1260215 - Scrolling on verily.com is stuttery/janky

Status: NEW

(Core :: Panning and Zooming, defect, P3)

Description

[(no longer active)]

Safari seems to be able to do a much more smooth job at scrolling https://verily.com/ than we can.

Comment 1

[Botond Ballo [:botond]]

Could you verify that the page is async-scrolling, for example by enabling paint flashing (nglayout.debug.paint_flashing) and verifying that the page isn't repainted on every scroll? If so, a profile would be helpful to understand the slowdown.

For me, testing on Linux, the page is async-scrolling, and my perception of the scrolling smoothness is fine (but I don't have Safari nearby to compare it to).

Comment 2

[Kartikaya Gupta (email:[e-mail])]

With paintflashing I see the background of the page (and many other parts) continuously repainting all the time, even if I'm not scrolling. OS X aurora build from March 17.

Comment 3

[Kartikaya Gupta (email:[e-mail])]

It's probably eating CPU unnecessarily as well.

Comment 4

[Kartikaya Gupta (email:[e-mail])]

Actually I'll file a new bug for the infinite painting, and mark this dependent on that. There might be more going on here, best to keep the issues separate.

Comment 5

[Markus Stange [:mstange]]

The infinite painting, combined with slow texture upload, are what's causing the stuttery scrolling. Texture upload happens on the compositor thread and blocks composition.

Comment 6

[Kartikaya Gupta (email:[e-mail])]

Trying to make sure all jank buga have "jank" in the summary.