Open Bug 1625433 Opened 4 years ago Updated 2 years ago

Text and background elements animations are stuttering on fantasy.bnf.fr

Categories

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

Desktop
Windows 10
defect

Tracking

()

Tracking Status
firefox74 --- disabled
firefox75 --- affected
firefox76 --- affected

People

(Reporter: daniel.kolsis, Unassigned)

References

(Blocks 1 open bug)

Details

(Keywords: perf)

Attachments

(1 file)

Affected versions:
Nightly 76.0a1 (2020-03-27) and Beta 75.0b9

Affected platforms:
Platforms: Windows

Steps to reproduce:

  1. Reach about:support and verify that Compositing shows Webrender
  2. Reach https://fantasy.bnf.fr/

Expected result:
When the page loads the text and background animations are smooth without lag or stutter.

Actual result:
The Text and background animations are lagging and jiggle.
Please note that with gfx.webrender.force-disabled = true the animations are better but still not as smooth as they are on Chrome.

This issue occurs on Windows 10 with Intel GPUs as well as Nvidia and AMD Radeon RX 5700 XT.

OS: Unspecified → Windows
Hardware: Unspecified → Desktop
Version: unspecified → Trunk
OS: Windows → Windows 10

Hi! Thanks for the report. When I have webrender disabled it still lags, but the text no longer jiggles around. With webrender enabled it both lags and jiggles. Does that match your experience?

Andrew, could the text jiggling be a snapping issue?

Most of the time in webrender is spent in swapbuffers. Which matches what the profiler says, with GPU time dominating (~15ms). Any ideas Glenn or Nical?

Blocks: wr-perf
Flags: needinfo?(nical.bugzilla)
Flags: needinfo?(gwatson)
Flags: needinfo?(aosmond)
Keywords: perf
Priority: -- → P3

On windows with an nvidia GPU I'm The CPU side of things looks reasonable, the only thing standing out being RendererOGL::WaitForGPU (75% of the renderer thread). So we are waiting on the GPU. Will have to look into it with renderdoc to see what's going on.

On Linux (and any configuration where we don't have device texture sharing), it's a bit of a horror show. The content main thread spending a long time reading back the canvases and the renderer uploading it back to the GPU.

Nical, did anything seem to stand out in the GPU profile? It seems a bit odd that we'd be hitting GPU waits on high end discrete GPUs on Windows, unless something unexpected is going on.

Flags: needinfo?(gwatson)

I had a look in renderdoc and we have two full-screen images (canvases) in the alpha pass. I don't remember why I said I was running on the nvidia GPU. It could be that this was running on the intel one I'll check again.

Because this bug's Severity has not been changed from the default since it was filed, and it's Priority is P3 (Backlog,) indicating it has been triaged, the bug's Severity is being updated to S3 (normal.)

Severity: normal → S3
Flags: needinfo?(nical.bugzilla)
Flags: needinfo?(aosmond)
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