kern/54270: Clock standing still (arm64 current on rpi3)

[spam%engbloms.fi@localhost]

>Number:         54270
>Category:       kern
>Synopsis:       Clock standing still (arm64 current on rpi3)
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Jun 04 10:35:00 +0000 2019
>Originator:     Lars Engblom
>Release:        NetBSD-evbarm-aarch64-201906021110Z-generic.img
>Organization:
>Environment:
NetBSD arm64 8.99.42 NetBSD 8.99.42 (GENERIC64) #0: Fri May 31 16:38:27 UTC 2019  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/evbarm/compile/GENERIC64 evbarm

>Description:
Sometimes, especially under load, the clock stands still. When repetitively checking the time with "date", the time has not changed at all between each try. All tools requiring clock for repeating things (for example top) does not work.

While the clock is hanging no error message is appearing in dmesg. After a very wait (maybe 20-30minutes) the hang suddenly stopped and this appeared in dmesg: [  2812.933308] WARNING: negative runtime; monotonic clock has gone backwards
>How-To-Repeat:
I triggered this problem twice while trying to compile vim with lua, ruby and python support from pkgsrc.
>Fix: