1975272 - Animated newtab background images consume CPU even when not in the foreground

Status: RESOLVED FIXED

(Firefox :: New Tab Page, defect)

Description

[Mike Conley (:mconley) (:⚙️)]

STR:

1. Download this GIF image: https://drive.google.com/file/d/1xvEHMjUX77D5wfEt3Ppjtb10iksP5Jxe/view?usp=sharing
2. In a new profile, set that image as the custom background
3. Open several new tabs
4. Visit about:processes, and look at the CPU usage of "About pages"

ER:

When newtab is backgrounded, we should try to avoid consuming any CPU except to prepare the next newtab opening.

AR:

It appears that the images that are animating are still causing the CPU to be consumed.

We might be able to easily solve this by setting the imageAnimationMode on the document to kDontAnimMode when in the background, and then set it to kNormalAnimMode when foregrounded.

Comment 1

[Mike Conley (:mconley) (:⚙️)]

Attachment: Bug 1975272 - Stop animations on newtab unless foregrounded. r?#home-newtab-reviewers!

Comment 2

[Mike Conley (:mconley) (:⚙️)]

This is fairly speculative, but certainly seems to drop the CPU usage way down when I have many tabs open.

This doesn't cover the preloaded newtab case, since that newtab thinks it is visible. If that is something we also want to solve, we may have reached the point where we accept the patch in bug 1548683, which makes the preloaded newtab not think it is visible.

Comment 3

[Timothy Nikkel (:tnikkel)]

Why is it that the refresh driver doesn't know that the document is background and so throttles the ticking?

Comment 4

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

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

For more information, please visit BugBot documentation.

Comment 5

[juraj.masiar]

See also bug 1972210

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/77a80c364554
https://hg.mozilla.org/integration/autoland/rev/c61112be68ae
Stop animations on newtab unless foregrounded. r=home-newtab-reviewers,nbarrett

Comment 7

[Cristina Horotan [:chorotan]]

https://hg.mozilla.org/mozilla-central/rev/c61112be68ae