: tech-userlevel
Date: 08/16/2002 11:27:07
Martin, danke!

I'm going over the problem, and it seems there are several other
scripts in /etc/rc which could trigger this behaviour.  I'm not so
sure that doing this going forward is such a hot idea.  It's prone
to frailty (downinterfaces is a perfect example of this).

I have a question:

rc_fast_and_loose's purpose is to avoid spawning a subshell for each
script.  Is this measure done in order to avoid the overhead associated
with the fork(), or is it to avoid the constant re-reading of rc.conf?

If it's not done already (I'm going to go look), why not just surround
the ". /etc/rc.conf" with

+ set -a
  . /etc/rc.conf
+ set +a

in order to make the variables from rc.conf visible to the subshells?
This will eliminate much of the overhead which was dreaded.  It won't
help with the overhead of fork()/exec(), but considering what gets run
inside the scripts anyway, I think one fork()/exec() extra per script
isn't going to kill us, even on a slow machine.

The idea, as I understand it, was that rc.conf should only ever need
to be read once.

On Fri, 16 Aug 2002, Martin Husemann wrote:

# Date: Fri, 16 Aug 2002 20:05:59 +0200
# From: Martin Husemann <>
# To: Greywolf <>
# Cc:
# Subject: Re: Not quite sure where to send this
# > FIX #1:
# > 	Somehow fix /etc/rc.d/downinterfaces to handle this more
# > 	gracefully.
# Done.

NetBSD: Get Over It.