1611582 - Scrolling on myheritage.com is very laggy with WebRender

Status: UNCONFIRMED

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

Description

[Václav Nováček]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:73.0) Gecko/20100101 Firefox/73.0

Steps to reproduce:

1. Go to https://www.myheritage.com/site-family-tree-144530322/demo-family-site
2. Scroll to the area with many people displayed (e.g. Rose Kennedy *1890 on the right)
3. Drag the page and circle with mouse.

Actual results:

Scrolling is very laggy on my AMD Ryzen 5 2600 and Nvidia GTX 1060 3GB. Firefox process consumes about 15% of cpu power and up to 20% of gpu power when WebRender is enabled. When WebRender is off it's much better, cpu takes about 10% and no gpu.

Test config:
Windows 10 1909 18363.592
Firefox 73b9, 71a1

Expected results:

Scrolling should be much better when WebRender is on.
Chrome takes about 1% of cpu power and zero gpu power.

Comment 1

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

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.

Comment 2

[Jeff Muizelaar [:jrmuizel]]

This seems to run okish on MacOS on Nightly. Václav are you able to check if things are any different on Nightly? Also what screen resolution are you running at?

Comment 3

[Václav Nováček]

A have tested it on nightly 74a1 (not 71a1 as I wrote) as well with the same result.
I run at 4k (3840x2160) screen resolution.

Comment 4

[Václav Nováček]

I was wrong with the Chrome gpu results, gpu load is also up to 20%, however it's absolutly smooth with 1% cpu. I will try to do some regression tests tomorrow. According observation it's worse when more elements is displayed, e.g. when you zoom in and icons appear next to full birth and death date.

Comment 5

[Jeff Muizelaar [:jrmuizel]]

Can you try turning on gfx.webrender.blob.paint-flashing and report roughly how much of the screen is flashing when it's slow?

Comment 6

[Václav Nováček]

I have tested the paint-flashing flag, see results in the youtube video https://youtu.be/X7OP1HdZB40.
Edges of the page are flashing with every move, content in the middle flashes as well, but not so often.

Comment 7

[Václav Nováček]

Added another video with more fps... https://youtu.be/sBg6cl907Sc. This demo familly tree is quite small, so the lags do not look so terrible, at familly tree with hunderts of people it's more visible.

Comment 8

[Václav Nováček]

I have done mozregression test. The old Direct3D compositor (last from 2018-10-22) has much better results, there are repainted only edges, not the whole content.

Comment 9

[Jeff Muizelaar [:jrmuizel]]

Václav, can you gather a profile using profiler.firefox.com?

Comment 10

[Václav Nováček]

There is it... https://perfht.ml/398s784

Comment 11

[Jeff Muizelaar [:jrmuizel]]

Can you add the following "Renderer,RenderBackend,WrWorker" to "Add custom threads by name:" in the profiler settings dialog and get a new profile?

Comment 12

[Václav Nováček]

Sure, there you go... https://perfht.ml/3bgjH0y

Comment 13

[Jeff Muizelaar [:jrmuizel]]

That profile was great. Thanks a lot. It looks like there's something very fishy going on. I've filed bug 1613402 to investigate that particular problem.

Comment 14

[Václav Nováček]

I have tested build a8e8db10bcc4 which supposed to comprise fixed bug 1613402. It's better now, but still not fluent. I think blobs are repainted too often and unnecessarily.
A new profile here... https://perfht.ml/2H12MRA

Comment 15

[Jeff Muizelaar [:jrmuizel]]

(In reply to Václav Nováček from comment #14)

I have tested build a8e8db10bcc4 which supposed to comprise fixed bug 1613402. It's better now, but still not fluent. I think blobs are repainted too often and unnecessarily.
A new profile here... https://perfht.ml/2H12MRA

That profile doesn't have symbols. Can you try again when that fix makes it into Nightly?

Comment 16

[Václav Nováček]

Ahh, right. I'll try to profile it tomorrow again.

Comment 17

[Václav Nováček]

Here we go... https://perfht.ml/2OAoos3

Comment 18

[Jeff Muizelaar [:jrmuizel]]

We're doing a lot of texture upload. Don't understand yet why.