558293 - Page almost unscrollable due to bad performance

Status: RESOLVED FIXED

(Core :: Layout, defect)

Description

[José Jeria]

Build ID: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.3a5pre) Gecko/20100408 Minefield/3.7a5pre

1. Go to http://crystal-castles.tumblr.com/
2. Scroll page once the images are loaded

Actual Results: almost unscrollable

Expected results: Smooth scrolling like Opera, Chrome and IE

Comment 1

[José Jeria]

Enabling Direct2D support just made the performance worser

Comment 2

[José Jeria]

Attachment: Image used by testcase

Comment 3

[José Jeria]

Attachment: Image used by testcase

Comment 4

[José Jeria]

Attachment: The testcase

Comment 5

[Boris Zbarsky [:bzbarsky]]

Yep.  Painting is expensive.  That said, d2d _should_ help this on supported hardware, and the layers work would also help...

Comment 6

[Robert O'Callahan (:roc) (email my personal email if necessary)]

This doesn't look like a painting problem to me. Scrolling by page-downs is actually quite fast. Scrolling by lines is slow. Presumably it's something to do with the way we break up the page into rects to be scrolled and rects to be ignored. Hopefully layer-based scrolling will fix this.

Comment 7

[José Jeria]

Maybe obvious, but removing the position:fixed on the left div makes scrolling smooth

Comment 8

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Ridiculously fast with retained layers.

Comment 9

[Ryan Jones-Ward [:sciguyryan]]

I can no longer see any performance issues on this page with the retained layers hourlies. If anyone feels this bug should be closed please do so.

Nice work roc!

Comment 10

[José Jeria]

Very smooth now! Fixed by 564991 I assume