1782216 - With Fission enabled, codepen demo flickers/glitches when pinch-zoomed

Status: NEW

(Core :: Graphics: WebRender, defect)

Description

[Mayank Bansal]

Use latest nightly. Make sure Fission is enabled.
Go to https://codepen.io/amit_sheen/pen/NWgJLKd
Configure the page such that the demo is on the left pane, and the editor is on the right pane
Pinch-zoom slowly

AR: Glitches at the edge of the screen
ER: Not so

Regression gave me the following :

Bug 1732358 - Part 5: Add the fission rollout slug to the GRADUATION_SET, r=mythmon
Depends on D133008
Differential Revision: https://phabricator.services.mozilla.com/D133659

With Fission disabled, a build from Jul-21 doesnt repro the bug. But when I manually enabled fission, I could repro.
Therefore, this bug is triggered by fission (but may have root cause elsewhere)

Comment 1

[Mayank Bansal]

Attachment: Bug.mp4

Comment 2

[Mayank Bansal]

Attachment: about:support of a build from Jul-21 with fission manually enabled

Comment 3

[Mayank Bansal]

If you export the demo to your local machine and run the demo from there, the bug doesnt repro.
Tentatively marking bug 1732358 as the regressor.

Comment 4

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

Set release status flags based on info from the regressing bug 1732358

Comment 5

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

:nika, since you are the author of the regressor, bug 1732358, could you take a look?
For more information, please visit auto_nag documentation.

Comment 6

[Nika Layzell [:nika] (ni? for response)]

Redirecting ni? to :emilio who is more familiar with the setup we use for pinch-zoom with Fission.

Comment 7

[Emilio Cobos Álvarez (:emilio)]

This is probably an APZ and/or WebRender bug, more than fission per se. Probably WR is clipping / culling primitives a bit too aggressively or so?

Comment 8

[Mayank Bansal]

With my daily profile, the demo causes Nightly to turn white, but no crash report is generated. The following message is printed in log :

2022-07-30T09:42:19.423000: INFO : platform_repository: https://hg.mozilla.org/mozilla-central
2022-07-30T09:42:19.423000: INFO : platform_version: 105.0a1
2022-07-30T09:42:35.061000: INFO : b'[GFX1-]: DCompositionSurface::BeginDraw failed: 0x80070057 Rect(x=526336, y=525312, w=0, h=0)'
2022-07-30T09:42:35.062000: INFO : b'[GFX1-]: Handling webrender error 4'
2022-07-30T09:42:35.062000: INFO : b'[GFX1-]: Fallback WR to SW-WR + D3D11'

(this might be the same as bug 1750348)

Comment 9

[Glenn Watson [:gw]]

Un-assigning for now since it's not a recent regression, but we'll need to fix this one in WR - from comment 8 it appears to be an issue with how we use DC.