From the kernel docs: https://www.kernel.org/doc/Documentation/networking/scaling....
""" While RPS steers packets solely based on hash, and thus generally provides good load distribution, it does not take into account application locality. This is accomplished by Receive Flow Steering (RFS). The goal of RFS is to increase datacache hitrate by steering kernel processing of packets to the CPU where the application thread consuming the packet is running. RFS relies on the same RPS mechanisms to enqueue packets onto the backlog of another CPU and to wake up that CPU. """
I have zero problem doing 25G and 40G ethernet at the Linux kernel in RHEL7 (I run Kubernetes clusters on them in fact). Non-ethernet (Infiniband) 100G+ line rate is also totally doable, but IB is an entirely different beast. I agree with you it isn't going to work in the long term, but it should be fine in the medium term. The long term Linux change is likely to just rewrite more and more of the existing filtering code ontop of the eBPF vm, which is fast as holy hell and is replacing large swaths of existing filtering mechanisms for a reason.