They mention working on using io_uring for filesystem calls for 2021. I wonder if there will be an option to use io_uring (instead of epoll) for networking calls as well? Handling network packets and events completely in userspace should allow for lower latency due to no more context switches to and from the Kernel, right?

There's some interesting bits on the low-level work for using io_uring with the Ringbahn crate - https://boats.gitlab.io/blog/post/ringbahn/

Smerity

The author of sled[1], an embedded database in Rust which has a number of promising features, has also written parts of rio[2], an underlying pure Rust io_uring library, which is intended to become the core write path for sled. rio has support for files but also has a demo for TCP (on Linux 5.5 and later) and O_DIRECT.

I tested rio recently as I had a Brilliant but Bad Idea™ involving file access and was pleasantly surprised by the API, as I have been with sled's.

I'm excited for the experimentation in the Rust ecosystem and for such low level crates to handle the complex io_uring tasks (relatively) safely!

[1]: https://github.com/spacejam/sled

[2]: https://github.com/spacejam/rio