1598789 - Terrible scrolling performance in portions of taskcluster log

Status: RESOLVED INCOMPLETE

(Core :: Graphics: WebRender, defect, P3)

Description

[Josh Matthews [:jdm]]

Scrolling performance on this taskcluster log is fine until you start scrolling near the bottom of the page where log lines start extending out of the viewport horizontally. Once those lines are back out of the viewport, the scrolling is fluid as expected. The profile I captured (https://profiler.firefox.com/public/772a0bd5bdc813884e6a9d97dee0d92941ef873e/calltree/?globalTrackOrder=0-1-2-3-4-5-6-7-8-9&hiddenGlobalTracks=1-2-3-4-5-6-7-8&localTrackOrderByPid=54790-22-23-0-1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18-19-20-21~54793-0~54791-0~62892-0~11816-0~93019-0~10376-0~85119-0~67500-0~85345-0~&thread=31&v=4) shows 70% of time in the Renderer thread is spent under Gl::buffer_data_untyped, with 19% of time spent waiting for the GPU to finish with the previous frame.

Comment 1

[Emilio Cobos Álvarez (:emilio)]

Curious if this is a regression...

Comment 2

[Emilio Cobos Álvarez (:emilio)]

I can see this on Linux too, for what is worth.

Comment 3

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

The priority flag is not set for this bug.
:jbonisteel, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 4

[Glenn Watson [:gw]]

Referenced page no longer exists.