1677825 - On Linux, losing WebRender falls back to OpenGL without the GPU process

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, defect, P2)

Description

[Andrew Osmond [:aosmond] (he/him)]

If WebRender fails to initialize gracefully, then we will hit this path:

https://searchfox.org/mozilla-central/rev/277ab3925eae21b419167a34624ec0ab518d0c94/gfx/ipc/GPUProcessManager.cpp#477

We disable WebRender via gfxVars, but we didn't disable HW_COMPOSITING like we do if we decide not to give the user WebRender:

https://searchfox.org/mozilla-central/rev/277ab3925eae21b419167a34624ec0ab518d0c94/gfx/config/gfxConfigManager.cpp#344

This means users are falling back to OpenGL if WebRender fails to init.

Comment 1

[Andrew Osmond [:aosmond] (he/him)]

Attachment: Bug 1677825 - Disable hardware acceleration if WebRender fails to initialize on Linux.

If we don't disable hardware acceleration when we lose WebRender, we
will likely fallback to OpenGL compositing. This is not a supported
configuration. We already do this step if we decide against using
WebRender during configuration, but not if it was lost at runtime.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/72e7d30ced00
Disable hardware acceleration if WebRender fails to initialize on Linux. r=jrmuizel

Comment 4

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

https://hg.mozilla.org/mozilla-central/rev/72e7d30ced00970f4d717f12ce3a01f5d202d1be

Comment 5

[Andrew Osmond [:aosmond] (he/him)]

Comment on attachment 9188404 [details]
Bug 1677825 - Disable hardware acceleration if WebRender fails to initialize on Linux.

Beta/Release Uplift Approval Request

• User impact if declined: Users may fallback to OpenGL compositing on Linux if errors occur with WebRender. We have never shipped the OpenGL compositor on Linux and it is many bugs.
• Is this code covered by automated tests?: No
• Has the fix been verified in Nightly?: Yes
• Needs manual test from QE?: No
• If yes, steps to reproduce:
• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): Trivial change, we just disable hardware compositing (#ifdef'd for Linux only) when we disable WebRender.
• String changes made/needed:

Comment 6

[Ryan VanderMeulen [:RyanVM]]

Comment on attachment 9188404 [details]
Bug 1677825 - Disable hardware acceleration if WebRender fails to initialize on Linux.

Approved for 84.0b3.

Comment 7

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-beta/rev/f090befbbfacda3136437f7ecc79d7ee395bf23c