On 2 April 2013 09:11, Mark Rogers mark@quarella.co.uk wrote:
CPU was at ~100% this morning; the PC's been unused (but left running) since Thursday.
OK, so this is weird.
After sending the last email, I started killing apps one at a tme to see if I could find anything that reduced X CPU usage. The "obvious" apps like Chrome and Firefox (both of which were open, both of which had dozens of tabs open) had no impact.
Killing dropbox resulted in an instant drop of CPU usage from 100% to 0%.
Further research shows that when Dropbox is performing a sync, it shows an animated tray icon and CPU usage goes to 100%. On completion it reverts to a static "green tick" icon and CPU usage goes back to normal. However, if (as I had) you have an unreadable file in your Dropbox folder, the sync fails and the animated icon remains, causing CPU usage to stay at 100%.
The problem is presumably in system tray somewhere. I found this thread: http://forum.kde.org/viewtopic.php?f=67&t=110294 .. where someone else is having the same problem, although it's not clear that Dropbox is relevant in his case.
This KDE bug looks relevant: https://bugs.kde.org/show_bug.cgi?id=313803
More digging needed I think.