Version:            (using KDE 4.2.2)
OS:                Linux
Installed from:    Ubuntu Packages

I set up my KDE 4.2.2 desktop to use a slideshow as the desktop background. I selected a folder that contains about 8'000 pictures in about 140 subdirectories.

Now, plasma hangs for about 15 seconds each time I do one of the following things:

- Login into KDE (the hang happens while the desktop is loading)
- Open the Desktop settings dialog box
- try to change any of the "position", "color" settings
- try to change the folder in which the pictures are located

I set the slideshow to change the picture every minute. I now see a spike in CPU load (in the system monitor plasmoid) every minute as the picture changes (not sure if this is related, it might just be because the picture is loaded and scaled)

I suspect this hang is caused by plasma rebuilding the list of files available for the slideshow (dolphin seems to take about the same time to display the file count in my photo folder's properties). If that's the case, maybe the file list can be cached to a file somewhere in home folder and reloaded periodically in a background thread instead of rebuilding that file list in the foreground thread at all those different occasions.