Description of problem: When compiz is enabled, and the cpu is pegged doing something (like parsing xml on a yum update), the whole desktop interface slows to a crawl (mouse, moving windows, dektop switching). Also, other apps slow down considerably (totem will start to skip). Version-Release number of selected component (if applicable): X Window System Version 7.1.1 Build ID: xorg-x11-server 1.1.1-43.fc6 Steps to Reproduce: 1. Turn on "Desktop Effects" 2. Start a high cpu activity 3. Observe sluggish mouse Actual results: Slow response time for all actions Expected results: System load should not effect mouse or interface response. Additional info: This is on decently fast cpu, and a nvidia card (running the beta 9625 drivers). My laptop (which has an integrated intel graphics chipset) doesn't have any problems like this. I realize this might just be the nvidia drivers causing trouble, but I figured I should document it, because I know other people are having the same problem.
Yeah, this is a general problem, and is therefore really hard to fix in the general case. If you have specific workloads that cause unreasonable CPU usage by the X server itself, please file those. But there's not much X can do if the kernel doesn't give it enough CPU time.