compiz (unity) uses too much CPU when pulsing an icon.

[Daniel van Vugt]

1. Start top or gnome-system-monitor so you can see CPU usage. Make sure the system is almost idle.
2. Plug in a thumb drive and make sure you can see the icon appear in the Unity Launcher.
3. Click on the thumb drive icon and watch CPU usage. It stays quite high for about 10 seconds before returning to normal.

On an Intel i7-2600, this causes compiz to use about 25% of one core for almost 10 seconds. Obviously excessive.

Strangely, if you navigate to the same thumb drive in a separate nautilus window then the CPU usage remains low. It seems the bug only happens when you click the device icon on the Unity Launcher.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: unity 3.8.16-0ubuntu1~natty1
ProcVersionSignature: Ubuntu 2.6.38-10.46-generic 2.6.38.7
Uname: Linux 2.6.38-10-generic x86_64
NonfreeKernelModules: fglrx
Architecture: amd64
CompizPlugins: [core,bailer,detection,composite,opengl,compiztoolbox,decor,vpswitch,place,imgpng,regex,unitymtgrabhandles,grid,session,snap,mousepoll,resize,move,animation,expo,ezoom,workarounds,resizeinfo,wall,staticswitcher,fade,scale,unityshell]
Date: Mon Aug 1 12:16:17 2011
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427.1)
ProcEnviron:
 LANGUAGE=en_AU:en
 LANG=en_AU.UTF-8
 SHELL=/bin/bash
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)

[Daniel van Vugt (vanvugt)]

OK, it's not specific to the device icons. The problem occurs while a launcher icon is pulsing. You can reproduce the bug if you launch Synaptic from the Launcher but then press Cancel, preventing it from loading. This makes the pulsing last much longer and uses significant CPU.