Re: zero runtime when negative

[mlelstv%serpens.de@localhost (Michael van Elst)]

cheusov%tut.by@localhost (Aleksey Cheusov) writes:

>As NetBSD is widely used as a "guest" OS inside vmware/qemu/kvm/xen
>it would be nice to treat this problem as "must be fixed in 6.0".

I think that's just a conflict of interest in the emulator/virtual machine
that makes it emulate hardware not the way we expect it.

The timecounter code requires that overflows of the counter hardware
are seen by hardclock(). That may or may not be correct for the emulated
or virtualized hardware.

I used to get such negative time a lot when emulating an Amiga computer,
but with the current emulator code it never happens. As a downside, the
timecounter isn't very smooth, counting very quickly and then being
suspended, so that only on average it meets real-time.

-- 
-- 
                                Michael van Elst
Internet: mlelstv%serpens.de@localhost
                                "A potential Snark may lurk in every tree."