Playing with Prelink

[Texstar]

prelink is a free program written by Jakub Jelínek of Red Hat for POSIX-compliant operating systems, principally Linux (because it modifies ELF executables). It is intended to speed up a system by reducing the time a program needs to begin. Actual results have been mixed, but it seems to aid systems with a large number of libraries, such as KDE.

1. Install prelink from Synaptic Package Manager

2. Open terminal konsole su to root and type /usr/sbin/prelink -avmR

3. While still in terminal edit /usr/bin/startkde with your favorite text editor. Add the line highlighted in bold to startkde.

export KDE_NO_IPV6=True
export KDE_USE_IPV6="no"
export KDE_IS_PRELINKED=1

Save the file and exit.

4. Reboot and see if your applications launch faster.

Security Bonus: prelink is capable of randomly selecting the address base that libraries are loaded at. This makes it more difficult to perform a return-to-libc attack on the system, because the addresses used are unique to that system.

* Not responsible if this causes your system to crash and burn. *

[Old-Polack]

This was a great post... until the last line. 

[gseaman]

Time to burn my system!

Galen

[Texstar]

I've noticed Firefox and Thunderbird are quicker to start on my system course it could be a jedi mind trick. Still playing...

[gseaman]

I have no scientific verification, but it seems faster. And nothing burned. I guess I can go to bed now.

Galen

[smcs_steve]

No difference here on FF.....   but some other apps do appear faster to launch.
I like the security aspect though.
>Steve

[pinoc]

applied to fullmonty and applications seem to start a bit snappier now.
Don't know if this is critical but while running  "/usr/sbin/prelink -avmR " I got this:

Code: [Select]

[root@localhost ~]# /usr/sbin/prelink -avmR
/usr/sbin/prelink: "/usr/bin/unetbootin" has no section headers
/usr/sbin/prelink: /usr/bin/fglrx_xgamma: Could not find one of the dependencies     
/usr/sbin/prelink: /usr/bin/q4wine-cli: Could not find one of the dependencies
/usr/sbin/prelink: /usr/bin/jahshaka: section file offsets not monotonically increasing
/usr/sbin/prelink: /usr/bin/q4wine: Could not find one of the dependencies
/usr/sbin/prelink: /usr/bin/q4wine-helper: Could not find one of the dependencies   
/usr/sbin/prelink: /usr/bin/xara-extreme: section file offsets not monotonically increasing
/usr/sbin/prelink: /usr/games/gltron: Could not find one of the dependencies         
/usr/sbin/prelink: /usr/lib/R/bin/exec/R: Could not find one of the dependencies
/usr/sbin/prelink: /usr/lib/pokerth-0.7.1/pokerth: Could not find one of the dependencies
/usr/sbin/prelink: /usr/lib/celtx/celtx-bin: Could not find one of the dependencies 
/usr/sbin/prelink: /usr/lib/googleearth/googleearth-bin: Could not find one of the dependencies
/usr/sbin/prelink: /usr/lib/kompozer/xpcshell: Could not find one of the dependencies
/usr/sbin/prelink: /usr/lib/kompozer/kompozer-bin: Could not find one of the dependencies
/usr/sbin/prelink: /usr/lib/kompozer/TestGtkEmbed: Could not find one of the dependencies
/usr/sbin/prelink: /usr/lib/torcs/torcs-bin: Could not find one of the dependencies 
/usr/sbin/prelink: /usr/lib/torcs/trackgen-bin: Could not find one of the dependencies
/usr/sbin/prelink: /usr/lib/torcs/texmapper-bin: Could not find one of the dependencies
/usr/sbin/prelink: /usr/lib/torcs/accc-bin: Could not find one of the dependencies   
/usr/sbin/prelink: /usr/lib/torcs/nfsperf-bin: Could not find one of the dependencies
Laying out 1268 libraries in virtual address space 41000000-50000000
Random base 0x44968000
/usr/sbin/prelink: Could not find virtual address slot for /usr/lib/grass64/lib/libgrass_sim.so
[root@localhost ~]#


[AndrzejL]

It should be:

Code: [Select]

dbus-launch kwrite /usr/bin/startkde
Rebooting.

Andy

[Texstar]

It should be:

Code: [Select]

dbus-launch kwrite /usr/bin/startkde
Rebooting.

Andy

An advanced user would know that! 

[AndrzejL]

It should be:

Code: [Select]

dbus-launch kwrite /usr/bin/startkde
Rebooting.

Andy

An advanced user would know that!  

Sowwy... ! Feel free to remove my post !

Can't prove it but it feels snappier...

Andy

EDIT: Woah... Was I just called an advanced user by Texstar himself?! WOW!

[menotu]

My KMenu opens really fast - it now opens immediately (before there was a very slight "hesitation") and Dolphin is opening folders with lots of files in them a lot quicker.

Useful little tweak.

[Texstar]

I can see the difference a lot more when launching applications in a non-kde desktop such as enlightenment.

[Old-Polack]

I can see the difference a lot more when launching applications in a non-kde desktop such as enlightenment.

Unless you changed something else in the last batch of upgrades, I just noticed, after running prelink and rebooting, that my GUI screen came back up on tty7 again, after being on tty8 since the earlier big batch of upgrades. 

[Hootiegibbon]

It should be:

Code: [Select]

dbus-launch kwrite /usr/bin/startkde
Rebooting.

Andy

An advanced user would know that!  

Sowwy... ! Feel free to remove my post !

Can't prove it but it feels snappier...

Andy

EDIT: Woah... Was I just called an advanced user by Texstar himself?! WOW!

Andy,

He wasn't saying that, what my interpretation would be is

Andy, an advanced user would know that, without resorting to a search first.... lol

I jest of course.

I have noticed an increase in responsiveness, cool stuff Texstar!  

EDIT further reading for those interested http://linux.die.net/man/8/prelink

Jase

[menotu]

EDIT further reading for those interested http://linux.die.net/man/8/prelink

Nice link Jase - many thanks