3 ms·
> and sends it 1500b at a time sendmmsg (or the upcoming io_uring) let you send multiple UDP packets with a single syscall.
by the8472 8y ago
> and sends it 1500b at a time
sendmmsg (or the upcoming io_uring) let you send multiple UDP packets with a single syscall.
- codys 8y agoWhile this is useful, I don't think it would completely resolve the noted "tons of send syscalls" issue. QUIC performs it's own flow control and I don't think it can just send all the packers composing a file at once (all the time, at least)
- the8472 8y agoIf your server handles many connections simultanously you can still bundle a lot of packets in a single sendmmsg syscall, it can dispatch to a different destination address for each packet.
- drewg123 8y agoBut I think each of these UDP packets will still travel separately from the syscall layer to the NIC (eg, no TSO). So you're still a factor of 40 or so behind TCP + TSO