Scenario:
- running KDE 4.14.3 from FreeBSD ports on a FreeBSD 10.2 system
- analog clock widget shown on desktop
- usual panel components running, especially the taskbar
Result:
- when moving the cursor across various desktop items, e.g., the analog clock, all items handled by one of the kdeinit processes freeze for several hundred milliseconds
Expected result:
- plasma icons should quickly respond to focus changes etc.


Reproducible: Always


Actual Results:  
Result:
- when moving the cursor across various desktop items, e.g., the analog clock, all items handled by one of the kdeinit processes freeze for several hundred milliseconds


Expected Results:  
Expected result:
- plasma icons should quickly respond to focus changes etc.


I traced the kdeinit process exhibiting the highest cpu load and found out that it was traversing all known icon directories in search for an xload and an xterm icon. No such icons (at least by the names being searched for) exist on the system.
I then added an xload.png and an xterm.png to /usr/local/share/pixmaps; the cpu usage of the kdeinit process dropped considerably, and the delays in maintaining the plasma desktop vanished.
For newly spawned xterms and xloads, the taskbar now displays the newly installed icons instead of the default X window symbol. This leads me to suspect that it is the taskbar which is the culprit.

Recommended fix: If an icon cannot be found, the taskbar should stop searching for it instead of repeating the search whenever there is desktop activity.