1875210 - Performance regression on a codepen demo (https://codepen.io/zimjs/pen/xxjEyzG), extremely laggy browser UI and laggy Windows UI

Status: NEW

(Core :: Graphics: Canvas2D, defect)

Description

[Mayank Bansal]

Go to https://codepen.io/zimjs/pen/xxjEyzG

AR:
0. Demo barely rotates/animates

1. Some browser UI actions become extremely laggy. Example: Opening new tabs, profiling the demo etc. Recording profile and capturing it usually leads to complete hang of the UI.
2. The Windows UI becomes somewhat laggy
3. 95% "GPU copy" as shown by Windows Task Manager. From doing the bisection, high "GPU copy" is strongly correlated to the above 3 symptoms
4. The gpu use continues for 10s of seconds after you close the tab. Expectation would be that as soon as the offending tab is closed the processing should stop (and the UI responsiveness improves)

Good (1Oct2023) : https://share.firefox.dev/3Sx2xn3 (98% GPU 3d use, 0% gpu copy)
Bad(17Jan2024) : / https://share.firefox.dev/47ChcBr (70% GPU 3d use, 85% gpu copy)
Bad2 (somewhere between the above two revisions) : https://share.firefox.dev/490c6Qr

Regressed by :
Bug 1871467 - Remove unnecessary CanvasTranslator locking. r=aosmond CLOSED TREE

Differential Revision: https://phabricator.services.mozilla.com/D197112

Comment 1

[Mayank Bansal]

Attachment: about:support

Comment 2

[Mayank Bansal]

Attachment: bad gpu copy.png

Comment 3

[Mayank Bansal]

The reason this was so noticable was because the browser UI becomes laggy, which is a bad user experience. It feels as if the whole browser UI has locked up. Worse performance on the demo is still acceptable.

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?

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]

Slow browser UI is fixed by bug 1863257 and co.