Buildbot Performance

[Christopher Nielsen]

On a semi-related note, relative to port build times in-general…

While building Mame locally numerous times last year, I noticed that link times are excruciating slow: For a standard non-debug build, link times were on the order of 10+ minutes. And for a debug build, it ballooned up to 50+ minutes.

The solution was to use flag ‘-no_deduplicate’, which brought the link times down to 30 seconds or less.

Apparently this is a known problem, based on research. And later versions of Xcode enable that flag by default.

I don’t know if that’s something we might want to start using more broadly, particularly for ports with large code bases?

> On 2021-05-12-W, at 08:41, Christopher Nielsen <mascguy at rochester.rr.com> wrote:
> 
> To clarify my question about overcommitment: Are the total number of virtual CPUs for the buildbot VMs running on a given Xserve, greater than the number of physical CPU cores available?
> 
>> On 2021-05-12-W, at 08:32, Christopher Nielsen <mascguy at rochester.rr.com> wrote:
>> 
>> Looking at the build times for various ports, it varies significantly.
>> 
>> I was curious, are we overcommitting virtual CPUs vs. the number of available physical cores on our Xserves? And is disk swapping coming into play, within the VMs themselves?