1438958 - Occasional rendering glitches that affect chrome and content with Web Render

Status: RESOLVED INACTIVE

(Core :: Graphics: WebRender, defect, P2)

Description

[Tobias (:Tobbi) Markus]

This is likely gonna be very vague.

Currently, my Firefox looks like this:
http://prntscr.com/ifq1g2

I have webrender and webrendest enabled. I can't tell whether they have anything to do with this. Since it's an occasional thing, I don't really have any steps to reproduce.

You can find my about:support content here:
https://pastebin.com/Vi3FweUf

Comment 1

[Dzmitry Malyshau [:kvark]]

Could be related to https://github.com/servo/servo/issues/20239

Comment 2

[Dzmitry Malyshau [:kvark]]

Tobias, do you still see this issue? Would be great to get a WR capture (folder "wr-capture" appears in the working folder of Nightly executable once you hit Ctrl+Shift+3).

Comment 3

[Tobias (:Tobbi) Markus]

(In reply to Dzmitry Malyshau [:kvark] from comment #2)
> Tobias, do you still see this issue? Would be great to get a WR capture
> (folder "wr-capture" appears in the working folder of Nightly executable
> once you hit Ctrl+Shift+3).

Since it happens so infrequently, I cannot be sure at this point. But I'll keep an eye on it and do what you told me when I see it.

Comment 4

[Tobias (:Tobbi) Markus]

I just got this issue again. However, pressing the above shortcut doesn't seem to do anything. I tried searching for a capture_webrender directory on my Mac, but it didn't find any.

Any ideas? For now I'll keep my Nightly like this.

Comment 5

[Dzmitry Malyshau [:kvark]]

The way it currently works is that Firefox tries to create "wr-capture" folder in the working directory. If on Mac you launched Firefox from the menu, the working folder would not have permissions to create a folder. Please try launching it from terminal and then checking for this folder.

Comment 6

[Tobias (:Tobbi) Markus]

I was able to capture a wr-capture at the time of the bug. You can get it from http://tobbi.bplaced.net/krams/wr-capture.zip

Comment 7

[Tobias (:Tobbi) Markus]

Another one (for maybe cross-referencing or something):
http://tobbi.bplaced.net/krams/wr-capture_2.zip

Comment 8

[Dzmitry Malyshau [:kvark]]

Thanks Tobias, I'm able to see the corruption on my side thanks to your captures. No idea why this happens, yet.

Comment 9

[Dzmitry Malyshau [:kvark]]

So far, it looks like a general failure of WR to keep its internal state consistent. Some texture arena or a freelist has gone wild, and we end up with a broken frame. It would be great to have some sort of validation logic in place that we'd use for captures received from the users.

Comment 10

[Dzmitry Malyshau [:kvark]]

Attachment: investigation.txt

Uploading the first WR capture investigation notes. The image item, entry, texture entry, and GPU block for UV coordinates all look good. I can think of two ways the logic can go wrong in this case:
  1. since this is a blob image, the contents might have been obtained by the wrong source? i.e. the blob image handler/rasterizer provided by Gecko had internal failure
  2. texture atlas allocation got wrong, and there is another element placed on the same texels. We need a validation routine to detect this.

Comment 11

[Jeff Muizelaar [:jrmuizel]]

Tobias can you still reproduce this?

Comment 12

[Tobias (:Tobbi) Markus]

(In reply to Jeff Muizelaar [:jrmuizel] from comment #11)
> Tobias can you still reproduce this?

I cannot be certain since this happens once every few months at most. I haven't had this issue in a few months now, but that doesn't mean it's stopped occuring alltogether.

Comment 13

[Tobias (:Tobbi) Markus]

(In reply to Jeff Muizelaar [:jrmuizel] from comment #11)
> Tobias can you still reproduce this?

I can still reproduce this. Just had the same issue again!

Comment 14

[Jeff Muizelaar [:jrmuizel]]

You're only seeing this on Mac right?

Comment 15

[Tobias (:Tobbi) Markus]

(In reply to Jeff Muizelaar [:jrmuizel] from comment #14)
> You're only seeing this on Mac right?

Yes.

Comment 16

[Jessie [:jbonisteel] pls NI]

Curious if you still see this issue?

Comment 17

[Tobias (:Tobbi) Markus]

Since I've just re-enabled WebRender on my machine, I can't tell for sure that it's fixed because it only happens sporadically...So I guess the best course of action would be to wait a few months and see whether it resurfaces.

Comment 18

[Tobias (:Tobbi) Markus]

I haven't had this problem in a few years, but my old machine isn't used anymore. So, I guess INACTIVE is warranted.