On 2020-12-07, Harald Dunkel <ha...@afaics.de> wrote: > About the PIDs: Maybe a systctl like > > kernel.pid_max = 4194303 > > known from other OSes could help to reduce the risk for PID conflicts.
This doesn't help if you actually want reliability, rather than just "reliable most of the time". There were also some concerns about what software would do with long PIDs - even on a very basic level that adds another couple of columns to top(1) output. > If you store the PID files on a volatile file system, so you can be sure > they are gone on the next reboot, anyway. /var/run is cleared at boot anyway - the problem is pid reuse during uptime of the system. One can check that the new pid is owned by a process of the correct name - but then the problem returns, the process name doesn't have enough information to uniquely identify it. And if that is fixed there's no need to save the pid. So if there's a problem to be fixed, it is to get the information into the other process string..
