100% CPU Usage Bug for me under Linux with 4 x 5870 with Catalyst 11.11 fixed !
Finally.
Not for me.
Ubuntu 11.10 64 bits
Catalyst 11.11
CGMiner 2.0.8
CGMiner consumes 120% of my CPU (core2 duo).
I'll fallback to Ubuntu 11.04 + Catalyst 11.6 + AMDAPPSDK v2.4 and CGMiner 2.0.6.
I've noticed this behaviour when using the opencl headers provided by debian and the ICD provided with the 11.11 drivers (package amd-opencl-icd in debian). Installed the app sdk from
http://forums.amd.com/forum/messageview.cfm?catid=390&threadid=125792 instead and the CPU usage is down to ~10%. (This is on a 64bit debian testing with the 11.11 driver from the repos.)