Install sched_ext

Install the scheduler tools and check that your kernel supports sched_ext. The package manager and repository instructions depend on your distribution.

Choose your distribution

Choose the instructions for your distribution. Use the release package, scx-scheds, for everyday use rather than a Git build.

Devario (Shelly)

Install from devario-core. You do not need a development repository.

1. Check your repository configuration. Devario uses Shelly and /etc/shelly.conf. If you need to add the repository, follow the devario-core setup page for its signing key and current configuration. See native repository configuration for Shelly configuration details.

2. Update your system and install scx-scheds.

   shelly upgrade standard
   shelly install standard scx-scheds polkit

Arch-based (pacman)

Use your distribution’s repositories and /etc/pacman.conf, not Shelly’s configuration. On Arch, the release package is available from the official repositories; you do not need to add a Devario development repository.

sudo pacman -Syu scx-scheds polkit

The Arch package and the Devario fork can contain different tools. Check for scxcli and scxtui before following the switching instructions. If either is missing, use the upstream catalog installation instructions for your release instead. Do not assume a Devario repository is compatible with another distribution.

polkit supplies pkexec, which the tools need for switching as a normal user. It may already be installed with your desktop.

Check your running kernel and the tools

This workflow requires systemd and /bin/bash, plus the packaged scx.service, /etc/default/scx, /usr/share/scx/catalog.json and polkit policy. The supplied policy expects scxcli at /usr/bin/scxcli. Installing the binaries with Cargo alone does not install these supporting files.

test -d /sys/kernel/sched_ext && echo "sched_ext available"
test -x /usr/bin/scxcli && echo "scxcli installed"
command -v scxtui
/usr/bin/scxcli list
/usr/bin/scxcli get

The first command should print sched_ext available. If it does not, boot a kernel with sched_ext support before continuing. Check that the tools are found and scxcli list loads the catalog before following the switching steps. scxtui finds its helper programs through systemd’s default binary search path, not custom additions to your shell’s PATH. state: default (kernel scheduler) is normal when no scx scheduler is running.

Development builds

scx-scheds-git follows development rather than a release. Use it only if you want to test development changes, not as the default installation. Choose one scx repository and follow its setup page:

• devario-scx: upstream main, without extra scheduler backports.
• devario-scx-dev: scheduler backports not yet merged upstream; also offers linux-devario-dev.

Both contain Git builds and can introduce regressions. Install scx-scheds-git instead of scx-scheds, not alongside it. Review any package replacement prompt before proceeding.

Next, choose and start a scheduler.