Xorg 7.0-rc1 and EXA (radeon 9200)

[Stephane Marchesin]

On Wed, Oct 26, 2005 at 06:26:50PM +0200, Michel D?nzer wrote:
> 
> > > I agree with Ben that a way for the X server to reserve a couple of 
> > > physical surface registers (as opposed to virtual surfaces, which can 
> > > be merged by the DRM) would be a good solution for this problem.
> > 
> > Well, look at the memory allocation policy between ddx and dri : it's
> > ilt upon the same "reservation" kind of thinking, and the dri
> > performance suffers a lot from that.
> 
> There's no question that's bad, people are working on the unified memory
> manager to fix that. I don't agree that the situation with surfaces is
> all that similar though. What kind of surface usage in clients do you
> anticipate that would make it critical that clients can get 8 as opposed
> to 5 physical surfaces?
>

Well, there are mutiple reasons : multiple X servers and pbuffers are
the two I can think of right now.

> > But doing the same with surfaces, you'fre just reproducing the same
> > error...
> 
> But it's better to hurt X server performance by requiring up to 6 ioctls
> per software fallback to allocate and free virtual surfaces? I wonder
> how much time a typical user spends using X vs. GL.
>

I think you're making a mistake here. It's not about trying to
prioritize one over the other, but trying to get both cooperate.
As you probably now, this is major pain for radeon dri developers, 
since the radeon ddx assumes in lots of places that it's the only one 
in the world and takes no care when overwriting stuff.

Stephane