Linux and The Crashy Firefox 4

by Susan Linton - Mar. 08, 2011Comments (2)

Firefox Several articles have been circulating around the Web concerning the crashing of Firefox 4 and urging users to upgrade their drivers. Most of these posts speak of Direct2D and Windows Layers acceleration issues, so Linux users may think they are exempt. However, this isn't entirely true.

Due to the rash of crash reports, Mozilla has compiled a blacklist blocking the hardware acceleration of Firefox 4 in certain hardware and driver combinations in common use. This list is long on Windows entries and even Mac is covered, but many Linux users may find their drivers blacklisted as well. But for the brave and tolerant, this blacklist can be overridden.

XRender is used to speed up basic content (text, images, CSS formatting) on the Web, and since it uses Cairo there doesn't seem to be an issue with it. However, OpenGL is effected. OpenGL handles things like layered content such as embedded video that has, for example, nice frames, "pop out," or "dim the lights" features. OpenGL has been blacklisted for all hardware not using NVIDIA proprietary drivers. All other drivers seem to crash too much. WebGL is used to speed up Javascript 3D objects. It uses OpenGL, so for those not using NVIDIA drivers are out of luck.

However, you can by-pass the blacklisting with a simple environmental variable. If you'd like to use these accelerated features against advice start Firefox 4 with the command: MOZ_GLX_IGNORE_BLACKLIST=1 firefox. You can also probably add the variable to any icon configuration or menu file.

Layers acceleration isn't enabled by default because it isn't exactly finished for Linux systems although NVIDIA driver users are reportedly having good luck with it. For those that would like to enable it type about:config in the Firefox address bar and change layers.acceleration.force-enabled=false to layers.acceleration.force-enabled=true.