Re: bhyve vCPU limit

Hi

On Wed, Dec 1, 2021 at 7:52 PM Miroslav Lachman <000.fbsd@quip.cz> wrote:
>I was playing with VMs in VirtualBox and Bhyve and compared
> performance with increasing vCPU count. The more cores VM get the slower

How many physical cores you have on the host? This is a characteristic
behavior when overcoming.
But without overcommit I observe productivity growth:

1)
Single vCore  benchmark via cpuminer: https://pastebin.com/mg46RvDT
TOP from host: https://pastebin.com/LvbBiyFz


2)
Sixteen vCore benchmark via cpuminer: https://pastebin.com/7FQjaVM8
TOP from host: https://pastebin.com/dLpreq9D

I observe almost linear growth.

In addition, the loss of performance can be associated with NUMA
(required cpuset/cpuset_setaffinity
and control of memory capacity)

As far as I remember, it is not enough to simply change one parameter
in .h file: https://bhyvecon.org/bhyveconOttawa2019-Rodney.pdf