Everything Open 2024 Quick Notes :: Day 1

Talks, EverythingOpen, rxlog

sched_ext - Write your own Linux thread scheduler in BPF #

BPF made creating new scheduler simpler
- with strong safety guarantee to not break the system, the side effects of bad scheduler are confined.
- run a binary to enable your scheduler, stop the binary to revert to default
Scheduling problem is now more complicated due to increasing complexity of workload/CPU design
BPF provides reliable access to critical data structures inside the kernel

Forked from n2n to avoid CLA
- Protocol level compatibility with n2n is maintained
Peer-to-peer VPN at network layer, acting like a distributed virtual switch
- Layer 2 over Layer 3
- Only route packets through a server/supernode when required, p2p by default
- Better latency due to being p2p
NAT piecing
Written in C, should have good cross-platform supports (more testing wanted on *BSD)
- Relatively small codebase for a VPN
TunTap interface support is expected from the OS side, shouldn’t be a problem for common Unix-likes
- Modern macOS is dropping support for TunTap, need to use NetworkExtension?
Packaging and distro submission are still WIP
- Framework for a debian package exists but not in an upstreamable shape
- OpenBSD?
Future roadmap
- n3n over IPv6
- Code cleanup
- Multiple network driver support (e.g. something other than TunTap)
- Better NAR piecing
- Mobile support?
Useful for
- LAN gaming with old/modern systems
- Remote access
Simpler than wireguard/openvpn but offers OK security (not for security-critical apps?)
Easier to configure, use INI style config files

seL4 is bad at usability, Lions OS intends to solve this
Still in early stage of development
Composable components for build custom OS for a single task
- Runs on seL4 Microkernel
- For things like IoT, embedded, cars etc…
Focus on simplicity
0.1.0 just released, still in its early stage
high performance
Only for Arm64/aarch64 now, riscv64 in future?
Device Driver Model
Multi Language Support
A reference system called Kitty exists
- A Linux running inside VMM is used for framebuffer, but any OS should do