At least for user space usage, I'm not sure a new kernel thing is needed. Quite a while ago I have implemented a user space (single producer / single consumer)

At least for user space usage, I'm not sure a new kernel thing is needed. Quite a while ago I have implemented a user space (single producer / single consumer) ring buffer, which uses an eventfd to mimic pipe behavior and functionality quite closely (i.e. being able to sleep & poll for ring buffer full/empty situations), but otherwise operates lockless and without syscall overhead.