Buildbot Performance

[Daniel J. Luke]

On May 17, 2021, at 2:03 AM, Ryan Schmidt <ryandesign at macports.org> wrote:
> On May 16, 2021, at 17:57, Daniel J. Luke wrote:
>> On May 16, 2021, at 10:48 AM, Christopher Nielsen wrote:
>>> I’d bet the hypervisor is spending more time on scheduling and pre-emption, than actual processing time.
>> 
>> This is something we could actually measure, though, right? Then we don't have to just speculate (and if we do determine that a config change needs to happen, we can use the actual measurements to help us optimize the configuration).
> 
> What would be your suggested methodology?

I'm not an ESXi expert but after a quick look through some of their documentation it looks like there's an `esxtop` command that can show some information. More info here: https://kb.vmware.com/s/article/1005362 (some google searches seem to indicate that when the oversubscription is a problem, it's usually because ESXi is waiting for 'enough' cores to be available to start all of the vCPUs - and that this used to be much worse in older ESXi versions, but can still be a problem). This post also has information that looks useful: https://www.heroix.com/blog/vmware-vcpu-over-allocation/

-- 
Daniel J. Luke