Occasionally my desktop slows down a lot. The mouse pointer moves slowly or not at all, my fan starts whirring, and the end is generally nigh. If I'm very patient normality usually restores itself, but this happens daily.
Recently when it happened I switched to a TTY (Ctrl-Alt-F1) and ran
top. It revealed that the processes
ibus-ui-gtk3 were using 99% and 100% of the CPU respectively.
Maths notwithstanding, how can I find out what these processes are doing at the time?