mirror of
https://github.com/sched-ext/scx.git
synced 2024-11-28 21:50:23 +00:00
32 lines
1.6 KiB
Markdown
32 lines
1.6 KiB
Markdown
|
# scx_lavd
|
||
|
|
|
||
|
|
This is a single user-defined scheduler used within [sched_ext](https://github.com/sched-ext/scx/tree/main), which is a Linux kernel feature which enables implementing kernel thread schedulers in BPF and dynamically loading them. [Read more about sched_ext](https://github.com/sched-ext/scx/tree/main).
|
||
|
|
|
||
|
|
## 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.
|
||
|
|
|