[PATCH xserver] FlushAllOutput: Only call FlushCallbacks when actually flushing data

[Michel Dänzer]

On 08.07.2016 19:01, Michel Dänzer wrote:
> From: Michel Dänzer <michel.daenzer at amd.com>
> 
> The unnecessary FlushCallback calls could cause significant performance
> degradation with compositing.
> 
> As an example, with the radeon driver using glamor, a gtkperf run using
> default parameters (100 iterations of every test) takes:
> (numbers without => with this patch)
> 
> * About 1.9 => 1.9 seconds with xfwm4 without compositing
> * About 2.6 => 2.2 seconds with compton compositing added
> * About 4.1 => 2.2 seconds with kwin compositing
> * About 10.2 => 2.4 seconds with xfwm4 compositing
> 
> Signed-off-by: Michel Dänzer <michel.daenzer at amd.com>

I'm retracting this patch in favour of
https://patchwork.freedesktop.org/patch/102509/ .


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer