PsyCachy Kernel

This repository contains the releases of the linux-psycachy kernel, and the script for building that and custom variants. The script may automate the process of configuring and optimizing the kernel build according to your hardware and preferences.

For those on GitHub

This is a mirror of the official repository in which this project is active. If you wish to contribute, consider heading there instead to be credited in the contributors.

What's this about?

PsyCachy is a kernel with improved settings for compatibility and stability across Debian/Ubuntu Linux distributions derived from linux-cachyos. Releases are made targeting Ubuntu rolling and LTS with dkms module compatibility, since it's the most widely used version, but you are free to build it for other kernel versions and distributions for yourself like Debian using the proto branch.

Differences to linux-cachyos

• Built with gcc, as clang caused too many inconsistencies due to llvm bugs.
• Doesn't include processor architecture-specific optimizations, as they bring too small gains to justify the time compiling them or the confusion caused to newcomers by multiple kernel versions on release - you can include those by building the kernel yourself running cachyos-deb.sh with -b option if you wish.
• Doesn't include handheld console drivers, as there isn't much of a point on doing it for Debian/Ubuntu.
• OS/-o2 optimization instead of -o3, which caused quite a few problems with Debian/Ubuntu packages. Now it builds -o3 by default, fixed.

Recommended usage (for most people)

Install the kernel image of your choice from Releases or through LinuxToys.

Manual installation

• Download all three .deb packages
• Open terminal in the same directory of the packages
• sudo dpkg -i linux-image-psycachy_6.14.11-1_amd64.deb linux-headers-psycachy_6.14.11-1_amd64.deb linux-libc-dev_6.14.11-1_amd64.deb, replacing 6.14.11 with your package version
• To install CachyOS SystemD configuration files as well to maximize effectiveness, download and run cachyconfs.sh available from Releases or LinuxToys.

Secure Boot

You can make the kernel compatible with Secure Boot by signing it using create-key.sh available from Releases. Remember to store the password you set when the keypair is created carefully as it will be required to import the MOK into BIOS.

Building

Prerequisites

Before running the script, ensure you have the following prerequisites installed:

• libncurses-dev gawk flex bison openssl libssl-dev dkms libelf-dev libudev-dev libpci-dev libiberty-dev autoconf llvm gcc rustc: for compiling the kernel.
• whiptail: For displaying dialog boxes in the script.
• curl: For fetching the latest kernel version.
• devscripts and debhelper: For packaging.

You can install these dependencies using your distribution's package manager, or have the build scripts install them for you. It is advisable to use Ubuntu LTS or Debian Stable for building to ensure better compatibility. You can use a docker, podman or distrobox container for that.

Features

The builder in proto offers a variety of configuration options:

• Auto-detection of CPU architecture for optimization.
• Selection of CachyOS specific optimizations.
• Configuration of CPU scheduler, LLVM LTO, tick rate, and more.
• Support for various kernel configurations such as NUMA, NR_CPUS, Hugepages, and LRU.
• Application of O3 optimization and performance governor settings.

Usage

To use the script to build your own kernel, follow these steps:

1. Clone the repository to your local machine.
2. Make the script executable with chmod +x cachyos-deb.sh.
3. Run the script with ./cachyos-deb.sh.
4. Follow the on-screen prompts to select your desired kernel version and configurations, for:
   • Choose the kernel version.
   • Enable or disable CachyOS optimizations.
   • Configure the CPU scheduler, LLVM LTO, tick rate, NR_CPUS, Hugepages, LRU, and other system optimizations. You may want to check the Advanced Configurations section for more details on these options.
   • Select the preempt type and tick type for further system tuning.
5. Compile and install.

Launch options (for cachyos-deb.sh on proto branch)

• -b: builds a psycachy-variant kernel with optimizations specific to your CPU MARCH.
• -g: builds a psycachy generic image from the latest kernel upstream release.
• -l: builds a psycachy-lts generic image from the latest LTS kernel upstream release.

Advanced Configurations

The script includes advanced configuration options for users who want to fine-tune their kernel:

• CachyOS Configuration: Enable all optimizations from CachyOS. A kernel with this option enabled is not guaranteed to work.
• CPU Scheduler: Choose between different schedulers like Cachy, PDS, or none.
• Tick Rate: Configure the kernel tick rate according to your system's needs.
• NR_CPUS: Set the maximum number of CPUs/cores the kernel will support.
• Hugepages: Enable or disable Hugepages support.
• LRU: Configure the Least Recently Used memory management mechanism.
• O3 Optimization: Apply O3 optimization for performance improvement.
• Performance Governor: Set the CPU frequency scaling governor to performance.
• Modprobed.db: will use the database built from modprobed.db to only build drivers specific to your machine. WARNING: use the default kernel with modprobed.db up and running for at least a week before building with this option to make sure all drivers you need are on the database, and always keep a default (or psycachy generic package) kernel as a backup!

Contributing

Contributions are welcome! If you have suggestions for improving the script or adding new features, please open an issue or submit a pull request.

License

This project is licensed under the MIT License as upstream - see the LICENSE file for details.