On 11/28/19 2:17 AM, David Laight wrote:

From: Eric Dumazet

quoted

Sent: 27 November 2019 17:47

...

quoted

A QUIC server handles hundred of thousands of ' UDP flows' all using only one UDP socket
per cpu.

This is really the only way to scale, and does not need kernel changes to efficiently
organize millions of UDP sockets (huge memory footprint even if we get right how
we manage them)

Given that UDP has no state, there is really no point trying to have one UDP
socket per flow, and having to deal with epoll()/poll() overhead.

How can you do that when all the UDP flows have different destination port numbers?
These are message flows not idempotent requests.
I don't really want to collect the packets before they've been processed by IP.

I could write a driver that uses kernel udp sockets to generate a single message queue
than can be efficiently processed from userspace - but it is a faff compiling it for
the systems kernel version.

Well if destinations ports are not under your control,
you also could use AF_PACKET sockets, no need for 'UDP sockets' to receive UDP traffic,
especially it the rate is small.