1684259 - Extreme slowness and overheating of the processor when resizing the window with many tabs due to long restyles.

Status: RESOLVED DUPLICATE of bug 1718337

(Core :: CSS Parsing and Computation, defect)

Description

[adasc]

Attachment: Gravação de tela de 26-12-2020 13:40:04.webm

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Firefox/78.0

Steps to reproduce:

I had several tabs accumulated and I only opened one at the beginning of the session. So I tried to adjust the size of the window and it was extremely slow, with a 20ºC increase in the processor temperature. It is the only animation that is extremely slow in Firefox, along with the animation of making a video fullscreen.

The problem also happens in other desktop environments, and there are more users reporting on the Firefox subreddit.

Actual results:

Extreme slowness and overheating of the processor when resizing the window with many tabs.

Expected results:

It should be fluid, without overheating the processor and not having very slow animation.

Comment 1

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

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.

Comment 2

[Emilio Cobos Álvarez [:emilio]]

(In reply to adasc from comment #0)

Created attachment 9194749 [details]
Gravação de tela de 26-12-2020 13:40:04.webm

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Firefox/78.0

Does this reproduce with a newer version of Firefox (like the latest release?)

Can you take a profile with https://profiler.firefox.com, with the preset set to "Firefox Platform" or "Firefox Graphics", then click "Share", and paste the link here please? Thanks.

Comment 3

[adasc]

https://share.firefox.dev/3aLFQpw

https://share.firefox.dev/3o3Wy7a

I don't know if I did it correctly, but that's it.

Comment 4

[Emilio Cobos Álvarez [:emilio]]

Thanks! Yeah, that looks useful, it seems we have massive restyles when changing the window size in some cases, which take ~half a second.

Comment 5

[Emilio Cobos Álvarez [:emilio]]

Do you know how many tabs did you have open on the second profile, so I can try to reproduce?

Comment 6

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

Clear a needinfo that is pending on an inactive user.

Inactive users most likely will not respond; if the missing information is essential and cannot be collected another way, the bug maybe should be closed as INCOMPLETE.

For more information, please visit auto_nag documentation.