Performance issue: ProgressTracking.Update seems to be O(bodies * vessels)

[JonnyOThan]

In my "twitch plays KSP" stream I have a game save with galaxies unbound + lots of other planet packs (320 bodies in total) and LOTS of kerbals. It was running slow so I decided to attach a profiler and was astonished to see this:

A brand new save in the same universe has ProgressTracking.Update at about 5ms, which is still astonishingly high but is likely related to the number of bodies.

I haven't looked into what this function is doing, but it would be awesome to optimize this.

[JonnyOThan]

Er it's worse than I thought....the top-level seems to iterate over every vessel, and then over every ProgressNode.

...every CelestialBody seems to have 19 sub-nodes.

[JonnyOThan]

I didn't do a very thorough search, but it looks like none of the progress nodes' OnIterateVessel calls needs to do anything with a ship that isn't the active one, and none of the CelestialBody progress nodes need to do anything in OnIterateVessel either. So that's two places to easily skip work.

It could definitely cause issues if any mods add stuff in there though.

[gotmachine]

TBH, I would categorize that as "won't fix". KSP just doesn't scale well at all in some modded scenarios.

320 bodies is just silly. If a mod (or a player) want to do that, then it should be responsible for implementing such a case properly.

I can take a look, but it seem entirely normal for progress tracking to check all vessels, not only the active one. Not saying there isn't room for optimization while keeping stock functionality intact, but I think that having such a large amount of bodies will inevitably cause perf issues in many places, so I don't really see the point, and it's kinda out of the scope of KSPCF to deal with that.

[JonnyOThan]

Galaxies Unbound with all the optional planets is 100-200 bodies I think. And I'm pretty sure the stock code isn't excluding asteroids, flags, and debris.

[JonnyOThan]

I recognize my install is an extreme one, but this change increases my fps by ~50% (33% reduction in frame time) and I'm pretty sure it preserves all stock behavior (but please verify if you're concerned)