Re: Multiple issues with wallpaper handling

[Chris Dekter <cdekter gmail com>]

A bit of an update...

I tested running mutter directly, however as I don't know how to (or 
whether you can) get the overview animation running without shell 
running, it seems kind of moot. The problem is only noticeable during 
the overview animation. Having said that, running raw mutter I saw no 
problems.

I definitely do think there is a (highly selective) bug here, as some 
Googling showed someone else on this list a few weeks ago with exactly 
the same symptoms. I've run my testing on 5 different hardware platforms 
now, and the conclusion I'm reaching is that it must be some kind of 
interaction between shell/mutter and the open radeon drivers. Running 
two monitors exacerbates the problem (due to bigger memory requirements 
I'm guessing), but it occurs to a lesser extent with one monitor as 
well. My testing platforms:

- Radeon 5750 with open drivers - fails test case
- Radeon 5850 with open drivers - fails test case
- nVidia 8600GT with binary drivers - no problems
- nVidia GTX550 with binary drivers - no problems
- Intel i3 with HD 2000 graphics (Sandy Bridge) - no problems

Of these, all but the last one were the same box just swapping out the 
graphics card. Different kernel versions, different Xorg driver versions 
had no effect (within the limited range of what I could test without 
making the system unbootable).

I'm very willing to do more testing if anyone wants to tackle this 
problem - even if it's just to determine that the problem lies in the 
Radeon open driver. I'm a software QA engineer by trade so I'm sure I 
could do an adequate job of testing this :) Gnome Shell is such a 
fantastic environment and I'd be very happy to be able to make what 
small contribution I can.

On 02/12/11 13:10, Jasper St. Pierre wrote:
> Does the issue exist if you run raw mutter? I can't reproduce the
> issue here with mutter or with gnome-shell. There's no performance dip
> if I lock the screen or change the wallpaper.
>
> The code that handles the wallpaper is here:
>
>      http://git.gnome.org/browse/mutter/tree/src/compositor/meta-background-actor.c
>
> You can see that it tries very hard to make sure that it's not holding
> onto the pixmap any more than it needs to.