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> 22.10.2017 01:15, Ian Lepore ?????:
> > On Sat, 2017-10-21 at 17:07 -0400, Michael Voorhis wrote:
> >> Ian Lepore writes:
> >>> Beyond that, I'm not sure what else to try. ?It might be necessary to
> >>> get some bhyve developers involved (I know almost nothing about it).
> >> NTPD behaves more normally on uniprocessor VMs.
> >> A FreeBSD bhyve-guest running on a freebsd host will select a
> >> different timecounter depending on whether it is a multiprocessor or a
> >> uniprocessor.??My uniprocessor bhyve-vm selected TSC-low as the best
> >> timecounter in a uniprocessor.??NTP functions there as expected.
> >> kern.timecounter.choice: TSC-low(1000) ACPI-fast(900) HPET(950) i8254(0)
> >> dummy(-1000000)
> >> kern.timecounter.hardware: TSC-low
> >> The very same VM, when given two total CPUs, selected HPET (if I
> >> recall) and the timekeeping with NTPD was unreliable, with many
> >> step-resets to the clock.
> > Hmm, I just had glance at the code in?sys/amd64/vmm/io/vhpet.c and it
> > looks right. ?I wonder if this is just a simple roundoff error in
> > converting between 10.0MHz and SBT units? ?If so, that could be wished
> > away easily by using a power-of-2 frequency for the virtual HPET. ?I
> > wonder if the attached patch is all that's needed?
> I've tried the patch (at bhyve guest) and nothing has changed. Should
> the patched system be tested at bhyve guest or bhyve host?
I believe the suggested patch would have to be made to the bhyve
host. Also on the host and guest what are the values of
Getting good ntpd behavior in a VM guest of any kind is sometimes a
non trivial thing to do.
Rod Grimes rgri...@freebsd.org
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