Unofficial user repositories/Repo-ck

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Revision as of 19:21, 19 December 2012 by Graysky (talk | contribs) (Details)
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TL; DR Summary

Packages Provided:

CPU-Optimized Flavors:

  • Generic - Any x86_64 or i686 CPU.
  • Atom - Optimized packages for Intel Atom CPUs.
  • Core2 - Optimized packages for Intel C2D/C2Q CPUs.
  • Nehalem - Optimized packages for First Generation Intel Core i3/i5/i7 CPUs.
  • Sandybridge - Optimized packages for Second Generation Intel Core i3/i5/i7 CPUs.
  • Ivybridge - Optimized packages for Third Generation Intel Core i3/i5/i7 CPUs.
  • P4 - Optimized packages for Intel Pentium 4 CPUs.
  • Pentm - Optimized packages for Intel Pentium-M CPUs.
  • Kx - Optimized packages for AMD K7/K8/K10 CPUs.
  • Barcelona - Optimized packages for AMD Barcelona CPUs.
  • Bulldozer - Optimized packages for AMD Bulldozer CPUs.
  • Piledriver - Optimized packages for AMD Piledriver CPUs.

Setup: See the Repo-ck#Setup section below to enable and use the repo.


The repo contains generic packages as well as CPU-specific packages. Many ARCH users are familiar with the concept of a generic kernel package. The official ARCH 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 packages or CPU-specific and optimized linux-ck packages:


  • ck-generic ==> Compiled with generic optimizations suitable for any compatible CPU just like the official ARCH linux package. This is true for both Intel and AMD processors.


  • ck-atom ==> Intel Atom platform specific optimizations. Intel Atom CPUs have an in-order pipelining architecture and thus can benefit from accordingly optimized code.
  • ck-core2 ==> Intel Core 2-family including Dual and Quads (Core 2/Newer Xeon/Mobile Celeron based on Core2).
  • ck-nehalem ===> Intel 1st Generation Core i3/i5/i7-family specific optimizations.
  • ck-sandybridge ==> Intel 2nd Generation Core i3/i5/i7-family specific optimizations.
  • ck-ivybridge ==> Intel 3rd Generation Core i3/i5/i7-family specific optimizations.
  • ck-p4 ==> Intel Pentium-4 specific optimizations (P4/P4-based Celeron/Pentium-4 M/Older Xeon).
  • ck-pentm ==> Intel Pentium-M specific optimizations (Pentium-M notebook chips/not Pentium-4 M).
  • ck-kx ==> AMD K7 (Athlon/Athlon XP)/K8 (Athlon 64, Athlon 64 X2, 23xx Quad-Core Barcelona, Sempron, Sempron 64)/K10-family (Athlon X2 7x50, Phenom X3/X4, Phenom II, Athlon II X2/X3/X4, Sempron 64 [Socket AM3 only], 61xx Eight-Core Magny-Cours) specific optimizations. Enables use of some extended instructions, and passes appropriate optimization flags to GCC.
  • ck-barcelona ==> CPUs based on AMD Family 10h 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.

CPU-specific optimization are invoked at compilation by selecting the corresponding option under Processor type and features>Processor family or by setting-up the .config file accordingly. These changes setup make specific gcc options including the $CFLAGS.

Note: Repo packages include the BFQ I/O Scheduler compiled as a module. Read the section below for instructions to load it and enable it should you wish to do so.

[Graysky's public key] used for package signing. Pacman v4 will automatically query the public key server, but if users would rather download and manually add the key, do so from the link.


1) Add the following to /etc/pacman.conf (I placed my entry at the bottom of the file):

SigLevel = PackageRequired
Server =$arch

To sign graysky's key, do the following:

# pacman-key -r 5EE46C4C
# pacman-key --lsign-key 5EE46C4C

2) Refresh via pacman -Syy

That's it. To see the contents of the repo, just search as such:

$ pacman -Sl repo-ck

Installation Examples

Use the ck-X group and select the desired packages for installation. There are 6 groups corresponding to the 12 package sets: ck-generic, ck-atom, ck-core2, ck-nehalem, ck-sandybridge, ck-ivybridge, ck-p4, ck-pentm, ck-kx, ck-barcelona, ck-bulldozer, ck-piledriver

# pacman -S ck-generic
:: There are 7 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-ck
   6) virtualbox-ck-guest-modules  7) virtualbox-ck-host-modules

Enter a selection (default=all):

Alternatively, simply direct pacman to install the packages directly:

# pacman -S linux-ck linux-ck-headers

How to Determine Which CPU Optimized Package Set to Select

Users unsure which package set to use can always install the ck-generic group which will drive any compatible CPU. For those wanting CPU-specific optimized packages, run the following command (assuming that base-devel is installed):

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

The resulting value is what gcc would use as the march CFLAG. Refer to the table below for a mapping of this value to the correct group.

Brand March= Group
AMD barcelona ck-barcelona
bdver1 ck-bulldozer
bdver2 ck-piledriver
athlon, athlon-4, athlon-tbird, athlon-mp, athlon-xp ck-kx
Intel atom ck-atom
core2 ck-core2
corei7 ck-nehalem
corei7-avx ck-sandybridge
core-avx-i ck-ivybridge

Additional links can be used to help determine which package set to select:

How Much Faster Are the CPU Optimized Packages

The answer is not that much faster. Extensive testing comparing the effect of gcc compile options on resulting binaries have been conducted by others with varying result from no change to rather significant speed ups.

Readers are encouraged to add to this list.

How to Enable the BFQ I/O Scheduler

Since release 3.0.4-2, the BFQ patchset is applied to the package by default. Users must enable the BFQ scheduler to use it; it is dormant by default.

Globally (for all devices)

Add elevator=bfq to boot loader Kernel parameters.

Note: Users building the PKG from the AUR have an option in the PKGBUILD itself to globally use the BFQ as the default I/O scheduler.

Selectively (for only specified devices)

Direct the kernel to use it on a device-by-device basis. For example, to enable it for /dev/sda simply:

# echo bfq > /sys/block/sda/queue/scheduler

To confirm, simply cat the same file:

# cat /sys/block/sda/queue/scheduler
noop deadline cfq [bfq] 

Setting this way will not survive a reboot. To make the change automatically at the next system boot, create the following tmpfile where "X" is the letter for the SSD device.

w /sys/block/sdX/queue/scheduler - - - - noop

Package Trivia/Repo Statistics

  • Various package sets are compiled via a Bash wrapper script for makepkg. The script is publicly accessible at graysky's github repo.
  • Repo statistics are available (popularity of packages, which CPU is most popular, # of downloads, etc.).
Note: The statistics are not updated daily but do give a snapshot of the data.


Forum Support

Please use this discussion thread to voice comments, questions, suggestions, requests, etc. Note from graysky, "I can add other CPU-specific builds upon request. I just wanna be sure people will actually use them if I take the time to compile them."