Closed Bug 1677883 Opened 5 years ago Closed 5 years ago

Navigation lag in text boxes with scrollbars when webrender & layers.acceleration are enabled

Categories

(Core :: Graphics: WebRender, defect)

Product:
Core
Component:
Graphics: WebRender
Version:
Firefox 82
Type:
defect

Tracking

()

Status:
RESOLVED DUPLICATE of bug 1675414

People

(Reporter: daboross, Unassigned)

Details

User Agent: Mozilla/5.0 (X11; Fedora; Linux x86_64; rv:82.0) Gecko/20100101 Firefox/82.0

Steps to reproduce:

To reproduce:

  • Create a new Firefox profile
  • In about:config, set the following options:
    • gfx.webrender.all true
    • gfx.webrender.enabled true
    • layers.acceleration.force-enabled true
  • Get some input with many, many lines. On linux, this could be running "yes a | head -n 100", and copying the output. Might reproduce with as few as 5 or 6 lines, but it's easier to reproduce with more.
  • Open a website with a textbox, such as a bugzilla bug - like https://bugzilla.mozilla.org/show_bug.cgi?id=1584050.
  • Paste the 100 lines of "a" into the textbox.
  • Importantly, ensure the textbox has a scrollbar showing. If you expand the textbox to hold all the input on the screen, then it doesn't reproduce.
  • Try to navigate, either using left arrow key, right arrow key, or ctrl-left and ctrl-right arrow keys.

I'm running Firefox 82.0.3 on Fedora 33. I'm running in wayland mode (MOZ_ENABLE_WAYLAND environmental variable set to 1) inside the Sway window manager / display environment.

Disabling layers.acceleration.force-enabled fixes this, as does disabling webrender. I'd like to keep both enabled for other reasons, though - and it does seem to be a bug!

I've got a bunch of config options changed, but I can reproduce it
I have the following config options enabled:

  • gfx.webrender.all true
  • gfx.webrender.enabled true
  • layers.acceleration.force-enabled true

Since the bug depends on my enabling webrender, I've submitted it under that component. If there is a more appropriate place to put this, please recategorize! Thanks.

Actual results:

When using arrow keys to navigate, the cursor only updates every 1-2 seconds. Instead of being instant, like when typing (or navigating in a text box with fewer lines), it takes a noticably long time for the cursor to update. When it does update, it updates all at once (so every 1-2 seconds, the screen is updated with the real cursor - it's not like all movement is delayed by 1-2 seconds, but more like the position displayed isn't updated except every 1-2 seconds).

Expected results:

Navigation should instantly update the cursor in all cases.

Duplication of Bug 1675414?

Status: UNCONFIRMED → RESOLVED
Closed: 5 years ago
Resolution: --- → DUPLICATE
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