kern/55247: Recent tsc changes make clock race (1 hour per day)

[christos%astron.com@localhost]

>Number:         55247
>Category:       kern
>Synopsis:       Recent tsc changes make clock race (1 hour per day)
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri May 08 19:15:00 +0000 2020
>Originator:     Christos Zoulas
>Release:        NetBSD 9.99.60
>Organization:
	Racing Clocks Inc.
>Environment:
System: NetBSD quasar.astron.com 9.99.60 NetBSD 9.99.60 (QUASAR) #165: Tue May 5 20:44:19 EDT 2020 christos%quasar.astron.com@localhost:/usr/src/sys/arch/amd64/compile/QUASAR amd64
Architecture: x86_64
Machine: amd64
>Description:

	Ntp refuses to sync since the clock is racing too fast.

>How-To-Repeat:
        Manufacturer: Dell Inc.
        Product Name: Precision 5820 Tower
	kern.timecounter.choice = TSC(q=3000, f=3850000000 Hz) clockinterrupt(q=0, f=4000 Hz) hpet0(q=2000, f=24000000 Hz) ACPI-Fast(q=1000, f=3579545 Hz) lapic(q=-100, f=25000000 Hz) i8254(q=100, f=1193182 Hz) dummy(q=-1000000, f=1000000 Hz)

>Fix:
	sysctl -w kern.timecounter.hardware=hpet0