1956931 - High CPU usage after clicking buttons on at least one site

Status: UNCONFIRMED

(Core :: Performance: Responsiveness, defect)

Description

[Filo]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:136.0) Gecko/20100101 Firefox/136.0

Steps to reproduce:

Visit https://www.jumbo.com
Click on ANY button on the site but for reference I used the Shopping Cart button on the top right, and the button next to it, but for that one to work you need to login.

Actual results:

The CPU usage jumps from 1%~ in Task Manager to 15-20% on i9-13900k
The CPU usage in about:processes jumps from 1% to 90-110% for a second after clicking the button.

This tanks the performance on the site, repeated clicks on different buttons makes the site insufferable to navigate on.

Profiler (clicked 1 second after):
https://profiler.firefox.com/from-browser/calltree/?globalTrackOrder=0&hiddenLocalTracksByPid=19208-1wrtwx0&implementation=js&thread=0&v=10

I'm not entirely sure when the issues start occuring as I only use this site once a week, but it did start happening with 136.0.3 or 136.0.4

Expected results:

Firefox and my computer should have zero problems navigating this site without noticeable performance issues.

Comment 1

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

The Bugbug bot thinks this bug should belong to the 'Firefox::Messaging System' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[Dennis Schubert [:denschub]]

Filo, when capturing a profile, you have to click the "upload local profile" button and then share the URL this panel shows us. The link you posted in comment 0 doesn't work for us because you didn't upload it.

Can you please capture another profile and submit that URL?

Comment 3

[Filo]

(In reply to Dennis Schubert [:denschub] from comment #2)

Filo, when capturing a profile, you have to click the "upload local profile" button and then share the URL this panel shows us. The link you posted in comment 0 doesn't work for us because you didn't upload it.

Can you please capture another profile and submit that URL?

Oops, I did another one here while clicking buttons and mousing over elements:
https://share.firefox.dev/3FTtlKf

Seems to be triggering while mousing over elements as well.

This is in Firefox 137.0

Comment 4

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

The severity field is not set for this bug.
:bas.schouten, could you have a look please?

For more information, please visit BugBot documentation.

Comment 5

[Bas Schouten (:bas.schouten)]

I tried to reproduce this, but couldn't. In the posted profile it appears uBlock Origin is triggering a lot of work, could you see if the issue still occurs when uBlock Origin is disabled?