A small breakthrough today: I discovered the issue is not compiz, it's just the unity plugin. The tearing stops when you disable the unity plugin. The same is true for performance bug 861061.
Both issues seem to be caused by an unreasonable amount of overhead that the unity plugin introduces into compiz. And both issues are new in Ubuntu 11.10, so it's a regression.
A small breakthrough today: I discovered the issue is not compiz, it's just the unity plugin. The tearing stops when you disable the unity plugin. The same is true for performance bug 861061.
Both issues seem to be caused by an unreasonable amount of overhead that the unity plugin introduces into compiz. And both issues are new in Ubuntu 11.10, so it's a regression.