This document discusses techniques for improving the performance of Linux systems, including prelinking and hashstyling. Prelinking resolves library references ahead of time to reduce program startup times. Hashstyling involves compiling software with new binutils and glibc features enabled to further improve dynamic linking speeds. The document provides instructions for setting up prelinking and hashstyling on different distributions like Gentoo and describes some potential issues and workarounds.

1. Hashstyling &Prelinks
Horsepower your Linux system

2. What “distro” do you use?
 Ubuntu
 Slackware
 Debian
 Fedora
 BSD!!
 Gentoo!!!!!

3. Is your box sleepy!!
 If you have to wait for a program to start then you
better be using windows……..
 How much time does KDE or Firefox take to load??
 Let’s give some power pills to your box
I look sick!!!
Nah

4. Here are the pills……
 Hastyling
• you got to compile to hash style, preferably Gentoo
or BSD
 Prelinks
 Will work on any distro, but 64bit will be voila…

5. What are Prelinks???
 Well there are libraries to be loaded at startup of a
program…
 Most of them are shared with other programs
 Thus a lot of symbolic references needs to be
resolved while startup.
 This is fast for smaller programs, but
 For programs like open office and Firefox- Pain
 My open office writer takes 20sec to load before
prelinking and 11 after….
 Firefox takes <3 in place of 9
 Not to mention KDE loading at all( you time that)

6. Prelinks drawbacks
 You need to re-prelink every time you update your
libraries or anything.
 Size of executables increases( just penalty on space
though)
 It’s static. Libraries are bonded to the executables, It
doesn’t work with dynamically loaded libraries
 So, the improvement in programs like open office is
far lesser…
 Don’t worry…… Just keep following

7. Doing it with style: Hashstlye
 The new improvement in binutils and glibc called
direct linking or –Bdirect is the next improvement in
the field of faster computing.
 Careful… It’s still under development and not
officially adopted.
 With Hashstyling people(l33t ones!!) have seen 50%
improvements in dynamic linking , as in load times
 All of this is owing to new improvements in the new
DT_GNU_HASH or gnu.hash. The older version was
.hash.

8. How to prelink?
 It’s basically same in all distros
 Emerge or apt-get or yast or yum anything you use
 Just install “prelink”
 Run this command
 #prelink –amfRv
 a = all packages
 m = Conserve the virtual memory space
 f = force linking
 R = Random – randomize the address ordering, this
enhances security against buffer overflows.
 v = I won’t tell that( no price for guessing either!)

9. Enhance KDE
 What you did on the last page was good enough to
see the power, but some more tweaking is no harm
 Set KDE_IS_PRELINKED=quot;truequot; in
/etc/env.d/*kdepaths* to inform KDE about the
prelinking.
 Prelink cronjob: Set it up as a cron job, if you keep
updating your libraries
 Generally not required for quarterly updaters

10. Just in case : if you don’t like it
 To remove prelinks:
 Remove the prelink cronjob
 Run $prelink –au
 Just uninstall it as you do for any other software
 Gentooers $ emerge –aC prelink
 And there are gentoo forums and irc channels to
discuss any meshups( and there will be!!) you
encounter

11. Hashstyling: Gentoo only
 Get THE latest version of binutils , glibc and
gcc(4.2+) .( edit package.keywords)
 Follow the steps in order:
 1) emerge binutils
 $ binutils-config -l
 $ binutils-config # (Replace # with the
corresponding number to binutils-2.17.50.0.3)
 $ emerge glibc

12. Edit make.conf
 Open /etc/make.conf and make this entry exactly
with NO SPACES what so ever.
 LDFLAGS=quot;-Wl,--hash-style=both“
 If you already use some LD flags, change them and
input these.
 Now we will rebuild the system with these new flags.
 $emerge –e world
 $emerge prelink
 $prelink –amfRv

13. Crosscheck
 Just run this on the executable you want to check
 $ readelf -a /usr/bin/nano | grep GNU_HASH
[ 4] .gnu.hash GNU_HASH 00000000004009a0 000009a0
0x000000006ffffef5 (GNU_HASH) 0x4009a0
More information on http://www.gentoo.org/doc/en/prelink-howto.xml
 Please ensure you are emerging binutils >=
2.17.50.0.3
 That’s it guys: You have a very fast system now,
but don’t go and mess with a “l33t” guy yet.
There are other ways of improving performance.

14. Upgrade from patch to newer version
 In case you have an old hashstyled system which
was based on patches then follow exactly, or good
luck restarting the whole process again
 Remove -Wl,--hash-style from LDFLAGS
 Get the latest overlay from the svn
 Run
 $ LD_X=1 emerge -1 coreutils binutils glibc
 Add -Wl,--hash-style=both to LDFLAGS again
 Run:
 $ LD_X=1 emerge -e world

15. Continued
 Emerge prelink
 Prelink –amfRv
 Do not turn off power during the whole process
 That’s it
 In case…..System crashed!! Rebuild or go dig
Gentoo forums
 I haven’t tested it, but a gentoo veteran have:
http://gentoo-wiki.com/User:Roderick

16. Gentoo hashstlye thread
 http://forums.gentoo.org/viewtopic-t-475538.html
 You may find the solutions to all your problems here,
 If you don’t post one….

17. Some glichy packages
 X11-drm
 Maadwifi-ng
 While compiling these packages just comment
LDFLAGS in make.conf

18. The next level……
 Hope you have your CHOST and CFLAGS and USE
flags right
 Don’t you dare use anything below i686
 Add “ –O2 –march=<your-cpu> -fomit-frame-pointer”
 MAKEOPTS =“-j?” Google for your processor
 If you arte having more than one system give a look
to distcc
 And ya ccache
 Above two will save a lot of compile time.

19. Wanna ask something…..
 I know you have lot of question, just throw them,
answer is NOT guaranteed 

20. If you have time go Gentoo…
Thanks!!!