kern/58709: setting CPU frequency to something invalid makes sysctl node disappear

[nia%pkgsrc.org@localhost]

>Number:         58709
>Category:       kern
>Synopsis:       setting CPU frequency to something invalid makes sysctl node disappear
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Sep 29 07:40:00 +0000 2024
>Originator:     nia
>Release:        NetBSD 10.0_STABLE
>Organization:
The NetBSD Foundation, Inc
>Environment:
NetBSD amnesia 10.0_STABLE NetBSD 10.0_STABLE (GENERIC) #0: Thu Sep 12 20:23:07 UTC 2024  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/amd64/compile/GENERIC amd6
>Description:
visible in dmesg:
acpicpu0: autoconfiguration error: failed to get frequency (err 5)
>How-To-Repeat:
Make a typo like

# sysctl -w machdep.cpu.frequency.target=177

instead of 

# sysctl -w machdep.cpu.frequency.target=1700
>Fix:
reboot