Re: What to do about "WARNING: negative runtime; monotonic clock has gone backwards"

[Brad Spencer <brad%anduin.eldar.org@localhost>]

Taylor R Campbell <riastradh%NetBSD.org@localhost> writes:

>> Date: Fri, 28 Jul 2023 07:42:04 -0400
>> From: Brad Spencer <brad%anduin.eldar.org@localhost>
>> 
>> dtrace: invalid probe specifier sdt:xen:hardclock:jump { @ = quantize(arg1 - arg0) } tick-10s { printa(@) }: probe description :::tick-10s does not match any probes
>
> modload dtrace_profile

Another data point or three...  as mentioned in the previous email, the
above probe panics the -current PV kernel after a few seconds.  It
appears to work if you leave off the '-10s' part, however.  Further, it
appears to work as presented with the GENERIC kernel in PVH mode.  I
suspect that running in PVH mode changes a lot of things around, so the
comparison is likely not valid.  In fact, I run a PVH NetBSD 10_BETA
system with 2 VCPUs and it never has the negative runtime problem (as
far as I know).  The work load is quite a bit different, but it may be
that the problem is limited to just DOMU PV guests.



-- 
Brad Spencer - brad%anduin.eldar.org@localhost - KC8VKS - http://anduin.eldar.org