1873620 - Scrolling a pdf janks and the scrolling itself pauses waiting for the pdf to draw on screen

Status: RESOLVED WORKSFORME

(Core :: Graphics: Canvas2D, defect)

Description

[Mayank Bansal]

Open attached pdf
Scroll using the touchpad specially pages 8-11 (also repros on later pages)

AR: the scrolling itself janks. Prior to the regressing bug, the page would checkerboard. Now, the scrolling is janky.

Profile of jank: https://share.firefox.dev/3RTAvjO
Extreme version(pdf zoomed to 400%) : https://share.firefox.dev/3tIgXqJ

Regressed by :
Bug 1871467 - Remove unnecessary CanvasTranslator locking. r=aosmond CLOSED TREE
Differential Revision: https://phabricator.services.mozilla.com/D197112

Skia-canvas and gpu-canvas work great.
This may be a dupe of bug 1872455

Comment 1

[Mayank Bansal]

Attachment: 2_Philp.pdf

Comment 2

[Mayank Bansal]

For reference, here is a profile from 01Oct2023 (pre regressing bug) : https://share.firefox.dev/48qDQOw

Comment 3

[Mayank Bansal]

Attachment: about:support

Comment 4

[BugBot [:suhaib / :marco/ :calixte]]

Set release status flags based on info from the regressing bug 1871467

:lsalzman, since you are the author of the regressor, bug 1871467, could you take a look? Also, could you set the severity field?

For more information, please visit BugBot documentation.

Comment 5

[BugBot [:suhaib / :marco/ :calixte]]

Set release status flags based on info from the regressing bug 1871467

Comment 6

[Mayank Bansal]

Latest profile : https://share.firefox.dev/4aYfmg9
Blocking in the compositor is gone, but there is still some jank while scrolling.

At this point, not sure if there is anything to fix from gfx side.

Comment 7

[Mayank Bansal]

Profile from latest Nightly: https://share.firefox.dev/4c0EmVg
The jank/hang while scrolling is still there.

Comment 8

[Mayank Bansal]

No longer janks.