linux-tkg

This repository provides scripts to automatically download, patch and compile the Linux Kernel from the official Linux git repository, with a selection of patches aiming for better desktop/gaming experience. The provided patches can be enabled/disabled by editing the customization.cfg file and/or by following the interactive install script. You can also use your own patches (more information in customization.cfg file).

Important information

• Non-pacman distros support can be considered experimental. You're invited to report issues you might encounter with it.

• If your distro isn't using systemd, please set _configfile="running-kernel" in customization.cfg or you might end up with a non-bootable kernel

• In intel_pstate driver, frequency scaling aggressiveness has been changed with kernel 5.5 which results in stutters and poor performance in low/medium load scenarios (for higher power savings). As a workaround for our gaming needs, we are setting it to passive mode to make use of the acpi_cpufreq governor passthrough, keeping full support for turbo frequencies. It's combined with our aggressive ondemand governor by default for good performance on most CPUs while keeping frequency scaling for power savings. In a typical low/medium load scenario (Core i7 9700k, playing Mario Galaxy on Dolphin emulator) intel_pstate in performance mode gives a stuttery 45-50 fps experience, while passive mode + aggressive ondemand offers a locked 60 fps.

• Nvidia's proprietary drivers might need to be patched if they don't support your chosen kernel OOTB: Frogging-Family nvidia-all can do that automatically for you.

• Note regarding kernels older than 5.9 on Arch Linux: since the switch to zstd compressed initramfs by default, you will face an invalid magic at start of compress error by default. You can workaround the issue by editing /etc/mkinitcpio.conf to uncomment the COMPRESSION="lz4" (for example, since that's the best option after zstd) line and regenerating initramfs for all kernels with sudo mkinitpcio -P

Customization options

Alternative CPU schedulers

CFS is the only CPU scheduler available in the "vanilla" kernel sources. Its current implementation doesn't allow for injecting additional schedulers, and requires replacing it. Only one scheduler can be patched in at a time.

Alternative schedulers are available to you in linux-tkg:

• Project C / PDS & BMQ by Alfred Chen: blog, code repository
• MuQSS by Con Kolivas : blog, code repository
• CacULE by Hamad Marri: code repository
• Undead PDS: TkG's port of the pre-Project C "PDS-mq" scheduler by Alfred Chen. While PDS-mq got dropped with kernel 5.1 in favor of its BMQ evolution/rework, it wasn't on par with PDS-mq in gaming. "U" PDS still performs better in some cases than other schedulers, so it's been kept undead.

These alternative schedulers can offer a better performance/latency ratio for gaming and desktop use. The availability of each scheduler depends on the chosen Kernel version: the script will display what's available on a per-version basis.

Default tweaks

• Memory management and swapping tweaks
• Scheduling tweaks
• CFS tweaks
• Using the "Cake" network queue management system
• Using vm.max_map_count=16777216 by default
• Cherry-picked patches from Clear Linux's patchset

Optional tweaks

The customization.cfg file offers many toggles for extra tweaks:

• Fsync and Futex2(deprecated) support: can improve the performance in games, needs a patched wine like wine-tkg
• Graysky's per-CPU-arch native optimizations: tunes the compiled code to to a specified CPU
• Compile with GCC or Clang with optional O2/O3 and LTO (Clang only) optimizations.
  • Warning regarding DKMS modules prior to v3.0.2 (2021-11-21) and Clang: DKMS version v3.0.1 and earlier will default to using GCC, which will fail to build modules against a Clang-built kernel. This will - for example - break Nvidia drivers. Forcing older DKMS to use Clang can be done but isn't recommended.
• Using Modprobed-db's database can reduce the compilation time and produce a smaller kernel which will only contain the modules listed in it. NOT recommended
  • Warning: make sure to read thoroughly about it first since it comes with caveats that can lead to an unbootable kernel.
• "Zenify" patchset using core blk, mm and scheduler tweaks from Zen
• Anbox support (See Anbox usage)
• ZFS FPU symbols (<5.9)
• Overrides for missing ACS capabilities
• Provide own kernel .config file
• ...

User patches

To apply your own patch files using the provided scripts, you will need to put them in a linux5y-tkg-userpatches folder -- y needs to be changed with the kernel version the patch works on, e.g linux510-tkg-userpatches -- at the same level as the PKGBUILD file, with the .mypatch extension. The script will by default ask if you want to apply them, one by one. The option _user_patches should be set to true in the customization.cfg file for this to work.

Anbox usage

As of kernel 5.18, ashmem was dropped, breaking anbox. Their old Android 7 base doesn't allow moving to memfd so it might take a while to fix. The newer WayDroid alternative moved to using memfd thanks to an easier to work with Android 10 base. It still depends on binderfs, which is supported on 5.18+, but ashmem isn't a requirement for it anymore. An ashmem dkms driver can be used to circumvent the issue, but it currently is problematic on 5.19 and is likely to require active maintenance going forward. If you can, consider moving to WayDroid.

When enabling the anbox support option, the binder and ashmem modules are built-in. You don't have to load them. However you'll need to mount binderfs :

sudo mkdir /dev/binderfs
sudo mount -t binder binder /dev/binderfs

To make this persistent, you can create /etc/tmpfiles.d/anbox.conf with the following content :

d! /dev/binderfs 0755 root root

After which you can add the following to your /etc/fstab :

binder                         /dev/binderfs binder   nofail  0      0

Then, if needed, start the anbox service :

systemctl start anbox-container-manager.service

You can also enable the service for it to be auto-started on boot :

systemctl enable anbox-container-manager.service

You're set to run Anbox. If you prefer automatic setup you can install anbox-support from AUR which will take care of everything by itself.

Install procedure

For all the supported linux distributions, linux-tkg has to be cloned with git. Since it keeps a clone of the kernel's sources within (linux-src-git, created during the first build after a fresh clone), it is recommended to keep the cloned linux-tkg folder and simply update it with git pull, the install script does the necessary cleanup at every run.

Arch & derivatives

git clone https://github.com/Frogging-Family/linux-tkg.git
cd linux-tkg
# Optional: edit the "customization.cfg" file
makepkg -si

The script will use a slightly modified Arch config from the linux-tkg-config folder, it can be changed through the _configfile variable in customization.cfg. The options selected at build-time are installed to /usr/share/doc/$pkgbase/customization.cfg, where $pkgbase is the package name.

Note: the base-devel package group is expected to be installed, see here for more information.

DEB (Debian, Ubuntu and derivatives) and RPM (Fedora, SUSE and derivatives) based distributions

Important notes:

• Some issues have been reported by both Fedora (see Frogging-Family#383) and Ubuntu (see Frogging-Family#436) users where stock kernels cannot boot any longer, the whereabouts are still not entirely clear (it does not seem to affect every user)
  • Ubuntu: appears to be an initramfs generation issue
  • Fedora: needs disabling then re-enabling SELINUX so one can boot

The interactive install.sh script will create, depending on the selected distro, .deb or .rpm packages, move them in the the subfolder DEBS or RPMS then prompts to install them with the distro's package manager.

git clone https://github.com/Frogging-Family/linux-tkg.git
cd linux-tkg
# Optional: edit the "customization.cfg" file
./install.sh install

Uninstalling custom kernels installed through the script has to be done manually. install.sh can can help out with some useful information:

cd path/to/linux-tkg
./install.sh uninstall-help

The script will use a slightly modified Arch config from the linux-tkg-config folder, it can be changed through the _configfile variable in customization.cfg.

Void Linux

git clone -b tkg https://github.com/Hyper-KVM/void-packages/
cd void-packages
./xbps-src binary-bootstrap
# Optional: edit customization.cfg located in srcpkgs/linux-tkg/files
# Optional: add custom userpatches with the ".mypatch" extension to srcpkgs/linux-tkg/files/mypatches
./xbps-src pkg -j$(nproc) linux-tkg

If you have to restart the build for any reason, run ./xbps-src clean linux-tkg first.

Generic install

The interactive install.sh script can be used to perform a "Generic" install by choosing Generic when prompted. It git clones the kernel tree in the linux-src-git folder, patches the code and edits a .config file in it. The commands to do are the following:

git clone https://github.com/Frogging-Family/linux-tkg.git
cd linux-tkg
# Optional: edit the "customization.cfg" file
./install.sh install

The script will compile the kernel then prompt before doing the following:

sudo cp -R . /usr/src/linux-tkg-${kernel_flavor}
cd /usr/src/linux-tkg-${kernel_flavor}
sudo make modules_install
sudo make install
sudo dracut --force --hostonly --kver $_kernelname $_dracut_options
sudo grub-mkconfig -o /boot/grub/grub.cfg

Notes:

• All the needed dependencies to patch, configure, compile or install the kernel are expected to be installed by the user beforehand.
• If you only want the script to patch the sources in linux-src-git, you can use ./install.sh config
• ${kernel_flavor} is a default naming scheme but can be customized with the variable _kernel_localversion in customization.cfg.
• _dracut_options is a variable that can be changed in customization.cfg.
• The script uses Arch's .config file as a base. A custom one can be provided through _configfile in customization.cfg.
• The installed files will not be tracked by your package manager and uninstalling requires manual intervention. ./install.sh uninstall-help can help with useful information if your install procedure follows the Generic approach.

Gentoo

The interactive install.sh script supports Gentoo by following the same procedure as Generic, symlinks the sources folder in /usr/src/ to /usr/src/linux, then offers to do an emerge @module-rebuild for convenience

git clone https://github.com/Frogging-Family/linux-tkg.git
cd linux-tkg
# Optional: edit the "customization.cfg" file
./install.sh install

Notes:

• If you're running openrc, you'll want to set _configfile="running-kernel" to use your current kernel's defconfig instead of Arch's. Else the resulting kernel won't boot.
• The script will prompt for using llvm-libunwind, it can only work with the llvm-libunwind USE flag in sys-devel/clang but it is experimental:
  • Manual intervention is needed on the net-fs/samba EBUILD, see here
  • The -unwind USE flag is needed in app-emulation/wine* EBUILDs