GNOME Bugzilla – Bug 520792
[RFE] metacity should warn user that composite won't work with Xinerama on Nvidia
Last modified: 2008-03-07 07:07:36 UTC
Recently upgrading to Ubuntu Hardy to test out new gnome features, I tried out the metacity compositer. After enabling /apps/metacity/general/compositing_manager nothing happened. metacity --replace gave the following warning: Window manager warning: Missing composite extension required for compositing $ lspci | grep VGA 01:00.0 VGA compatible controller: nVidia Corporation Quadro FX 1700 (rev a1) 02:00.0 VGA compatible controller: nVidia Corporation Quadro FX 1700 (rev a1) $ grep \"Composite\" /var/log/Xorg.0.log (**) Extension "Composite" is enabled Not sure if there is a better way to figure out if you are running composite or not, but that is misleading. Nvidia cards don't support composite with Xinerama enabled. It would be nice if metacity displayed a warning about composite not working with Nvidia drivers + Xinerama.
What should we do-- a printed warning? A dialogue box, maybe?
If this comment dupes lateron, it is because bugzilla via email is slow and not updating I was thinking just a warning in the terminal. It would go in .xsession-errors but that might not be the most friendly way to fix things. Dialog boxes are normally annoying, but this is a good idea also. Is doing both overkill?
I'm currently looking at a Xinerama display running on an NVidia card with metacity's compositing enabled and things work as expected... This is on Gentoo, though. The NVidia card is a GeForce 6600, and I'm using NVidia's binary drivers. Metacity is at 2.21.8. I've configured this using NVidia's tool, selecting TwinView (which seems to be the way NVidia handles Xinerama?) Feel free to ask for more info.
Twinview != Xinerama. They look the same, but are not. The point of this bug was for metacity to mention why composite won't work when Xinerama is enabled. It was filed so other people don't run into the same problem I did before asking on IRC. If you disagree, feel free to close it.
It probably makes sense then to mention TwinView as a possible solution for people looking for Xinerama and compositing on NVidia cards in the warning message. Most of the applications that support Xinerama seem to handle TwinView in the same way, so for most people this is probably a good solution, even though it may not be a 100% match.