DAMN prelinking is gooood!

really · Guru Joined: 27 Aug 2002 Posts: 430 Location: nowhere

uish! it blows me off!
you got to have it.
i just finished the emergement of my system, took 32hours something and just kde 26h.
if you want speed you MUST have prelinking!

didnt belive ti will be this fast.
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pjp · Administrator Joined: 16 Apr 2002 Posts: 20067

Moved from Portage & Programming.
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ballardb · Posted: Sun Feb 02, 2003 12:11 am Post subject:

I must admit I have just pre-linked my system and I really cannot see any difference.
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darktux · Posted: Sun Feb 02, 2003 1:47 am Post subject:

gsfgf · Veteran Joined: 08 May 2002 Posts: 1266

noff · Posted: Sun Feb 02, 2003 2:48 am Post subject:

I had the same experience. I'm hoping that when I reinstall and recompile everything that it produces a notica;e speed up as a lot of things don't prelink currently.
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nbensa · Posted: Sun Feb 02, 2003 2:59 am Post subject:

Bah, prelinking isn't what they promise... Did I read something like 40% 50% speed loading increase? Maybe that's true in an slow box, but mine is a P31G and can hardly see any difference.

Lowspirit · Posted: Sun Feb 02, 2003 4:31 pm Post subject:

I actually noticed a slowdown, don't know if it was my overly optimized cflags (with which everything is compiled) and the fact that I run Gnome, or why, but Linux all of a sudden felt like Windows, the HDD began to load like crazy for a simple task like opening a terminal.

I now have switched cflags to Os from 03, and alot less extra fluff params, my system runs alittle better with these flags but best of all is that all binaries are alot smaller so I'm hoping to try prelinking again sometime in the future, haven't given up.

After XFree 4.3 final is out i'll give prelinking a retry.
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sgaap · Posted: Sun Feb 02, 2003 8:32 pm Post subject:

I only noticed a real improvement with kde (on my relatively slow 1ghz), the rest of my system hasnt gained as much form prelinking..

kraylus · l33t Joined: 07 Jun 2002 Posts: 648 Location: ft.worth.tx

i was under the impression that prelinking only made it so that shared libs aren't redundantly loaded for two apps that use the same lib. for example, if you load mozilla at startup, it'll take the same amount of time as normal, but if you load another app later that uses the mozilla libs, it'll load a bit faster because moz is already using the libs and the newcoming app doesn't have to look for them first.

so yeah, for small garbage like xchat, gaim, etc. it wont make any difference. also keep in mind... it doesn't make the app RUN faster... just load faster. maybe im wrong, i dunno. anyone want to field this one?

ryan
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kraylus · l33t Joined: 07 Jun 2002 Posts: 648 Location: ft.worth.tx

idl · Posted: Sun Feb 02, 2003 11:13 pm Post subject:

prelinking works by turning your dynamic binarys into static ones. When you load a binary file that depends on some libs it goes and fetches the resources from these libs, they are external to the binary. Prelinking trys to find out what libs a dynamic binary needs, gathers all the info and builds it into the binary giving you a staticly linked binary file. Now when the binary is executed it doesnt have to go and fetch the stuff it needs from the libs because its allready built in.

kraylus · l33t Joined: 07 Jun 2002 Posts: 648 Location: ft.worth.tx

Matje · Posted: Mon Feb 03, 2003 12:28 am Post subject:

It does increase the size a bit. You can return to the original file by doing prelink -u
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Evangelion · Posted: Mon Feb 03, 2003 7:41 am Post subject:

Matje · Posted: Mon Feb 03, 2003 10:44 am Post subject:

Yeah, prelinked binaries have a little extra code in the beginning of the file which enables the prelinking stuff...
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BigRedDot · n00b Joined: 29 Oct 2002 Posts: 67 Location: Austin

Matje · Posted: Mon Feb 03, 2003 3:15 pm Post subject:

What prelinking does is, it checks if there is already is an instance of a library loaded in the memory, if so, it doesn't load it again, but instead just "links" the application to that instance, resulting in a faster startup.
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bradcarter · n00b Joined: 12 Nov 2002 Posts: 53

Does prelinking then reduce overhead? Instead of having multiple instances run of a library you only have one?

emmCee · n00b Joined: 04 Jan 2003 Posts: 20 Location: York, UK

Prelinking works by calculating various stuff (like the linking tables) once, and storing these calculations in the binary. It does _not_ staticly link the binaries, thus the extra size taken is minimal.

The speedup takes place because far fewer calculations must be done at run time when the binary is loaded and linked with the libraries. As such it takes place the first time you run the binary/the libraries are loaded and every consecutive time. Libraries already loaded into memory are shared implicitly anyway (that's one of the great things about shared libraries!).

There's a page here http://objprelink.sourceforge.net/howto.html that explains the ins and outs of prelinking if you're interested (its for a slightly older variant of the system, but the core ideas remain the same).

Prelinking on very highly-shared software like KDE will make a difference on every (current) machine, simply because linking does, in fact, take ages.

Even on my Athlon XP 2100 3/4GB DDR 333 the difference is very pronounced.

For an absolute measurement of loading/linking time for those people that don't believe me, try doing:

jufoa · Posted: Tue Feb 04, 2003 7:00 pm Post subject:

prelinking speeded up my kde applications startup times _a lot_

line72 · Apprentice Joined: 13 Jun 2002 Posts: 212

how often do yo uhave to run prelink ? If I upgrade kde do I need to re-run prelink or does portage take care of that for me ?

/Line72

AngusYoung · Posted: Fri Feb 21, 2003 8:02 pm Post subject:

Man, it really make a diference for me!!! Thanks for the advice

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darktux · Posted: Fri Feb 21, 2003 8:32 pm Post subject: