[Interest] Slow graphics effect (due to _dl_resolve_runtime_avx)

[Allan Sandfeld Jensen]

On Saturday 26 November 2016, Ch'Gans wrote:
> So something tells me that, for some reasons, the drop shadow is
> repainted way too many times, yet the app on the screen is updated
> only once every second or so.
> 
> Maybe the event loop is going crazy recursive or something like that?
> 
Or the shadow could just be really expensive to calculate - which it is, and 
as far as I know it isn't being terribly clever either, so it just does an 
expensive blur on the entire source without trying to minimize the area 
processed. Using it on anything non-trivial in size is inadvisable.

 Did you check how many times QPixmapDropShadowFilter::draw()  was called?

Btw. If you have big cycles in valgrind, you can add --separate-callers (=2 
for instance) to the valgrind command line, so it will break more cycles 
automatically.

`Allan