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Repo-ck is an unofficial Arch Linux repository with generic and CPU-optimized kernels and support packages, featuring BFS (Brain Fuck Scheduler) and rest of the -ck patchset by Con Kolivas.


Add the repo-ck repository to pacman.conf and sign Graysky's key.

Kernels and related packages

Note: LTS packages are not included.

The official kernel is available in two flavors (either i686 or x86_64) which are generic packages, in that i686 will work with any compatible x86 CPU and x86_64 will work with any compatible x86_64 CPU. Users have a choice between the corresponding generic linux-ck package, or packages optimized for a specific CPU.

CPU-specific optimizations are invoked by selecting Processor type and features > Processor family in make menuconfig, or by adjusting .config accordingly. These changes setup make specific GCC options, including CFLAGS.

Packages marked with * are available only for the 64-bit systems, see this forum post.

CPU Type Group Alias Details
Generic ck-generic Generic kernel similar to the official Arch Linux kernel.
Intel ck-atom Intel Atom specific optimizations.
ck-silvermont * Intel Silvermont specific optimizations.
ck-core2 Intel Core 2-family including Dual and Quads.
ck-nehalem * Intel 1st Generation Core i3/i5/i7-family
ck-sandybridge * Intel 2nd Generation Core i3/i5/i7-family
ck-ivybridge * Intel 3rd Generation Core i3/i5/i7-family
ck-haswell * Intel 4th Generation Core i3/i5/i7-family
ck-broadwell * Intel 5th Generation Core i3/i5/i7-family
ck-skylake * Intel 6th Generation Core i3/i5/i7-family
ck-p4 Intel Pentium-4 (P4/P4-based Celeron/Pentium-4 M/Older Xeon).
ck-pentm Intel Pentium-M (Pentium-M notebook chips/not Pentium-4 M).
AMD ck-kx AMD K7/K8-family
ck-k10 * AMD K10-family including 61xx Eight-Core Magny-Cours, Athlon X2 7x50, Phenom X3/X4/II, Athlon II X2/X3/X4, or Turion II-family processor.
ck-bobcat * CPUs based on AMD Family 14h cores with x86-64 instruction set support.
ck-bulldozer * CPUs based on AMD Family 15h cores with x86-64 instruction set support.
ck-piledriver * CPUs based on AMD Family 15h cores with x86-64 instruction set support.

Selecting the correct CPU optimized package

When unsure, install the ck-generic group, which works with any compatible CPU. Those wanting CPU-specific optimized packages can run the following command (assuming that base-devel is installed):

$ gcc -c -Q -march=native --help=target | grep march

The resulting -march is what GCC would use natively. Refer to the table below for a mapping of this value to the correct group.

Warning: Intel CPU optimized packages support only full Core2 series and i3/i5/i7 series chips. Many Pentium/Celeron chips lack the full requisite instruction sets to make use of the optimized packages. Users of these chips should install the generic packages, even if GCC returns a value corresponding to full core i3/i5/i7 match such as haswell.
Note: This table has been updated to show the new simplified march options that ship with GCC v4.9+. For more information see the release notes.
Brand Group March
Intel ck-atom bonnell
ck-silvermont silvermont
ck-core2 core2
ck-nehalem nehalem
ck-sandybridge sandybridge
ck-ivybridge ivybridge
ck-haswell haswell
ck-broadwell broadwell
ck-skylake skylake
ck-p4 pentium4, prescott, nocona
ck-pentm pentm, pentium-m
AMD ck-kx athlon, athlon-4, athlon-tbird, athlon-mp, athlon-xp, k8-sse3
ck-k10 amdfam10
ck-bobcat btver1
ck-bulldozer bdver1
ck-piledriver bdver2
Note: Add additional entries to this table based on experience.

For further help, see:

Speed benefits of CPU optimized packages

Extensive testing comparing the effect of GCC compile options show varying results, from no change to rather significant speed ups. [1] [2] [3]

Tango-view-fullscreen.pngThis article or section needs expansion.Tango-view-fullscreen.png

Reason: Add results to this section where appropriate. (Discuss in Talk:Repo-ck#)

Installation examples

Note: As with any additional kernel, manually edit the boot loader configuration to make it aware of new kernel images. For example, see GRUB#Generate the main configuration file for GRUB.

Use the ck-X group and select the desired packages for installation. There are 11 groups corresponding to the package sets. For example:

# pacman -S ck-generic
:: There are 8 members in group ck-generic:
:: Repository repo-ck
   1) broadcom-wl-ck  2) linux-ck  3) linux-ck-headers  4) nvidia-304xx-ck  5) nvidia-340xx-ck  6) nvidia-ck

Enter a selection (default=all):

Alternatively, direct pacman to install linux-ck and linux-ck-headers.

BFQ I/O scheduler

See Linux-ck#How to enable the BFQ I/O Scheduler.

Repository statistics

Note: The statistics are not updated daily but do give a snapshot of the data.

Repo statistics are available (package and CPU popularity, number of downloads, and so forth).


There is at least one mirror available:



Please use the BBS thread.

Downloads interrupt regularly

Graysky is using Go Daddy as his web host. Some of the transfers from their poorly implemented server end in an incomplete transfer. To combat this, list the repository address multiple times and pacman will automatically try the next available server. As repo-ck has only one address (no mirrors), use the same server line:

Server =$arch
Server =$arch
Server =$arch
Server =$arch
Server =$arch

Alternatively, change the pacman downloader to wget, which automatically resumes downloads.

See this forum post for an explanation of these issues.

Error: signature from "graysky (used to sign repo-ck packages) <>" is unknown trust

You must import and sign graysky's gpg keys. Instructions along with his key ID are located at See also Pacman/Package signing#Adding unofficial keys.