1693400 - [Multi GPU] Firefox 86 DE has regular huge FPS drops on Linux (at least Wayland & Xwayland on KWin)

Status: RESOLVED WORKSFORME

(Core :: Widget: Gtk, defect, P3)

Description

[Erin of Yukis [:ntninja]]

Attachment: profile.json (Wayland)

Since about Firefox 86.0b2, the browser has become very hard to use due to regular huge FPS drops in rendering. Firefox 85 on Wayland is not affected by this and shows no stuttering in the main window. Firefox 86.0b9 on Xwayland (MOZ_ENABLE_WAYLAND=0) doesn't (subjectively) stutter as noticeably, but its still there and in both cases the stuttering shows up in the Browser Toolbox's runtime analyzer – trace attached. Opening windows (menu popups, the toolbox) takes several seconds in many cases.

On startup the following text is printed on stdout/stderr:

[GFX1-]: More than 1 GPU from same vendor detected via PCI, cannot deduce device

###!!! [Child][RunMessage] Error: Channel closing: too late to send/recv, messages will be lost

[GFX1-]: More than 1 GPU from same vendor detected via PCI, cannot deduce device

Host configuration:

• Debian unstable amd64
• Linux 5.10.0-2 x86_64 (Debian versioning)
• KWin 5.20.5
• Xwayland 1.20.10
• libdrm 2.4.104
• mesa 20.3.4
• GPU1: AMD Carrizo GCN 1.2 using amdgpu kernel driver and Mesa userland
• GPU2: AMD Radeon R9 M290X GCN 1.0 using amdgpu kernel driver and Mesa userland

Comment 1

[BugBot [:suhaib / :marco]]

The Bugbug bot thinks this bug should belong to the 'Core::Widget: Gtk' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Comment 2

[Martin Stránský [:stransky] (ni? me)]

I think I see similar issue on my box, it may be caused by Wayland multi GPU architecture when all rendering is done on one card only and the buffers are shared by dmabuf across the cards.

Comment 3

[Martin Stránský [:stransky] (ni? me)]

This should be already fixed, we read GL config from OpenGL right now and enable WebRender.
Please re-open if you still see this bug.
Thanks.

Comment 4

[Martin Stránský [:stransky] (ni? me)]

Note: this is fixed in Firefox 92/93.

Comment 5

[Erin of Yukis [:ntninja]]

No issues on Firefox 92b5 (neither rendering slowness nor slow popups) with Linux 5.12.0-16.2-liquorix-amd64 and KWin 5.21.5 anymore. Thanks!