[systemd-devel] systemd "hangs" for several minutes on shutdown if it gets "service force-reload" request

[Lennart Poettering]

On Fri, 14.01.11 09:19, Tollef Fog Heen (tfheen at err.no) wrote:

> 
> ]] Lennart Poettering 
> 
> | > What I wonder in this case, why vnstat.service/reload appears to hang
> | > in this case? The job itself fails during startup (initscript is
> | > disabled, so it gets indirect request from ifup and does nothing):
> | 
> | Does this probelm still exist?
> | 
> | Most likely this is simply an ordering deadlock: systemd executes
> | something that asks systemd to execute something else which however is
> | order after the first unit. That is is not really fixable. At least I
> | am have no idea what we could do about this.
> 
> We should at least print out/log what's happening when this happens.

Detecting deadlocks is hard. (heck, the halting problem is
undecidable). Not sure how much we realistically can do.

> Slightly related, it'd be really nice if we could have a way to poke
> systemd to dump state.  I'm trying to track down a problem where boot
> takes a while, and spawning extra shells and using serial consoles kinda
> work, but it doesn't work that great.

"systemctl dump" might help. "systemctl list-jobs" too.

Lennart

-- 
Lennart Poettering - Red Hat, Inc.