My guess is your systemd service isn’t exiting and so the shutdown pauses until your service exits or after a timeout, the service is sent a kill signal to exit.
Regards, John > On Jun 2, 2016, at 3:28 PM, YP66 <[email protected]> wrote: > > I am working on an automatic shutdown based on an external signal (through a > digital IO line), on a BB black, running Debian Jessie. > > I build a program that monitors the digital line and when that line goes > high, the program calls > system("/sbin/shutdown -h now"); > > When I run that program interactively, it takes anywhere between 6 to 10 > seconds to shutdown following the digital line flip. I use an LED to tell me > when the process detects the bit flip so I can reliably count the time to > shutdown. The actual shutdown is evident because all the lights go off. At > that point I have to recycle power to start again, which is exactly what I > want. > > However, when I put the same program to run as a service (by adding a service > in /lib/systemd/ and using systemctl to start it), the system takes over 30 > seconds to shutdown, sometimes a minute or two. I know the program is > running as a service because I can see the LED I am using as feedback. The > LED changes blink rate when the 'service' detects the GPIO change so I can > tell the program is getting to the point of making the system call, it just > takes so much longer. In fact, initially I thought it did not work, only to > have the system shutdown on my suddenly a couple of minutes later. > > So the situation is that a program running directly goes through a shutdown > almost instantaneously but when run through a service, it takes significantly > longer. Any idea why? > > By the way, I have also tried > > sync(); > reboot(LINUX_REBOOT_CMD_POWER_OFF); > > instad of system("/sbin/shutdown -h now'), and I get more or less the same > behavior. > > > > -- > For more options, visit http://beagleboard.org/discuss > <http://beagleboard.org/discuss> > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] > <mailto:[email protected]>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/beagleboard/501fb3a7-bdae-4b3e-96ad-3df2a8c67d0e%40googlegroups.com > > <https://groups.google.com/d/msgid/beagleboard/501fb3a7-bdae-4b3e-96ad-3df2a8c67d0e%40googlegroups.com?utm_medium=email&utm_source=footer>. > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/851E8C7F-D358-4E95-9016-42475441363C%40gmail.com. For more options, visit https://groups.google.com/d/optout.
