Making a metabug to keep track of the UI glitches we are getting reports about. These glitches are very hard to reproduce and we don't have STR yet, but I want to keep track of them to try and find common themes

Potentially significant - the screenshots in https://bugzilla.mozilla.org/show_bug.cgi?id=1600357 and https://bugzilla.mozilla.org/show_bug.cgi?id=1603913 both have a sidebar-style view open. I wonder if that makes the glitch more likely to happen?

Another theory:

We have this existing crash bug [1]. Looking at the crash data, it spiked in volume in October, and then dropped off significantly. I think the bug fix in [2] may have helped this.

Nonetheless, there are still a small volume of crashes we're seeing (typically 0-2 / day).

Why is this interesting? The code that is crashing does an unwrap on a piece of data (the clip task address) that it's expecting should definitely be valid at that point. The only way this crash can occur is if some very unexpected condition has occurred during primitive preparation / batching (for example, a stale index into a previous frame's primitive data).

It seems plausible that since this is happening, the root cause of the bug might also not cause a crash in some cases, but result in an invalid primitive being drawn, which might show up exactly as the kinds of glitches we are seeing in this meta bug.

If we're able to get a URL for the bug in [1], we might be able to reproduce locally and see if it could also be causing the ui glitches...

[1] https://bugzilla.mozilla.org/show_bug.cgi?id=1582029
[2] https://bugzilla.mozilla.org/show_bug.cgi?id=1592121

Hi QA,

We have been tracking these UI glitching bugs (see bugs blocked against this meta bug) for awhile now and we need to determine clear STR. I know ya’ll have already been testing WebRender for awhile now and haven’t reported these issues, but we are wondering if we can get some focused help to try and track these down. So far, reporters are saying these bugs happen randomly. Here are a couple of examples of the bug occurring:

https://bugzilla.mozilla.org/show_bug.cgi?id=1598081#c0
https://bugzilla.mozilla.org/show_bug.cgi?id=1600357#c0
https://bugzilla.mozilla.org/show_bug.cgi?id=1609031#c0

It is likely you’ll have to be using WR continuously (8hrs+) to try and reproduce this. It is also worth trying with a dual monitor set up and trying for another long period of time just scrolling through various websites to see if this happens. The majority of reports so far come from people using Nvidia Graphics cards, so we’d recommend trying with one of those (for example: NVIDIA GeForce RTX 2060, NVIDIA GeForce GTX 1060).

Hi, I tried to reproduce these issues on a Dell Laptop with NVIDIA GeForce GTX 1050 and a second monitor attached to it but without success, I tested various websites like 9gag, pinterest, sketchfab, twitch, netflix, youtube but mostly Reddit.

Scrolling, resizing windows, Zooming in and out for a few hours changing custom themes or using the Dark Reader add-on did not help me reproduce these issues.
I also left the Laptop on overnight with a lot of tabs open and a few games started in separate tabs and windows like https://www.kongregate.com/games/kodiqi/idle-breakout or Facebook Farmville but no glitches or issues occurred.

We also tested this issue with just the Laptop's display no external monitor attached and using the same websites and stress factors but we couldnt reproduce those glitches on our end.

Chances are those issues are caused by more than just one factor like WebRender, and maybe even with the same exact GPU's we still wouldnt be able to reproduce the issue. Maybe the users plug in and out their external monitors more often, or maybe they are using docking stations which might make their gpu's go haywire.

Please let me know if there is anything more we can do. In the meantime we will keep an eye out for these types of glitches.

I suspect that https://bugzilla.mozilla.org/show_bug.cgi?id=1617083 will fix the majority of the UI glitches that are part of this metabug.

There are at least a few linked bugs here that are somewhat different, but I think it will fix the majority of them.

I'll leave this bug open once that lands, as we'll need to do a fair amount of testing before we're sure it has fixed the problem.

Hello I'm a browser/graphics engineer from NVIDIA. Do Mozilla keep a list of searchable browser graphics bugs occurring on NVIDIA platform? We might be able to help out on some of these.