scx/scheds/rust/scx_rustland
Jake Hillion 8ca45cfa37
lint: enable cargo fmt (#643)
Use `cargo fmt` with a specific nightly branch in the CI to enforce formatting. Globally format these files while the diff is still small so we can stay on top of it.

Test plan:
- CI lint check passes.
2024-09-11 10:03:20 +01:00
..
src lint: enable cargo fmt (#643) 2024-09-11 10:03:20 +01:00
.gitignore build: Use workspace to group rust sub-projects 2024-08-25 00:47:58 -10:00
build.rs scx_rustland_core: introduce RustLandBuilder() 2024-02-28 17:49:44 +01:00
Cargo.toml scx_rustland_core: expose enq_flags to user-space 2024-09-06 11:25:24 +02:00
LICENSE scx_rustland: rename from scx_rustlite 2023-12-22 00:20:14 +01:00
README.md scx_rustland: update documentation 2024-02-28 17:49:44 +01:00
rustfmt.toml scx_rustland: rename from scx_rustlite 2023-12-22 00:20:14 +01:00

scx_rustland

This is a single user-defined scheduler used within sched_ext, which is a Linux kernel feature which enables implementing kernel thread schedulers in BPF and dynamically loading them. Read more about sched_ext.

Overview

scx_rustland is made of a BPF component (scx_rustland_core) that implements the low level sched-ext functionalities and a user-space counterpart (scheduler), written in Rust, that implements the actual scheduling policy.

How To Install

Available as a Rust crate: cargo add scx_rustland

Typical Use Case

scx_rustland is designed to prioritize interactive workloads over background CPU-intensive workloads. For this reason the typical use case of this scheduler involves low-latency interactive applications, such as gaming, video conferencing and live streaming.

scx_rustland is also designed to be an "easy to read" template that can be used by any developer to quickly experiment more complex scheduling policies fully implemented in Rust.

Production Ready?

Not quite. For production scenarios, other schedulers are likely to exhibit better performance, as offloading all scheduling decisions to user-space comes with a certain cost.

However, a scheduler entirely implemented in user-space holds the potential for seamless integration with sophisticated libraries, tracing tools, external services (e.g., AI), etc.

Hence, there might be situations where the benefits outweigh the overhead, justifying the use of this scheduler in a production environment.

Demo

scx_rustland-terraria

The key takeaway of this demo is to demonstrate that , despite the overhead of running a scheduler in user-space, we can still obtain interesting results and, in this particular case, even outperform the default Linux scheduler (EEVDF) in terms of application responsiveness (fps), while a CPU intensive workload (parallel kernel build) is running in the background.