Re: bin/60607: /etc/rc does too much throw-away work and is needlessly slow on constrained systems

["Taylor R Campbell via gnats" <gnats-admin%NetBSD.org@localhost>]

The following reply was made to PR bin/60607; it has been noted by GNATS.

From: Taylor R Campbell <riastradh%NetBSD.org@localhost>
To: Jason Thorpe <thorpej%me.com@localhost>
Cc: gnats-bugs%NetBSD.org@localhost, netbsd-bugs%NetBSD.org@localhost
Subject: Re: bin/60607: /etc/rc does too much throw-away work and is needlessly slow on constrained systems
Date: Mon, 17 Aug 2026 13:19:16 +0000

 > Date: Mon, 17 Aug 2026 05:35:00 +0000 (UTC)
 > From: Jason Thorpe <thorpej%me.com@localhost>
 > 
 > I've devised a simple solution to the problem that's minimally
 > invasive and, on the wrap030 homebrew, cuts the boot time (with
 > ldconfig=NO) from ~13 minutes to ~7 minutes.
 
 Nice!
 
 > 2. Another small change to /etc/rc where the real work of invoking
 > the rc.d scripts is performed.  This second change introduces the
 > notion of the "rcorder.cache".  At boot time, if it is determined
 > that the cache needs to be rebuilt, then all of the rc.d scripts are
 > interrogated in rcorder-order to see if they will do work.  If so,
 > they're added to the list, otherwise they are ignored.  Once the
 > list is built, then the list is invoked to start each service in the
 > normal way.  The list is saved in the "rcorder.cache" and consulted
 > at the next boot.  The cache is invalidated by modifying
 > /etc/rc.conf, /etc/rc.d, or by manually removing /etc/rcorder.cache.
 
 Can you make this part optional, and/or populated up front at
 build-time or repopulated on request?  It would be nice if we could
 boot to multi-user from a read-only /, with all state stored on other
 file systems like /var, and without spurious EROFS warnings spewed to
 the console.  (I know we'll hit issues with, e.g., /etc/motd today,
 but I'd like to avoid adding more issues.)