I don't think it is fixed, this is what I get with image 20130925.2 but still no reproducer. I took 2 photos, switched to Gallery then to the Application Lens and waited until the screen goes black.
pidstat: 09:12:45 UID PID cswch/s nvcswch/s Command ... 09:12:56 0 606 120.99 0.10 init 09:12:56 103 643 1.39 0.10 dbus-daemon 09:12:56 1000 680 95.54 0.00 surfaceflinger ... 09:12:56 32011 919 0.30 0.00 init ... 09:12:56 32011 1079 483.86 0.00 unity8 ... 09:12:56 0 5099 323.56 0.00 kworker/u:0 09:12:56 0 5894 173.27 0.00 kworker/u:1 ... 09:12:56 0 6939 19.11 0.79 kworker/0:1 ... health-check: CPU usage: PID Process USR% SYS% TOTAL% Duration 1079 unity8 36.59 16.00 52.59 10.00 (high load) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1219871 Title: when idle with screen blank, unity8 generates hundreds of context switches per second To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/unity8/+bug/1219871/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs