Difference between revisions of "Linux-pf"

Revision as of 18:51, 15 September 2013

Linux-pf is a kernel package based on the stock -ARCH kernel, patched with a row of significant patches:

• The latest Con Kolivas' -ck patchset, including BFS
• TuxOnIce
• BFQ (as default I/O scheduler)
• UKSM
• AUFS3

Installation

The reference PKGBUILD can be found at the linux-pf^AUR and at the bitbucket.org mercurial repository.

From the unofficial repository (recommended)

Precompiled packages, generic and CPU-family optimized are uploaded at the pfkernel unofficial repository, usually within 6 hours of the AUR update for x86_64 and 12 hours for i686. Append the following to /etc/pacman.conf to activate the pfkernel repo:

[pfkernel]
# Generic and optimized binaries of the ARCH kernel patched with BFS, TuxOnIce, BFQ, IMQ, Aufs3
# linux-pf, kernel26-pf, gdm-old, nvidia-pf, nvidia-96xx, xchat-greek, arora-git
Server = http://dl.dropbox.com/u/11734958/$arch

Running $ pacman -Syyl pfkernel will update all repos and show the available packages from pfkernel. Afterwards, just install linux-pf linux-pf-headers, but additional configuration steps must be performed; see the Installation section.

Manual compilation

There's a number of options a user is asked to choose from, should he/she select to compile from the PKGBUILD:

==> Hit <Y> to use your running kernel's config
    (needs IKCONFIG and IKCONFIG_PROC)
==> Hit <L> to run 'make localmodconfig'
==> Hit <N> (or just <ENTER>) to build an all-inclusive kernel like stock -ARCH
    (warning: it can take a looong time)

The <Y> option is for users who have already compiled and are running a custom kernel. The PKGBUILD reads the running kernel's configuration and uses it for the subsequent compilation. The <L> option tries some kind of autodetection of the user's hardware: it first tries to use the modprobed_db module database, then falls back to the linux kernel's make localmodconfig functionality. The last option is self-explanatory.

==> Kernel configuration options before build:
    <M> make menuconfig (console menu)
    <N> make nconfig (newer alternative to menuconfig)
    <G> make gconfig (needs gtk)
    <X> make xconfig (needs qt)
    <O> make oldconfig
    <ENTER> to skip configuration and start compiling

Choose one of these to use your favourite user interface for configuring the kernel. Note that the last option might still prompt with unresolved/new configuration options, if you have selected <Y> or <L> in the previous step.

==> An non-generic CPU was selected for this kernel.
==> Hit <G>     :  to create a generic package named linux-pf
==> Hit <ENTER> :  to create a package named after the selected CPU
                   (e.g. linux-pf-core2 - recommended)
==> This option affects ONLY the package name. Whether or not the
==> kernel is optimized was determined at the previous config step.

If you have selected a specific CPU optimization for your kernel in the previous step, the default action is to append the CPU to the package name. This way, a subsequent package update from the repository will pull the optimized package and not the generic one. This also will help better compatibility with 3rd party precompiled modules (e.g. nvidia-pf), which might break things if loaded on optimized linux-pf kernels.

Install compiled package

After the compilation finishes, an additional linux-pf-headers[-cpu] package will be created. Don't forget to install it too, if you plan on using additional modules like nvidia or virtualbox.

# pacman -U linux-pf-core2-3.3.2-1-$CPUTYPE.pkg.tar.xz linux-pf-headers-core2-3.3.2-1-$CPUTYPE.pkg.tar.xz

During the kernel installation, mkinitcpio will be called by the install script to recreate the initramfs.

Configuration

Then, you need to add a boot entry in boot loader configuration file which points to linux-pf (the following example is from one of the maintainer's boxes):

title  Linux-pf 3.2
root   (hd0,4)
kernel (hd0,0)/vmlinuz-linux-pf root=/dev/disk/by-label/ROOT ro vga=0x318 lapic resume=/dev/disk/by-label/SWAP video=vesafb:ywrap,mtrr:3 fastboot quiet
initrd (hd0,0)/initramfs-linux-pf.img

If you intend to use TuxOnIce for hibernation, make sure you have added the necessary modules to the MODULES array of /etc/mkinitcpio.conf and at least the resume hook to the HOOKS array:

MODULES="... lzo tuxonice_compress tuxonice_swap tuxonice_userui ..."
HOOKS="... block userui resume filesystems ..."

In the example above, TuxOnIce is setup to use a swap partition as the suspended image allocator. The resume hook must be placed before filesystems. Also, a progress indicator is requested with userui. Please read the TuxOnIce wiki page for more detailed information.

Last, you must choose whether you want to suspend using pm-utils or the hibernate-script. Please, refer to the respective wiki pages for more details. TuxOnIce offers the option for a text mode or an even nicer framebuffer splash progress indicator.

Tips and tricks

• If you notice disk-related performance problems or occational hickups, it might be an I/O scheduler issue. Try a different one than the linux-pf default (BFQ) by echoing to /sys/block/sda/queue/scheduler cfq, noop or deadline: # echo noop >. Note, the aforementioned command only sets the I/O scheduler for the 1st hard drive and additional echoes will be needed if you have more. If the situation improves, then append "elevator=cfq" (or noop or deadline) to the linux-pf command line in /boot/grub/menu.lst, to make the change permanent.
• For people who build their own tailored kernels and compilation aborts with with an error about "missing include/config/dvb/*.h files", setting <M> at DVB for Linux at Device Drivers/Multimedia support and leaving everything else out, creates just the necessary dvb.h, which allows the compilation to continue.

Forum thread for linux-pf

There's a discussion thread at the BBS for reporting errors, impressions, ideas and requests.

See also

• linux-pf mercurial repository
• Patchset homepage
• Patchset community forum
• Patchset changelog