1403993 - Janky scrolling on the xps15 on Windows

Status: NEW

(Core :: Graphics: Layers, defect, P2)

Description

[Nicolas Silva [:nical]]

Attachment: about-support.txt

Scrolling is horribly janky and the input latency is terrible too.

Here is a profile: https://perfht.ml/2xzIkUR

The compositor appears to be spending most of its time waiting for a previous composite to finish.

about:support in attachment.

Comment 1

[Nicolas Silva [:nical]]

The profile was collected by just scrolling around a simple MDN page

Comment 2

[Nicolas Silva [:nical]]

Another profile with advanced layers disabled: https://perfht.ml/2xAuQYJ

Still pretty bad, I feel like it's a tad better but it's still so bad that it's hard to tell.

Comment 3

[Nicolas Silva [:nical]]

Whatever is wrong is definitely "proportional" to the window area (if I tile it to half of the screen, scrolling becomes much smoother).

Comment 4

[Milan Sreckovic [:milan] (needinfo for best results)]

How are you scrolling (mouse, kbd, scrollbar, touch screen) and is this a regression?

Comment 5

[Nicolas Silva [:nical]]

Using two finger swipe to scroll. Scrolling on stable isn't smooth either, I don' t think it is a (recent) regression.

Comment 6

[Firefox Bug Husbandry Bot]

https://wiki.mozilla.org/Bug_Triage/Projects/Bug_Handling/Bug_Husbandry#Move_fix-optionals