Re: GUADEC Hacking

[David Zeuthen <david fubar dk>]

On Mon, 2005-04-11 at 21:59 -0400, Havoc Pennington wrote:
> On Mon, 2005-04-11 at 19:09 +0100, Jamie McCracken wrote:
> > yes we know its disk seeks that are causing the problem and secondly 
> > GConf is the most disk intensive service at start up and lastly due to 
> > its design of having loads of files that need to be read. Put all three 
> > together...
> 
> I'm a little skeptical because IIRC the mail I posted with the
> gconf-on-startup profiling numbers only showed 2-3 seconds for GConf.
> Which is worth fixing, but by no means explains the entire login time.
> 
> A good place to start for full data would be the "boot chart" profiles
> people have done.

Right. According to my experiments documented here (which also covers
logging into a GNOME 2.8 desktop)

 http://www.redhat.com/archives/fedora-devel-list/2004-November/msg01374.html

things look much much better when disk caches are primed before login,
data is laid out in sequential order and the footprint is low (no pun
intended :-). Most of these issues, except memory footprint and
minimizing disk seeks, are really nasty OS specific problems in their
own right and probably out of the scope of GNOME proper. 

Interestingly enough, implementing things such as disk defrag and sane
readahead (a'la Windows XP and Mac OS X) may actually help mask the root
problems we're seeing right now. So we better work on them before it's
too late :-)

Cheers,
David