1683420 - Limit the number of WebGL X11 connections open simultaneously on Linux

Status: RESOLVED FIXED

(Core :: Graphics: CanvasWebGL, task)

Description

[Chris Peterson [:cpeterson]]

With Fission, users and sites can open an unlimited number of content processes. Each content process might use WebGL and need its own X11 connection. However Linux has a system-wide limit (256) on the number of X11 connections shared by all X11 applications.

We want Firefox to be a polite X11 citizen and not open too many X11 connections that might cause the system to hit its limit (which can cause system-wide crashes or hangs).

The ideal solution is WebGL remoting (bug 1638466), which will consolidate all WebGL X11 usage into one process. But WebGL remoting on Linux is blocked by some other Linux problems (like crash reporting bug 1678152 and Nouveau GPU crash bug 1671054).

Until we have WebGL remoting on Linux, this bug proposes we limit the number of WebGL X11 connections open simultaneously. Jeff Gilbert said in email:

I think we can keep the browser limited to 30ish webgl context-having-origins without any real issue. It's a little bit of work, but pretty tractable.

Auto-closing connections is useful too, but having forcible connection reclamation is probably 90% as good as remote WebGL for Fission. (from a User perspective)

See also bug 1673705 to auto-close unused WebGL X11 connections.

Comment 1

[Chris Peterson [:cpeterson]]

Nika doesn't think capping the number of WebGL X11 connections needs to block Fission MVP. Non-native theming will remove the biggest use of X11 in content processes and Nika thinks that's probably good enough

Comment 2

[Gian-Carlo Pascutto [:gcp]]

We're shipping bug 1129492.