If you care about latency, not performance, I think it's fine? You can do a Cheney semispace collector in which it's safe to allocate in interrupt handlers if y

If you care about latency, not performance, I think it's fine? You can do a Cheney semispace collector in which it's safe to allocate in interrupt handlers if you have control over the ABI (and you've got a few registers to spare) or if your instruction set provides an "increment this memory location" instruction.