1683802 - Slow/laggy scrolling on Glamour page

Status: RESOLVED FIXED

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

Description

[Asif Youssuff]

Basic information

Steps to Reproduce:

1. Load https://www.glamour.com/story/who-is-tayshia-adams
2. Scroll up and down.

Note: I am using software webrender.

Expected Results:

Smooth and responsive scrolling.

Actual Results:

Laggy and somewhat unresponsive scrolling.

---

More information

Profile URL: https://share.firefox.dev/3rkFRGU

Basic systems configuration:

OS version: Ubuntu 21.04

GPU model: Nvidia Quadro NVS 3100M

Number of cores: Intel(R) Core(TM) i5 CPU M 520 - 2 cores with hyperthreading

Amount of memory (RAM): 8GB

Thanks so much for your help.

Comment 1

[Asif Youssuff]

Attachment: about:support

Comment 2

[Markus Stange [:mstange]]

How much better is non-WebRender on this page?

Comment 3

[Alex Thayer [:alexical] (she/her)]

Resolving as incomplete for now, because software webrender seems to still outperform non-WebRender for me. If anyone has any more information as to why this should be performing better, please reopen.

Comment 4

[Alex Thayer [:alexical] (she/her)]

If you can configure Chrome with any similar-ish configuration (I don't know what would be apples to apples in Chrome compared with software WR), and see how that compares, that could also help prioritize this.

Comment 5

[Asif Youssuff]

Basic is slightly better as it doesn't visibly judder as I scroll. The page doesn't scroll perfectly in either case - in Basic, first scrolling the page seems to take a while for the portion after the first Twitter embed to appear. Once you scroll the page after that has popped in, it scrolls smoothly, whereas the sw-wr version has judder/micro-stutter beginning at that place (scrolling down past the first Twitter embed).

Here's a profile of Basic: https://share.firefox.dev/3iASsS5

Comment 6

[Alex Thayer [:alexical] (she/her)]

Markus, do I understand correctly that software WR is in some cases intended to replace hardware-accelerated non-WR stuff? Or is software WR generally replacing a software non-WR stack? I imagine there's some overlap, but what's the closest we can get to a fair comparison here / what is the graphics team's goal as far as performance parity goes?

I feel like in any case this seems like it should belong in the WebRender component though, so I'm moving it there.

Comment 7

[Markus Stange [:mstange]]

(In reply to Doug Thayer [:dthayer] (he/him) from comment #6)

Markus, do I understand correctly that software WR is in some cases intended to replace hardware-accelerated non-WR stuff?

Not that I'm aware, or at least not in the long run. In the short run it's possible that SWWR may be enabled on some devices that used to get D2D+D3D11 painting/compositing but which are still blocklisted for hardware WR, but those configurations are intended to eventually get hardware WR. In the long run, SWWR is only intended for those devices that did not have hardware acceleration in non-WR.

I imagine there's some overlap, but what's the closest we can get to a fair comparison here

The fairest comparisons are:
Old: D2D content + advanced layers / D3D11 compositing -> New: Hardware WebRender + DirectComposition
Old: Skia content + D3D11 compositing -> New: Software WebRender with RenderCompositorD3D11SWGL
Old: Skia content + BasicCompositor -> New: Software WebRender with RenderCompositorSWGL

what is the graphics team's goal as far as performance parity goes?

Not completely sure.

Comment 8

[Lee Salzman [:lsalzman]]

This mostly lives in image filtering fast-paths now.