795474 - Pauses in CSS transition demo

Status: RESOLVED WORKSFORME

(Core :: Graphics, defect)

Description

[Marco Castelluccio [:marco]]

There are many pauses during the animation on this page.

Comment 1

[Marco Castelluccio [:marco]]

I can still reproduce.

Comment 2

[Markus Stange [:mstange]]

The Performance Priority Calculator has determined this bug's performance priority to be P3.

Platforms: [x] macOS [x] Linux
[x] Affects animation smoothness
[x] Able to reproduce locally

Comment 3

[Markus Stange [:mstange]]

Locally I see some skipped frames, but it's mostly fine: https://share.firefox.dev/3uePdH3

Do you see longer pauses? Could you capture a profile on your machine? https://profiler.firefox.com/

Comment 4

[Markus Stange [:mstange]]

Needinfo'ing myself because I am surprised that we are skipping frames on the main thread due to late composites.

Comment 5

[Marco Castelluccio [:marco]]

https://share.firefox.dev/3OyD6Ng

Comment 6

[Markus Stange [:mstange]]

Interesting. There's one 130ms pause where vsync simply stops firing: https://share.firefox.dev/3ApY7Wp
Not sure what's up with that.

Comment 7

[Markus Stange [:mstange]]

It was probably due to some other activity on the IPDL background thread. If this still happens, please reopen and capture a profile with ",background" added to the thread filter, and the IPC profiling feature turned on.