Re: Improving the performance of system boot by eliding unused rc.d scripts and caching the result

[David Holland <dholland-tech%netbsd.org@localhost>]

On Thu, Aug 20, 2026 at 12:35:42PM -0400, Greg Troxel wrote:
 > >  > How would you store and configuration manage the ordering requirements
 > >  > among barrier scripts?
 > >
 > > Just off the top of my head, you could:
 > >
 > >  - hardwire the barrier sequence (admittedly not a great plan)
 > >  - put it on the rcorder command line
 > >  - put it all in a single non-executable file
 > 
 > I can see those working -- but I don't see how that's an improvement,
 > weighing the benefit of dropping these tiny files and invoking them vs
 > the cost of adding additional mechanisms, absent benchmarks that show
 > the current situation hurts.

Running a shell on the empty file is not free, even if it's not
expensive. (AIUI, without the fast-and-loose setting, each one of
these is run in at least a subshell if not a fresh exec.)

Conversely, rcorder(8) is compiled code and a bit of extra logic there
is by comparison free... plus there you're saving opening and reading
a few files so you're still ahead.

 > After all, anyone truly concerned about performance would port systemd
 > to NetBSD and vibe-code optimizations.

Right, obviously :-)

-- 
David A. Holland
dholland%netbsd.org@localhost