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

["Jason Thorpe via gnats" <gnats-admin%NetBSD.org@localhost>]

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

From: Jason Thorpe <thorpej%me.com@localhost>
To: Taylor R Campbell <riastradh%NetBSD.org@localhost>
Cc: "gnats-bugs%netbsd.org@localhost" <gnats-bugs%NetBSD.org@localhost>,
 "netbsd-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 06:42:14 -0700

 > On Aug 17, 2026, at 6:19=E2=80=AFAM, Taylor R Campbell =
 <riastradh%NetBSD.org@localhost> wrote:
 >=20
 > 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.)
 
 The cache can=E2=80=99t live on /var because /var might not be available =
 when the cache is required (this would especially be the case for =
 read-only roots).  The only path that=E2=80=99s currently guaranteed to =
 be available when /etc/rc starts processing the rc.d scripts is /etc.  =
 It=E2=80=99s pretty straightforward to suppress any error messages that =
 might occur when writing out the cache (which happens as the last step =
 of the boot process).  And, yes, I can refactor the code that builds and =
 writes out the cache into rc.subr so that there can be a =E2=80=9Cnostart=E2=
 =80=9D rc.d script to rebuild it for those who wish to do that before =
 the next reboot.
 
 -- thorpej