* when breaking cycles drop sysv services first, then services from /run, then from /etc, then from /usr
* readahead: when bumping /sys readahead variable save mtime and compare later to detect changes
* when breaking cycles drop sysv services first, then services from /run, then from /etc, then from /usr
* readahead: when bumping /sys readahead variable save mtime and compare later to detect changes