I'm running into an issue with WebGL in Google Chrome (61.0) with really long frames that occur around once every 60-90 seconds on my machine. Devtools logs these frames as GPU activity, but what is actually causing these frames to be long is opaque to me. The app is using REGL and updating attribute buffers every frame with subdata. I'm looking for insight into what could be causing these long frames, and how to move forward debugging them, as Chrome's devtools provide no details about GPU frames.
This issue does not occur with Safari 11.0
After further investigation it seems related to use of the ANGLE_instanced_arrays extension. This issue does not occur when disabling instancing and drawing each instance with a separate draw call.
