Discussion about combreloc and kde3 performance

[Collins]

For those of you who may be interested in improving kde3 performance,
I'm enclosing the following from a discussion on gentoo about
combreloc which is the new replacement for object pre-linking.  In
prior mails, the instructions for enabling combreloc were given, i.e.

	1) upgrade to binutils 2.12+ (we in gentoo land have 2.12.90.0.7
available.
	2) reinstall glibc (we in gentoo land have 2.2.5+)
	3) reinstall qt, kde, etc. to take advantage of combreloc

As noted below, this is alpha/beta software, so proceed with caution.

I have done this on my machine with no failures, but YMMV.  If it
works, you heard it here.  If it smokes your system, you got it from
some troll. <grin>


On Sun, 12 May 2002 20:35:15 -0700 Casey <cjv99 at shaw.ca> wrote:
> On 05 02, 20:45, Collins wrote:
> > OK, some more questions abount combreloc
> > 
> > 1) Just to verify - this is now automatically active once you have
> > binutils-2.12+ and you relink packages?

> Yes. combreloc does help cache the relocations, but it's also meant
> to allow for future prelinking. I'm gonna look into this on Gentoo..
> after midterms.

> > 2) I don't have anything super big like kde.  I did remerge xfree,
> > and maybe the x server starts a little faster.  galeon and the
> > latest mozilla were emerged after the binutils, and I don't notice
> > much
> Did you also remerge glibc?
[ answer: I did]
> > difference with them.  Is the performance difference supposed to
> > be at initial program load or subsequent reload?

> C programs don't benefit nearly as much (if at all) as C++ programs
> with tens of thousands of relocations.  Mozilla, Galeon, X..all C
> programs :) I've noticed that first launches are still somewhat
> unacceptable (though better), but the subsequent ones should be
> nearly instant (for me they are). 

[ I don't remember what kind of a machine he is using for the
comparison.]

> Before the new binutils: 
> konqueror first launch: 5 seconds
> konqueror subsequent launches: approx. 2 seconds
> konqueror page loads: (sometimes fast..sometimes 2-3 second delay)
> 
> After new binutils (and glibc):
> konqueror first launch: 2-3 seconds
> konqueror subsequent launch: < 0.25 seconds (faster than IE6 on
> Win2k) konqueror page loads: much faster than IE6..almost instant
> (fast Canadian cable modems!)

> > 3) Since you need to relink everything after the binutils upgrade,
> > is the effect permanent, i.e. do you need to repeat the process if
> > you upgrade binutils again?

> No, but binutils-2.12 is beta and changing constantly, so its good
> to keep an eye on it and update when necessary. But no, you don't
> lose the effects.

-- 
Collins Richey - Denver Area - WWTLRD?
gentoo(since 01/01/01) 2.4.19+(ext3) xfce-sylpheed-mozilla