slow startup needs performance profiling

[Jeff Fortin Tam]

GNOME Do 0.8 (and previous versions as well) starts up really slowly, even on warm starts. To reproduce:
- start gnome-do, wait for it to load
- logout from gnome
- login into gnome
- notice that all gnome components have loaded in <5 seconds, the computer seems idle
- keep hitting win+space repeatedly until gnome-do finally proves that it is ready* and appears (which takes >10 seconds on my WMD computer).

I would not have noticed this if it wasn't for the fact that it should be near-instantaneous on a warm login. Do surely is doing too much work for nothing.

*: ready is defined as "I can see the GUI and start typing to launch apps quickly"

Further reference for your convenience:
    * http://ftp.belnet.be/mirrors/FOSDEM/2007/FOSDEM2007-ProfilingDesktopApplication.ogg
    * http://www.gnome.org/~federico/docs/2005-GNOME-Summit/html/index.html
    * http://www.gnome.org/~federico/docs/2006-GUADEC/how-much-faster/index.html

[Alex Launi (alexlauni)]

Why do you think it should be nearly instantaneous on a warm login?

--
--Alex Launi

[Jeff Fortin Tam (kiddo)]

Because that generic phenomenon seems to apply to all other apps I've seen... I mean, if even gnome's horrible login (20-30 seconds on cold start) can start in 5 seconds warm, surely gnome-do can start in 1-2 seconds flat. This kind of persistently slow startup is telling me there must be something wrong. Even openoffice writer starts in 2-5 seconds (without the quicklauncher) after having been launched once and then closed.

According to Federico's arguments, most of performance problems are due to excess work. This was indeed the case for specto (http://jeff.ecchi.ca/blog/?p=634) which, after analysis, went from a 10+ seconds warm startup to a <2 seconds startup time.

For the record, I am running Do without any plugins active (I just use it as an application launcher).

[David Siegel (djsiegel-deactivatedaccount)]

I get Do to cold or warm start in a little under a second (with plugins enabled). All of the startup-time work that Do does is run on worker threads, so I believe the Gtk loop idles pretty much immediately. Do you have an extraordinarily slow disk or old machine?

[Jeff Fortin Tam (kiddo)]

Not that I know of, this is a quadcore with a SATA2 drive:

 Timing cached reads: 3322 MB in 2.00 seconds = 1661.17 MB/sec
 Timing buffered disk reads: 320 MB in 3.02 seconds = 106.12 MB/sec

Have you tried logging out and back in, with gnome-do on gnome session autostart?