There is limited chaining capability in io_uring that can be an actual gamechanger if your chain of ops can be fully in-kernel.

An intern of mine wrote a whole tcp-checkpoint-(pause-ingress-and-egress-and-the-socket-save-all-state-unpause-everything)-and-send-full-state-on-other-socket (which was a dozen or so ops - netlink writes, ioctls, set/getsockopt, read/write calls...) in a chain - all in one command-queue-write IIRC.

Performance was as good as an ad-hoc kernel module, without any ebpf. We just had one kernel patch to handle some unhandled syscall (getsockopt ? Setsockopt ? Ioctl?) (that we sadly didn't upstream... 2 years ago) and we were done. Really a great system for batching syscalls.

It made me wish for a form of DAG for error-handling or for parallel operations in chains...