You're never going to fit Ardour's engine into 1M instructions, nor is it going to work without unbounded loops. So that's not going to happen.
More interesting would be using BPF for the driver and being able to directly invoke JACK (or some other user-space endpoint) in a way that essentially bypasses the scheduler.
Put differently: rather than rely on the normal scheduler pathway to waking up JACK (or some other user-space endpoint), have BPF do it as soon as the device driver is ready.
But I don't think BPF has any way to do this at present - it seems to rely on accumulation of data in kernel space and a user space poll-driven process to pick it up and push it at the user.
sure there could, but that's utterly unrelated in practical terms to what i think we're discussing, which is ways in which eBPF could impact full-scale audio software rather than limited inline DSP.
More interesting would be using BPF for the driver and being able to directly invoke JACK (or some other user-space endpoint) in a way that essentially bypasses the scheduler.
Put differently: rather than rely on the normal scheduler pathway to waking up JACK (or some other user-space endpoint), have BPF do it as soon as the device driver is ready.
But I don't think BPF has any way to do this at present - it seems to rely on accumulation of data in kernel space and a user space poll-driven process to pick it up and push it at the user.