1649313 - Add a profiler marker for canceled composites (if we bail out because there's nothing to do)

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, task)

Description

[Markus Stange [:mstange]]

Sometimes we expect 60 fps compositing but encounter frame skips, for example during video playback or during fling scroll animations. In some cases, these frame skips are not caused by slow compositing, but by "missing" compositing - when the "compositor state" at the time of composition indicates that nothing on the screen has changed.

Here's an example from 60 fps YouTube video playback: https://share.firefox.dev/2Zs6X1M
The compositor thread shows CompositeToTarget markers at a consistent 60fps, but the Renderer thread shows many gaps where it does not have Composite markers.

I think it's worth calling out compositor frames where there's "nothing to do" with a profiler marker.

Comment 1

[Markus Stange [:mstange]]

Attachment: Bug 1649313 - Add SkippedComposite markers. r=nical

Comment 2

[Markus Stange [:mstange]]

This patch doesn't call out frames where APZ didn't scroll. I think those don't get detected until we get into the Renderer thread.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/f737ced60117
Add SkippedComposite markers. r=nical

Comment 4

[Alexandru Michis [:malexandru]]

https://hg.mozilla.org/mozilla-central/rev/f737ced60117

Comment 5

[Alexandru Michis [:malexandru]]

https://hg.mozilla.org/mozilla-central/rev/f737ced60117