1581299 - Phantom render error. Hard to reproduce.

Status: RESOLVED INACTIVE

(Core :: Graphics: WebRender, defect, P3)

Description

[juhyt80]

Attachment: Bug

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:70.0) Gecko/20100101 Firefox/70.0

Actual results:

Sometimes Firefox renderer goes wild before some page update happens. I believe it goes from Firefox 60' update. Finlay I catch it during dev! So here is a proof.
It always wired things like black rect, color changing, ...
I think, that caused by some errors in renderer engine.
Usually I find this on GitHub, but it can happens on any site.

Comment 1

[Jamie Nicol [:jnicol]]

Hi, thanks for the report. Which GPU does your computer have, and are your drivers up to date? Are you able to attach your about:support to this bug? Is there any specific behaviour which causes this to happen? And does it go away eventually or do you need to restart the browser to fix it?

Comment 2

[Jamie Nicol [:jnicol]]

This seems pretty bad but setting as P3 for now until we establish quite how hard to reproduce and how widespread it is.

Looks like it could be texture cache corruption, or reading from the wrong location in the texture cache. Have you seen anything like this or can you think of any reasons why that might be happening, Dzmitry?

Comment 3

[juhyt80]

I am using gtx 1050 with the latest drivers on this pc. I will try to give more information a bit later. This bug goes immediately after any page update happens (like css hovering ). I don't know what can cause this. Maybe media content on other tabs.

Comment 4

[juhyt80]

Attachment: Raw data

Comment 5

[juhyt80]

My about:support raw data.

Comment 6

[Dzmitry Malyshau [:kvark]]

The closest thing that comes to mind is our GPU cache corruption on NV driver wake-up from sleep on Linux. But this issue seem to be unrelated: if it happens on CSS changes, it's just the scene builds that cause the corruption of either the GPU cache or the texture cache. It would be best if we could get a WR capture that shows the issue.

On Windows, to get a WR capture:

1. When you see the issue, hit "CTRL + SHIFT + 3". You'll notice a second-ish pause - the browser reads the state and serializes it to disk.
2. The wr-capture folder would appear in "C:\Users\<username>\AppData\Local\Nightly\wr-capture` folder (for Firefox Nightly). Please zip it and share, e.g. via Firefox Send.

Comment 7

[juhyt80]

Okay, I will do it the next time.

Comment 8

[juhyt80]

Attachment: currupted.bmp

Corrupted render

Comment 9

[juhyt80]

I just have captured new screenshot and it seems like there is more than page corruption.

Comment 10

[juhyt80]

Attachment: should_be.bmp

To compare.