1453080 - Tab warming causes janky tab hover animations

Status: RESOLVED FIXED

(Firefox :: Tabbed Browser, defect, P3)

Description

[Brendan Dahl [:bdahl]]

With browser.tabs.remote.warmup.enabled set to true, my tab animations become very laggy/janky on MacOS. It seems to be most notable with pinned tabs.

STR:
- Pin several "heavy" sites (I have gmail, calendar, slack, ircloud)
- Move the mouse across these tabs a couple of times

The hover effect starts to fall behind where the mouse is actually located and I see the top border animation very slowly animate. My CPU usage from Firefox also shoots up to 100%.

Comment 1

[Mike Conley (:mconley) (:⚙️)]

Hey bdahl, do things improve if you set browser.tabs.remote.warmup.maxTabs to 1 (and then restart)?

Comment 2

[Brendan Dahl [:bdahl]]

It's better, but I still see the animation/hover fall behind occasionally.

Not sure if it's helpful, but here a profile with maxTabs at 3: https://perfht.ml/2qq7qRe

Comment 3

[Potch [:potch]]

In case they're useful, here's some profiles from my potato-grade 2016 12" MacBook:

Me scrubbing the tab bar with warming enabled: https://perfht.ml/2IszjlO
Me scrubbing the tab bar with warming disabled: https://perfht.ml/2IqQ29i

Comment 4

[Mike Conley (:mconley) (:⚙️)]

Hey bdahl, with bug 1265824 having been fixed, I suspect this has probably gotten better. It has for me, anyhow. Can you confirm?

Comment 5

[Brendan Dahl [:bdahl]]

Yeah, seems very smooth now!

Comment 6

[Mike Conley (:mconley) (:⚙️)]

\o/