i wrote a quic performance tool to research maximal quic server performance namely syscalls vs io-uring and quic library vs library (in an apples to apples scenario). i'm having some issues with the stability of the io-uring networking layer... and at least thought my rings were just overflowing, but they aren't. during most runs, all of a sudden submitted sendmsg ops start failing and returning -ETIME... even though there are absolutely no timeouts associated with those operations. and it's always that -ETIME error delivered once things start to fail. the only performance test implemented so far is a 1GB transfer over udp over ipv6 loopback. my working guess at the moment is that the operation pressure rate is exposing some kind of bug somewhere in io-ring? i just posted the project on github. the README is basic but i think provides enough instructions to run the binaries and see for yourself. let me know what data i can extract so we can quickly rule this definitely my bug or definitely an io-uring bug. it's really the bizzare -ETIME that makes me think it might not be mine. the code is super brief, check perf.networking.cpp https://github.com/victorstewart/quicperf
