1448509 - Slow scrolling when opacity is applied to lots of fixed backgrounds

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, defect, P1)

Description

[Markus Stange [:mstange]]

Attachment: testcase

Scrolling in the middle part of this website is very slow: https://www.rocketbeans.tv/wochenplan/

This seems to be caused by the opacity on the "#schedule2017 .weekInner .day.blindfill" elements, which have fixed backgrounds.

The testcase shows the same slowness.

Comment 1

[Darkspirit]

Attachment: 2018-03-24_00-47-55.mp4

Debian Testing (KDE, Radeon RX480, 2560x1440)
main profile (Quantum Lights theme) and a fresh wr profile

Comment 2

[Darkspirit]

Attachment: 2018-04-30_19-05-22.mp4

Nightly 61 x64 20180430100522 de_DE @ Debian Testing (KDE, Radeon RX480)
main profile. (a fresh WR profile looks the same)

Current look. Mostly a square only shows up if I click on it.

Comment 3

[Darkspirit]

(In reply to Jan Andre Ikenmeyer [:darkspirit] from comment #2)
It's only broken if the height inside Nightly's KDE/gtk3 window is >= 1099px. The window width doesn't matter.

Comment 4

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

The WR side fix should be in the current WR update (i.e. the one on autoland). So presumably this will be fixed in the next nightly.

Comment 5

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

The WR issues have landed, do you still see this problem?

Comment 6

[Markus Stange [:mstange]]

It's fast now. This is fixed.