Hi Brenden, I don't quite understand the semantics of the XDP userspace interface.
We allow XDP programs to be (unconditionally) exchanged by another program, this avoids taking the link down+up and avoids reallocating RX ring resources (which is great). We have two XDP samples programs in samples/bpf/ xdp1 and xdp2. Now I want to first load xdp1 and then to avoid the linkdown I load xdp2, and then afterwards remove/stop program xdp1. This does NOT work, because (in samples/bpf/xdp1_user.c) when xdp1 exits it unconditionally removes the running XDP program (loaded by xdp2) via set_link_xdp_fd(ifindex, -1). The xdp2 user program is still running, and is unaware of its xdp/bpf program have been unloaded. I find this userspace interface confusing. What this your intention? Perhaps you can explain what the intended semantics or specification is? -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat Author of http://www.iptv-analyzer.org LinkedIn: http://www.linkedin.com/in/brouer
