EXA and MigrationHeuristic

[Alex Deucher]

On Wed, May 28, 2008 at 2:46 PM, Juliusz Chroboczek
<Juliusz.Chroboczek at pps.jussieu.fr> wrote:
> Dear all,
>
> After my recent adventures with Radeon, XAA and EXA, I've come to the
> conclusion that setting MigrationHeuristic to greedy drastically helps
> performance of Firefox redraws on both Radeon and i965GM hardware.
>
> By drastically, I mean it -- a redraw of a full-screen Firefox goes
> from 3 to 5 seconds (!) down to a fraction of a second.
>
> Now I haven't read the sources of Firefox (let him who has cast me the
> first stone), but I believe that Firefox performs client-side backing
> store using absolutely humonguous pixmaps.  While we may argue that
> what Firefox does is stupid, I think we should try to support this
> kind of usage.
>
> Isn't the default value of MigrationHeuristic incorrect ?  Should we
> switch to greedy as default ?  (Julien tells me that he believes that
> Ubuntu have already made the switch.)

The radeon driver in git is much improved, and there have been quite a
few notable improvements in the EXA core in xserver in git (notably
Owen's glyph stuff and the migration aging improvements).

Alex