Once I hit ALT+F2 and start typing into krunner the krunner CPU usage is increased to 80-90%. It does not go low until I kill krunner. This is reproducible always. Once I have disabled all modules (in krunner settings) that search through files, emails and contacts the krunner start behaving normally. Note: I have disabled baloo some time ago in system setting -> search -> file search It seems the guy here experience the same issue: https://forum.kde.org/viewtopic.php?f=289&t=132775
File search is run out-of-process since https://phabricator.kde.org/D7404 If krunner is still consuming 100% CPU, this is no filesearch issue. If the baloorunner helper is consuming 100% CPU, it is as filesearch/baloo issue. In this case, please reopen and move to component frameworks-baloo.