Some fun performance notes from Keith today

I don’t think he’ll mind if I share these tidbits from his victories.  All of the below is written by him:

Commit Notes

– moved main sim execution to separate thread- moved most of the “ui reading the current gamestate” stuff to that thread too

– moved the generation of sync data to that thread as well

– moved the update-visual-object stuff outside of process-sim-step; still on the main thread of course but now it’s easier for you to profile it without sim stuff cluttering up the results

– various performance improvements, some of which are fairly significant

Comments

So right now there’s some volatility in the visualization code but it’s not causing problems right now since I think it’s mostly dealing in primitive types. Will need to be dealt with later but doesn’t appear pressing.

Performance-wise the sim’s burden on the main thread is almost gone during most frames. There’s still some spikes when a lot of entities die at once, as that’s a lot of list removal work. I can actually optimize that a bit more, but for now with the sim-on-the-main-thread almost always under 2ms (and often way under that) I figured this was ok for now 🙂

Addendum

Oh, I should also mention that the main thread per-frame heap alloc is also almost gone, and most of that was eliminated rather than just shifted elsewhere.

One Hour Later

I’m currently working on the other-thread heap alloc, via the deep-profiler and setting SimPlanningLoop.IsOnMainThreadForProfilingPurposes to true. It just makes everything execute sequentially, rather than farming it out.

Another Hour Later

Just nuked the heap alloc of the short term planning threads (which do most of the work) from about 800k to about 40k; I can cut about 25k more, too, just needed to go now. The remaining looks like legitimate allocation on the partition list (used for find-everything-within-range checks), and that should in theory stop once the list is big enough that all future checks use less space.

The execution thread is still doing 300k+ per go, and I’ll take a look at that later. Not sure what the long term (AI) thread is doing heap-wise, haven’t seen it in the results yet.

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