[systemd-devel] Control process

[Marcos Felipe Rasia de Mello]

2013/12/27 Lennart Poettering <lennart at poettering.net>:
> On Fri, 27.12.13 10:39, Marcos Felipe Rasia de Mello (marcosfrm at gmail.com) wrote:
>
>> systemctl man page defines "kill --kill-who=control" as "kill [..] the
>> control process". What is this control process? ExecStartPre=
>> processes? These are killed automatically before ExecStart= according
>> to https://bugzilla.redhat.com/show_bug.cgi?id=818381 , right?
>
> control processes are the processes that systemd starts for a service
> that are not the main process. There can only be one control process and
> one main process at the same time at max. Control processes are
> basically all those mentioned in ExecStartPre=, ExecStartPost=,
> ExecReload=, ExecStop=, ... In some cases also the one from ExecStart=
> if the daemon first has to double fork to become the main service
> process.
>
> kill --kill-who=control is particularly useful for ExecReload= or
> ExecStartPost= where you might have both a control and a main process
> running. It's even useful for ExecStartPre= since you might have started
> a process with that which forked a couple of times, and you explicitly
> just want to kill the original control process you forked, not the
> children.
>

Excellent. Thank you.