Is XAA still supported in recent and future xserver?

[Luc Verhaegen]

On Mon, Sep 13, 2010 at 09:18:12AM -0600, Matt Dew wrote:
> On Mon, Sep 13, 2010 at 8:37 AM, Alex Deucher <alexdeucher at gmail.com> wrote:
> > On Mon, Sep 13, 2010 at 10:29 AM, Matt Turner <mattst88 at gmail.com> wrote:
> >> On Mon, Sep 13, 2010 at 4:06 AM, Marc Scherer <marc.scherer at mp-ndt.de> wrote:
> >>> We are using the siliconmotion video driver and the performance on a
> >>> xserver dated June 2009 was better with XAA than with EXA.
> >>>
> >>> Since I am just starting again to work on the driver: will XAA be
> >>> available and supported in the near future?
> >>>
> >>> Thanks for comments,
> >>>
> >>> Marc
> >>
> >> Yeah, XAA is still there. Too many older DDXs only support XAA to
> >> think about removing it.
> >>
> >
> > That said, it's not seen active development in years and has
> > bit-rotted in a number of areas resulting in various bits of
> > functionality being disabled (offscreen pixmaps for example).
> >
> > Alex
> >
> >> Matt
> 
> Is that something that should go on a TODO (wish)list?  Move remaining
> DDXs from XXA to EXA? Maybe improve those drivers' performance on EXA
> first?

Well, sadly people have been working hard on making a direct comparison 
between XAA and EXA impossible, but at the time when that was still 
possible, XAA beat EXA quite consistently.

Intel actively pushed, despite fierce opposition from some linux 
enterprise desktop distributor, the removal of XAA support code for the 
intel driver stack. Plus, active mutilation of XAA also took place (1), 
officially to clean up stuff, but it actively took away a good fast path 
for XAA, and got us into code paths where gpu and cpu were not synced 
properly, as that code previously was never hit in an unsynced state 
(2).

If the benchmarks are not improving for one, make them degrade for the 
other, or remove the possibility for comparisons to be made.

Luc Verhaegen.

(1) http://cgit.freedesktop.org/xorg/xserver/commit/?id=e4d11e58
(2) http://cgit.freedesktop.org/xorg/xserver/commit/?id=59f9fb4b