EXA patches

[Michel Dänzer]

On Mon, 2009-08-03 at 20:09 +0200, Maarten Maathuis wrote:
> 2009/8/3 Michel Dänzer <michel at daenzer.net>:
> > On Mon, 2009-08-03 at 18:56 +0200, Maarten Maathuis wrote:
> >> There is one thing that did change, driver pixmaps are not allocated
> >> by default (only when exa deems acceleration doable). So for dri2
> >> pixmaps you would need to create a scratch pixmap and attach a bo
> >> afterwards.
> >
> > That doesn't sound like a very nice solution. Maybe
> > exaGetPixmapDriverPrivate() could call the driver CreatePixmap(2) hook
> > if there is no private yet, but I'm not sure offhand what should happen
> > if that returns NULL then.
> 
> I have something in mind which would work nicely, except if it's
> 1bpp/4bpp (since they are classified as useless to accelerate)

Well, I think it's more that the offscreen memory / migration code just
can't deal with bpp < 8 yet. We may want to fix that at some point if
there's still hardware which can use any such formats.

> or if the driver fails to return something useable, is that ok?

Can't say without seeing it. :)


> >> About the performance, i didn't notice that, but we (nouveau) place
> >> pixmaps in vram from the moment it's created, [...]
> >
> > So does the radeon driver I'm using. So you're not seeing the slowdown
> > with nouveau?
> 
> A minor slowdown, maybe 1% is observed. They all fall into the range
> of 472K-477K, the first being the lowest value for mixed, the latter
> the highest value for !mixed. Often it's 473K vs 475K.

You're saying all three tests give similar numbers for you? If so, your
bottleneck seems to be on the vertex path, the middle test only cranks
out about 2/3 of the others here because the glyphs are much larger.

I wonder if maybe the slowdown I'm seeing is because the radeon driver
is temporarily lacking UploadToScreen and DownloadFromScreen hooks with
KMS, though I'm not sure what those would be used for with text
rendering.


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