[systemd-devel] [RFC] core: introduce ExitOnIdle= and ExitOnIdleSec=

[Lennart Poettering]

On Mon, 20.04.15 23:56, WaLyong Cho (walyong.cho at samsung.com) wrote:

> If a service does not consume CPU during some time(can be configured
> by ExitOnIdleSec=) and set to stopped on idle state(ExitOnIdle=), the
> service will be stopped. This can be useful if the service provides
> some of activation methods.

Hmm, I am not convinced this would be a good idea, sorry.

The crux of the issue is that it is really hard to detect from the
outside if a daemon is really idle. Only the daemon itself knows
whether it is truly idle or not. I mean, it could just be waiting for
some timer to elapse, or some other external event.

I doubt this is really useful unless you have really really simple
daemons that purely react on client requests and nothing else, and you
know the codebase and that it is OK to terminate the daemon just
because its CPU usage is zero. But if you know the codebase that well
it would probably be a better idea to just add support for
exit-on-idle directly to the daemon in question.

exit-on-idle is really something that should be implemented *in* the
daemon, and not done externally!

Sorry,

Lennart

-- 
Lennart Poettering, Red Hat