Tracy is a frame profiler: https://github.com/wolfpld/tracy
This uses Tracy's C API to instrument the code (already added in several
places). It turns out there is something very weird with the fence
behavior between the staging buffers and render commands as the
inter-frame delay occurs in a very strangle place (in the draw code's
packet acquisition rather than the fence waiter that's there for that
purpose). I suspect some tangled dependencies.
