Bug#553417: when turning of composite_manager in gconf the whole display freezes

[Sjoerd Simons]

On Mon, Nov 16, 2009 at 01:39:08PM +0100, Josselin Mouette wrote:
> Le lundi 16 novembre 2009 à 11:45 +0000, Will Thompson a écrit : 
> > This is because gnome-wm chooses mutter over metacity if direct
> > rendering is supported. I don't think this is a good choice. As I
> > understand it, mutter is not really meant to be used in its own right;
> 
> Yes it is, it's a drop-in replacement for metacity.

It might be a drop-in replacement, it's more of a tech demo then anything else.
Most focus on Mutter is currently to build other stuff on top of (such as
gnome-shell and the moblin shell), the default behaviour is clearly not very
polished and quite annoying from time to time.

> > moreover, if you're using an Intel graphics chip without kernel
> > mode-setting enabled, Mutter draws approximately one frame per second
> > (due to a Clutter bug, I believe).
> 
> That is more problematic. If you have an idea how to detect this case,
> I???m all for adding the detection code to gnome-wm.

You can't really. The problem is a bug in the Intel driver where without KMS
its sync to vblank will sync to the external output even if that's not
connected. It just happens to be polled about once a second to see if there is
a monitor attached, otherwise you wouldn't even 1fps :)

I expect that most users get mutter as a dependency from gnome-shell, not
because they want to use it directly.

My suggestion would be to have to change the WM order in gnome-we to
[ metacity, sawfish, mutter ] instead of the the current
[ mutter, metacity, sawfish].

This means that people that do really want mutter to replace metacity can just
install mutter and purge metacity or set mutter as WINDOW_MANAGER. Which
probably means that it does the right thing for a bigger group then it does
now (even if you ignore the people where mutter doesn't work because of
graphics driver bugs in the first place)

  Sjoerd
-- 
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Only one feat is possible -- not to have run away.
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