[PATCH] exa: add EXA_MIXED_PREFER_UTS

[Michel Dänzer]

On Tue, 2009-12-01 at 17:20 +0100, Michel Dänzer wrote: 
> 
> I think PREFER_UTS is too specific. I'm working on similar changes e.g.
> in GetImage.
> 
> Note that these changes are motivated by a rather special environment
> where direct PrepareAccess isn't possible and DownloadFromScreen is very
> expensive. Maybe the name of the new flag should reflect that, and the
> previous behaviour be restored when the flag isn't set.

I just had an idea how we might even get away without a flag:

If the driver PrepareAccess hook succeeds for a pixmap, we can assume
that this will always be the case and thus destroy the system memory
copy and damage record altogether. Then in the paths in question
(Get/PutImage, ...) we can use UploadTo/DownloadFromScreen directly for
pixmaps which don't have a damage record. This might result in the first
such operation(s) on a given pixmap not taking the desirable path, but
in contrast to a flag it would choose the path per pixmap.

What do you think? I don't know when I'll get around to looking into
this though, feel free to beat me to it.


-- 
Earthling Michel Dänzer           |                http://www.vmware.com
Libre software enthusiast         |          Debian, X and DRI developer