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This because each scheduler has it's own Rust Crate and it's better if they had a README associated with each one. https://crates.io/crates/scx_layered
38 lines
1.7 KiB
Markdown
38 lines
1.7 KiB
Markdown
# scx_layered
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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).
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## Overview
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A highly configurable multi-layer BPF / user space hybrid scheduler.
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scx_layered allows the user to classify tasks into multiple layers, and apply
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different scheduling policies to those layers. For example, a layer could be
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created of all tasks that are part of the `user.slice` cgroup slice, and a
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policy could be specified that ensures that the layer is given at least 80% CPU
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utilization for some subset of CPUs on the system.
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## How To Install
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Available as a [Rust crate](https://crates.io/crates/scx_layered): `cargo add scx_layered`
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## Typical Use Case
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scx_layered is designed to be highly customizable, and can be targeted for
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specific applications. For example, if you had a high-priority service that
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required priority access to all but 1 physical core to ensure acceptable p99
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latencies, you could specify that the service would get priority access to all
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but 1 core on the system. If that service ends up not utilizing all of those
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cores, they could be used by other layers until they're needed.
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## Production Ready?
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Yes. If tuned correctly, scx_layered should be performant across various CPU
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architectures and workloads.
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That said, you may run into an issue with infeasible weights, where a task with
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a very high weight may cause the scheduler to incorrectly leave cores idle
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because it thinks they're necessary to accommodate the compute for a single
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task. This can also happen in CFS, and should soon be addressed for
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scx_layered.
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