Prelink (or how to make KDE boot in 3 seconds)

Thus, let's imagine that we have a binary that depends on the QtCore library, once we have executed prelink on it, it will first search in the space designated by prelink, and in the event that it does not find it (an update, for example) it will search for it in the traditional way.

Prelink works on any POSIX compliant system, like GNU / linux or the BSDs.

How to apply prelink

Optimizing the system with prelink is quite simple, we can optimize a binary using (as root):

prelink binario

But to optimize the entire system we must perform:

prelink -amvR

You will see something like this:

pre-link

Here is a detailed explanation of the meaning of the parameters:

• a: equals –all, makes it apply to the whole system
• m: equivalent to –conserve-memory, the explanation of how it works is complex, but saves space
• v: equivalent to –verbose, it allows us to know which are the pre-linked libraries
• A: Equivalent to –random, increase security by making a value random. I do not know the details of its operation

To un-pre-link (unlink) a binary

prelink  -u

The whole system:

prelink -au

# Skype -b / usr / lib32 / skype / skype -b / usr / lib / skype / skype # Flash Player Plugin -b /usr/lib/mozilla/plugins/libflashplayer.so # NVIDIA -b / usr / lib / libGL .so * -b /usr/lib32/libGL.so* -b //usr/lib/libOpenCL.so* -b //usr/lib32/libOpenCL.so* -b / usr / lib32 / vdpau / -b / usr / lib / vdpau / -b /usr/lib/xorg/modules/drivers/nvidia_drv.so -b /usr/lib/xorg/modules/extensions/libglx.so* -b / usr / lib / libnvidia- * - b / usr / lib32 / libnvidia- * # Catalyst -b / usr / lib / libati * -b / usr / lib / fglrx * -b / usr / lib / libAMDXvBA * -b /usr/lib/libGL.so* - b / usr / lib / libfglrx * -b /usr/lib/xorg/modules/dri/fglrx_dri.so -b /usr/lib/xorg/modules/drivers/fglrx_drv.so -b / usr / lib / xorg / modules / extensions / fglrx / -b /usr/lib/xorg/modules/linux/libfglrxdrm.so -b /usr/lib/xorg/modules/extensions/libglx.so

Optimize KDE

What is promised is debt. If you had already pre-linked your system you probably didn't notice any difference in KDE loading times. This is so because KDE serves as a utility called kdeinit to load all the necessary libraries. To avoid using this tool we must let KDE know that it is pre-linked. To do this we must (as root) create a variable file:

nano /etc/profile.d/kde-prelink.sh

In which we paste the following line

export KDE_IS_PRELINKED=1

And we give it the proper permissions (we don't want any naughty to add rm-rf /)

chmod 755 /etc/profile.d/kde-prelink.sh

And if you don't believe me, here is a video of KDE booting up on my system:

• HDD at 7200 RPM
• Gentoo
• XFS
• Ksplash disabled (cause of video black screen

Cron and prelink

If you use a system like Archlinux, in which updates are very frequent, it might be interesting to add a cron that runs prelink every day.

Thus, we open the cron file with nano (as root):

nano /etc/cron.daily/prelink

And we paste the following:

#! / Bin / bash
[[-x / usr / bin / prelink]] &&
/ usr / bin / prelink -amR &> / dev / null

Then we give it the appropriate permissions (I already mentioned that nobody wants someone to add malicious code):
chmod 755 /etc/cron.daily/prelink

A good habit when reading an article is to research what exactly the script does. A good habit when writing it is to explain what it is for. Here the breakdown

Links of interest