kern/56968: I have kernel threads sitting in carp_wqinput (x NCPU) even through I'm not using CARP

[thorpej%me.com@localhost]

>Number:         56968
>Category:       kern
>Synopsis:       I have kernel threads sitting in carp_wqinput (x NCPU) even through I'm not using CARP
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Aug 17 04:20:00 +0000 2022
>Originator:     Jason Thorpe
>Release:        NetBSD 9.99.99
>Organization:
RISCy Business
>Environment:
This machine: https://dmesgd.nycbug.org/index.cgi?do=view&id=6646
>Description:
I'm not using CARP, but I have a bunch of kernel threads waiting to handle CARP input -- one per CPU core.  This is an annoying waste of system resources.
>How-To-Repeat:
Boot the system.
>Fix:
threadpool-based workqueue?  (That might not be the best solution for all cases of workqueue, tho.). At the very least, defer creation of the wqinput stuff for CARP until someone actually shows intent to use it.