1563859 - Consider enabling WebRender for Mesa/Nouveau

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, task)

Description

[Darkspirit]

Attachment: aboutsupport.txt

Ubuntu 19.04, GTX1060, Mesa/Nouveau, 2560x1440

WebRender is already enabled for AMD and Intel with Mesa 18 and greater.
It would be nice if Mesa/Nouveau could be declared as qualified as well.

• Using multiple windows while watching https://www.youtube.com/watch?v=7OrLroFa0AI in 4K works smoothly.
• https://testdrive-archive.azurewebsites.net/performance/chalkboard/
  Basic: 104.39 seconds
  WebRender: 10.00 seconds
• One visible difference: On the first second after Nightly startup, window content is black with Basic, but transparent with WebRender. I perceive transparent as more pleasant.

Comment 1

[Darkspirit]

Attachment: glxinfo.txt

Comment 2

[Jeff Muizelaar [:jrmuizel]]

Sounds reasonable.

Comment 3

[Darkspirit]

Some Nouveau background to provide some certainty:

• Chromium once blacklisted Nouveau because of an UI bug that could appear after surfing for a while. They don't care about improving their blacklist by themselves, but would accept patches.
  https://bugs.chromium.org/p/chromium/issues/detail?id=876523#c34
  Bug was fixed upstream with Mesa 18.2.0: "100177 - [GM206] Misrendering in XCOM Ennemy Within"
  Thus Mesa 18.2.0 could be defined as base line, or just Ubuntu 19.04 (Mesa 19.0.2).
• GTX1060: There is a "secure boot"-related(?) bug causing a fallback to mesa/llvmpipe on cold boot. (secboot: error during falcon reset)
  Functioning workaround: "in my case the firmware always fails to load unless I reboot from Windows or immediately after removing the Nvidia blob."
  https://bugzilla.redhat.com/show_bug.cgi?id=1508088
  https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1822987
  https://bugs.freedesktop.org/show_bug.cgi?id=103946
  https://bugzilla.kernel.org/show_bug.cgi?id=200939
• Pascal: There is no proper power management at the moment: GPU fan is always at maximum. Devices might be in low performance mode by default. I didn't notice anything negatively regarding WebRender (comment 0). https://www.phoronix.com/scan.php?page=news_item&px=Nouveau-XDC2017
• In contrast to the inconvenient proprietary Nvidia experience (bug 1560457) there doesn't seem to be tearing by default with Nouveau.
• News archive: https://www.phoronix.com/scan.php?page=news_topic&q=Nouveau

Wayland:

• If using mesa/llvmpipe due to above bug, Gnome and KDE themselves are unusable slow. It takes seconds for keyboard input to appear on the screen.
• mesa/nouveau: Great. (comment 0)

X11:

• If using mesa/llvmpipe due to above bug, Gnome and KDE are usable with tolerable performance. To be able to use WebGL at all based on llvmpipe is better than no WebGL. But scrolling was smoother with Skia than with WebRender.
• mesa/nouveau: Great. (comment 0) Already VAAPI/VDPAU support for some old devices.

mesa/llvmpipe doesn't have Nvidia's vendor ID on X11 and Wayland, it would anyway not be qualified:

"windowLayerManagerType": "WebRender",
"windowLayerManagerRemote": true,
"windowUsingAdvancedLayers": false,
"adapterDescription": "llvmpipe (LLVM 7.0, 256 bits)",
"adapterVendorID": "0xffff",
"adapterDeviceID": "0xffff",
"adapterRAM": "7914MB",
"adapterDrivers": "",
"driverVendor": "mesa/llvmpipe",
"driverVersion": "18.3.6.0",
"driverDate": "",

Comment 4

[Darkspirit]

Have a (tested) patch for this. Waiting for bug 1563854 to land first.

Comment 5

[Darkspirit]

Attachment: Bug 1563859 - Enable WebRender on Linux with Nvidia hardware and Mesa drivers. r?jrmuizel

Comment 6

[Darkspirit]

Copied from AMD:

• https://searchfox.org/mozilla-central/rev/883bfd385efc917d5e787ba66fb51824f6f0e3d6/gfx/thebes/gfxPlatform.cpp#2666-2677
• Commit message: bug 1554251

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/1f4a148d28f8
Enable WebRender on Linux with Nvidia hardware and Mesa drivers. r=jrmuizel

Comment 8

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/1f4a148d28f8