1977046 - Canvas demo at https://js1k.com/2018-coins/demo/3197 has become very slow again

Status: NEW

(Core :: Graphics: Canvas2D, defect)

Description

[Mayank Bansal]

Go to https://js1k.com/2018-coins/demo/3197
Press Enter

Profile: https://share.firefox.dev/4lRgV5f

This demo was initially reported in bug 1800801 and much improved in bug 1789268

Comment 1

[Mayank Bansal]

Attachment: about:support

Comment 2

[Timothy Nikkel (:tnikkel)]

Is there a regression range for what caused it to be slow again?

Comment 3

[Mayank Bansal]

Not specifically, no. It got much better with Bug 1789268, but then became bad sometimes between then and now.
And very recently became worse with the accelerates-canvas-blur patches.

Comment 4

[Mayank Bansal]

Yeah, bisecting the more recent regression points to bug 1912897.

2025-07-13T07:59:42.149000: DEBUG : Found commit message:

Bug 1912897 - Support blurring and shadows for Accelerated Canvas2D. r=aosmond
Differential Revision: https://phabricator.services.mozilla.com/D255717

2025-07-13T07:59:42.150000: DEBUG : Did not find a branch, checking all integration branches
2025-07-13T07:59:42.152000: INFO : The bisection is done.

Comment 5

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

Set release status flags based on info from the regressing bug 1912897

:lsalzman, since you are the author of the regressor, bug 1912897, could you take a look? Also, could you set the severity field?

For more information, please visit BugBot documentation.

Comment 6

[Lee Salzman [:lsalzman]]

I am going to say this demo never actually ran acceptably fast in the first place, and on the scale of regressions, this is not that significant relative to how badly the demo performs. So it would be better to just address this from first principles rather than treat this as any sort of regression.