scx/scheds/rust/scx_lavd
Andrea Righi cf4883fbf8 meson: introduce serialize build option
With commit 5d20f89a ("scheds-rust: build rust schedulers in sequence"),
schedulers are now built serially one after the other to prevent meson
and cargo from forking NxN parallel tasks.

However, this change has made building a single scheduler much more
cumbersome, due to the chain of dependencies.

For example, building scx_rusty using the specific meson target would
still result in all schedulers being built, because they all depend on
each other.

To address this issue, introduce the new meson build option
`serialize=true|false` (default is false).

This option allows to disable the schedulers' build chain, restoring the
old behavior.

With this option enabled, it is now possible to build just a single
scheduler, parallelizing the cargo build properly, without triggering
the build of the others. Example:

  $ meson setup build -Dbuildtype=release -Dserialize=false
  $ meson compile -C build scx_rusty

Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
2024-06-28 10:17:37 +02:00
..
src scx_lavd: optimizing deadline related tunables 2024-06-28 09:00:45 +09:00
.gitignore scx_lavd: Add .gitignore 2024-04-04 07:15:37 -10:00
build.rs scx_lavd: add scx_lavd (Latency-criticality Aware Virtual Deadline) scheduler 2024-03-16 10:31:07 +09:00
Cargo.toml Bump versions for a release 2024-06-03 08:35:21 -10:00
LICENSE scx_lavd: add scx_lavd (Latency-criticality Aware Virtual Deadline) scheduler 2024-03-16 10:31:07 +09:00
meson.build meson: introduce serialize build option 2024-06-28 10:17:37 +02:00
README.md scx_lavd: add scx_lavd (Latency-criticality Aware Virtual Deadline) scheduler 2024-03-16 10:31:07 +09:00
rustfmt.toml scx_lavd: add scx_lavd (Latency-criticality Aware Virtual Deadline) scheduler 2024-03-16 10:31:07 +09:00

scx_lavd

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_lavd is a BPF scheduler that implements an LAVD (Latency-criticality Aware Virtual Deadline) scheduling algorithm. While LAVD is new and still evolving, its core ideas are 1) measuring how much a task is latency critical and 2) leveraging the task's latency-criticality information in making various scheduling decisions (e.g., task's deadline, time slice, etc.). As the name implies, LAVD is based on the foundation of deadline scheduling. This scheduler consists of the BPF part and the rust part. The BPF part makes all the scheduling decisions; the rust part loads the BPF code and conducts other chores (e.g., printing sampled scheduling decisions).

Typical Use Case

scx_lavd is initially motivated by gaming workloads. It aims to improve interactivity and reduce stuttering while playing games on Linux. Hence, this scheduler's typical use case involves highly interactive applications, such as gaming, which requires high throughput and low tail latencies.

Production Ready?

This scheduler could be used in a production environment where the current code is optimized. The current code does not particularly consider multiple NUMA/CCX domains, so its scheduling decisions in such hardware would be suboptimal. This scheduler currently will mainly perform well on single CCX / single-socket hosts.