best scheme/lisp for real time code

Is Chicken a good idea? I am worried about the way it does GC. Exhausting the stack seems a bit... Java. I'm looking at Gambit too but I don't know much about it yet.

Whatever I end up using needs to work on ARM. It doesn't have to target C as long as it has FFI and short GC pauses (I am aiming for less than 5ms.)

>>10

The write barrierers--are they used to keep the references from older stack frames valid when moving data? Or have I misunderstood?

Write barrier used when code assigns reference to object O at frame N to a memory cell at frame M, where M < N. On return from frame M, memory manager manger propagates O from M to M-1, unless M=N or reference got overwritten by other object.