1013297 - Quadtree Art 5x faster in Chrome, bottlenecked on BuildDisplayList/ProcessDisplayItems

Status: NEW

(Core :: Layout, defect)

Description

[Benoit Girard (:BenWa)]

Testcase: http://www.michaelfogleman.com/static/quads/

Profile: http://people.mozilla.org/~bgirard/cleopatra/#report=0c06855454b4be38c74c4b8c05172ba948ec5e43

(Ignore profile tail)

Comment 1

[Matt Woodrow (:mattwoodrow)]

Looks like this is creating a massive number of nsDisplaySVGPathGeometry objects, each individually wrapped in an inactive nsDisplayTransform. The overhead of processing all these inactive layer trees is hurting us a lot.

The transforms all have both a scale and a translation.

This would be a really good candidate for folding SVG display items together, adding jwatt to the cc list.

Comment 2

[Mayank Bansal]

with retain-dl, we are now roughly 3x slower than chrome.
Anything more that can be done here?

Comment 3

[Matt Woodrow (:mattwoodrow)]

Not particularly from the display list side, display list building is ~2ms now.

We're still pretty slow on layer building, and doing canvas readback (looks like the canvas is WebGL). There's also a lot of overhead painting the svg display items.