Profiler: What is "ParticleSystem.WaitForUpdateThreads"?

Hello,

My profiler while running on an iPhone seems to most of the time be using 25% of each frame on a bunch of calls in “ParticleSystem.WaitForUpdateThreads”->“ParticleSystem.UpdateJob”. It will dip every couple seconds, but go right back up afterward.

No particles are active near the player or on the screen, however.

Is there a way to tell what this means? It doesn’t seem to happen in the editor.

I wrote this a while back, but I’m looking into it again as I’m still having trouble with this. Any ideas?