1718242 - Firefox slows down when hovering addons icons

Status: NEW

(Core :: Graphics, defect, P3)

Description

[pierre.donias]

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:89.0) Gecko/20100101 Firefox/89.0

Steps to reproduce:

• Install a few addons
• Hover mouse over the addons icons at the top right-hand corner

Actual results:

Firefox slows down a lot the more you keep your mouse in that region and even freezes completely after a few seconds. After moving the mouse somewhere else, it takes a bit of time to unfreeze.

Expected results:

Hovering addons icons shouldn't have any impact on performance.

Comment 1

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

The Bugbug bot thinks this bug should belong to the 'Toolkit::Add-ons Manager' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Comment 2

[Alexandru Trif, Desktop QA [:atrif]]

Tried reproducing on Ubuntu 20.04 with 89.0, but with no luck. Installed a few random addons and hovered each one of them but the performance remained the same for me.

@pierre.donias can you please attach a list of addons you use to reproduce the issue? Also can you please open firefox with a new profile and see if the problem still occurs? Thank you in advance?

Comment 3

[Markus Stange [:mstange]]

If clicking the icon opens a panel, we prepare the panel contents during hover so that clicking reacts faster. However, it sounds like the performance impact from this optimization is much larger in this case than anticipated.

Pierre, could you also gather a performance profile? https://developer.mozilla.org/en-US/docs/Mozilla/Performance/Reporting_a_Performance_Problem

Comment 4

[pierre.donias]

Attachment: Performance profile 1

Comment 5

[pierre.donias]

@Alexandru, here's a list of all my addons:

• Adblock Plus - bloqueur de publicités gratuit
• AdBlocker Ultimate
• Alternate Player for Twitch.tv
• BetterTTV
• Bitwarden
• Clickbait Remover for Youtube
• CORS Everywhere
• Facebook Container
• I don't care about cookies
• I'm Feeling Lucky - Skip search
• Le Camelizer
• Modify Header Value (HTTP Headers)
• ng-inspect
• Pretty XML
• Privacy Badger
• React Developer Tools
• Refined GitHub
• SponsorBlock pour YouTube - Supprime les publicités intégrées
• Strava, export gpx track
• Stylus
• Tabby Cat
• Tampermonkey
• uBlock Origin
• Video Speed Controller
• YouTube Auto HD + FPS
• Dark Reader (disabled)

I created a new profile and only installed AdBlock Plus and I was able to reproduce the issue.

@Markus, I attached the performance profile to the ticket. Also, the panel render optimization might be a good lead because when I try to hover my mouse over an addon that doesn't have a panel, then it doesn't freeze (e.g.: with the "CORS Everywhere" addon).

Comment 6

[Markus Stange [:mstange]]

Interesting, thanks! The profile shows some very long composites.

Could you capture another profile with the "Firefox Platform" profiler preset?

Comment 7

[pierre.donias]

Attachment: Performance profile 2

Settings: Firefox platform

Comment 8

[pierre.donias]

@Markus, I attached it as "Performance profile 2".

Comment 9

[Nicolas Silva [:nical]]

Thanks for filing this. Could you you paste the content of the graphics section of your about:support page (type about:support in the url bar to get there)?

Comment 10

[pierre.donias]

Attachment: Graphics support

Comment 11

[pierre.donias]

It looks like I don't have this issue anymore (FF 95.0.1), has this been fixed?