Re: About performance issue when moving windows around with metacity.

[Elijah Newren <newren gmail com>]

On 2/8/06, Martin Holt Juliussen <mjuliuss online no> wrote:
> Hello
>
> After using all of the GNOME -versions from 2.10 to 2.13 (including a
> lot of dev-versions) I have been annoyed with the fact that when I move
> windows around, it uses a lot of the CPU time.

You'd need to quantify "lots of CPU time", in particular by profiling.
 But I don't think this is the main problem you were actually worried
about...

> The consequence of this
> is of course that the icons of the backgrounds disappears while I am
> dragging and a lot garbage is left in other windows. I have a
> understanding for this, since the programs which are active (I suppose
> it is the windows manager in this case) is prioritized over those who
> are idle.

No, it's because updates aren't synchronized.  The WM draws window
border decorations; that's it.  Other apps are responsible for
re-drawing their own window areas when they become exposed again.  But
X is basically setup so these don't all happen at the same time,
resulting in artifacts all over the place.  The fix is to use X
extensions, like composite, in a compositing manager (which
realistically needs to be part of the window manager).  We happen to
have two under development -- Novell went off and wrote their own
("compiz") which hasn't been released it yet, while Soeren's working
on one in Metacity which other contributors have joined (or at least
said they were going to...).


Hope that helps,
Elijah