Recent qemu and timers issue

[Jedrzej Kalinowski]

Hi all,

When running FreeBSD 8-CURRENT system inside a qemu machine (from the
latest port by nox at freebsd.org) I have strange timer problems in the
virtual machine.

My logs and console are full of messages like this:
calcru: runtime went backwards from 11248014678717988 usec to 119242 usec
for pid 60 (ps)                                                            
        
calcru: runtime went backwards from 11248014678921829 usec to 2516605 usec
for pid 60 (ps)                                                            
calcru: runtime went backwards from 7014844 usec to 6270851 usec for pid 0
(kernel)

It even happens for some processes to die inside qemu guest.

I tried to use all possible timers using sysctl, where I have:
TSC(800) HPET(900) ACPI-safe(850) i8254(0) dummy(-1000000)
None of these helped.


What's more I cannot corelate this with kern.hz value set for the system. I
tried to set it to the same value as host machine, bigger and smaller one.
It's not a kqemu issue, happens also with -no-kqemu switch.

I've already posted this issue on freebsd-current some time ago, but
unfortunately noone showed interest in it..
(http://docs.freebsd.org/cgi/mid.cgi?3cd67c0d967b2464a4b40bd85582bf88)

I would greatly appreciate any help or a hint - where should I look for
help on this issue. 


Cheers,
Jędrzej Kalinowski