[Oneiric-Topic] LightDM for display management

[Robert Ancell]

On 04/08/2011 07:42 PM, Milan Bouchet-Valat wrote:
> Le vendredi 08 avril 2011 à 19:04 +0930, Jason Warner a écrit :
>> Thanks for proposing this. I'm particularly interested in any and all
>> speed improvements that could come from this...and if we have less
>> overhead in general, great!
> If you're using GNOME, loading a whole GNOME session when starting GDM
> won't induce much overhead, since you'll need to load all of those apps
> and libraries anyway in the login phase. It might even be better to read
> those files early since it makes sure ureadahead will catch them.
>
> And it ensures that once you've typed your password, the login is fast
> (less disk reads): since at that point we know you're sitting in front
> of your keyboard, better spend less time in that phase, and more in the
> boot per se.
>
> Of course only testing can decide which one is faster, but (for GNOME
> users) I don't think that's a priori so obvious.
There is additional overhead in that you have to initialize the GNOME
session twice, once for the gdm user and once for the user who logs in. 
And loading a session just to display ~10 fairly simple UI elements
seems like a huge waste.  I don't know enough about ureadahead, but it
certainly should cache the gnome-session libraries etc, perhaps we have
to whitelist them somewhere?

So I think in theory it should be faster.