On Sat, May 27, 2023 at 04:34:27PM +0000, bruma wrote: > > On Sat, May 27, 2023 at 10:29:37AM +0200, Claudio Jeker wrote: > >> On Sat, May 27, 2023 at 09:16:23AM +0100, Stuart Henderson wrote: > >> > On 2023/05/27 06:36, br...@mailbox.org wrote: > >> > > > >> > > > >> > > On Sat, 27 May 2023, Mike Larkin wrote: > >> > > > >> > > > probably IPI traffic then. not sure what else to say. If a few % > >> > > > host overhead > >> > > > is too much fot you with a 16 vCPU VM, I'd suggest reducing that. > >> > > > > >> > > > What is your workload for a 16 vcpu openbsd VM anyway? > >> > > > >> > > I would like to use the OpenBSD VM as my main workstation. I also need > >> > > to > >> > > use Linux for some graphic intensive stuff, so the ideal OpenBSD on > >> > > host > >> > > with vmm for Linux is not an option unfortunately. I guess I could > >> > > accept > >> > > that CPU usage price, but of course not having to pay it would be > >> > > better. > >> > > >> > OpenBSD doesn't do brilliantly with that many CPUs yet. Things are > >> > getting better but I think you're likely to find many workloads are a > >> > bit less laggy with half that. > >> > >> Also a few % CPU on the host can be caused by the interrupts caused by the > >> clocks on every CPU. It may be that we do not select a cheap clock source > >> like TSC and the result is much more overhead on the host. > >> > >> -- > >> :wq Claudio > >> > > > > yes I did not think of that; thanks Claudio! > > > > OP: what is your sysctl kern.timecounter ? > > > > kern.timecounter.tick=1 > kern.timecounter.timestepwarnings=0 > kern.timecounter.hardware=pvclock0 > kern.timecounter.choice=i8254(0) pvclock0(1500) acpihpet0(1000) > acpitimer0(1000) > >
You might try changing this and seeing if the load changes.
