Re: [issue1029] Dragonfly under KVM

[Cédric Berger <cedric@xxxxxxxxx>]

Sepherosa Ziehau wrote:
> On Sat, Jun 7, 2008 at 7:56 PM, Gary Allan <dragonfly@gallan.co.uk> wrote:
> > As Freddie says I'm running the QEmu KVM software on Ubuntu x64. DragonFly
> > is running 32bit with 3.5Gb RAM and 4 CPUs (AMD-Phenom).
> > I can also trigger SMP DragonFly to lock up during a buildworld on VMWare
> > Server 1.0.5 (Dual Core, 2Gb RAM) and VirtualBox. I haven't tried the bare
> > metal but could do so if anyone thinks it would be useful. I'm running HEAD
> > as of yesterday but 1.12.2 also locks up.
> >
> > The kernel is GENERIC with "options SMP" and "options APIC_IO" enabled and
>
> I have a box using Phenom 9550 and 2GB ram.  Dfly HEAD runs directly
> on the box (no virtual tech involved).  Kernel is configured with SMP
> and APIC_IO.  I build world and kernel with -j 8 or -j 16 w/o any
> issues.

I've had issues like this with OpenBSD on VMWare a couple year ago.
Actually, VMs emulate "bare metal" systems very well, but they introduce
very unusual timings. So if you've a race that is "to short to be a
serious problem", than that race might well become a real problem on
VMs. To sum up, testing OSes on virtualized environment is a good way
to find hidden/rare bugs :)

Cedric