[Info-vax] clock problems with OpenVMS x86 on VirtualBox

[Simon Clubley]

On 2023-05-12, Arne Vajhøj <arne at vajhoej.dk> wrote:
> On 5/12/2023 1:30 PM, Simon Clubley wrote:
>> On 2023-05-12, Dave Froble <davef at tsoft-inc.com> wrote:
>>> On 5/12/2023 8:14 AM, Simon Clubley wrote:
>>>> That's going to make for some "interesting" real-time program behaviour... :-)
>>>
>>> Do you think any serious real time programmer will run a real time task inside a
>>> VM?  I'm not a real time programmer, and I'd still not do that.
>> 
>> As well as traditional real-time stuff (which I agree with you about BTW),
>
> I would not want to do it on a type 2 hypervisor - there must be
> cases where what is happening on the host OS impact the performance
> of the guest OS.
>
> But with a type 1 hypervisor and no over allocation of resources -
> would it be worse than running on bare metal?
>

A type 1 hypervisor is still a software layer between the hardware and
the RTOS. It would have to _guarantee_ that it would _never_ get in the
way of the timing guarantees that a program running under a RTOS needs.

Simon.

-- 
Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP
Walking destinations on a map are further away than they appear.