Public bug reported: Ubuntu 17.04 systemd: 232-21ubuntu2
short: Systemd on reboot waits extra 90sec for no reason Other references: https://forum.openvz.org/index.php?t=tree&goto=52177&S=0012de5a5151a907e13af2b5267cf59d Env: OpenVZ 2.6.32-openvz-042stab120.19-amd64 Ubuntu 17.04 Packages: # dpkg -l | grep systemd ii libsystemd0:amd64 232-21ubuntu2 amd64 systemd utility library ii systemd 232-21ubuntu2 amd64 system and service manager ii systemd-sysv 232-21ubuntu2 amd64 system and service manager - SysV links console log during "problem" ================= Sending SIGTERM to remaining processes...^M Sending SIGKILL to remaining processes...^M Sending SIGKILL to PID 338 (systemd-cgroups).^M Sending SIGKILL to PID 339 (systemd-cgroups).^M system-shutdown succeeded.^M Rebooting.^M ================= The "extra" wait is occurring before line: system-shutdown succeeded Problem analysis, steps: 1. PID 1 does exec to /lib/systemd/systemd-shutdown 2. src/core/shutdown.c:main calls broadcast_signal(SIGKILL, true, false); 3. somehow /lib/systemd/systemd-cgroups-agent is started by /sys/fs/cgroup/systemd/release_agent 4. src/core/killall.c:broadcast_signal calls killall(sig, pids, send_sighup); writes message: Sending SIGKILL to PID 338 (systemd-cgroups). adds pid 338 to pids sed 5. broadcast_signal calls wait_for_children(pids, &mask); 6. in paralel process systemd-cgroups finishes 7. we still in wait_for_children and stuck here for 90 sec Tried workaround approaches: 1. mount /dev/null -o bind /lib/systemd/systemd-cgroups-agent will not work, before shutdown mounts are umounted, so we lose that one 2. change /sys/fs/cgroup/systemd/release_agent to /bin/false still caches running false process and waits 90 sec for finish of it 3. write 0 to /sys/fs/cgroup/systemd/notify_on_release from script in /lib/systemd/system-shutdown this is to late, those scripts runs after long delay Simple proposed workaround: disable notify before systemd-shutdown by using wrapper script dpkg-divert --add /lib/systemd/systemd-shutdown mv /lib/systemd/systemd-shutdown /lib/systemd/systemd-shutdown.distrib cat > /lib/systemd/systemd-shutdown <<EOF #!/bin/sh echo 0 > /sys/fs/cgroup/systemd/notify_on_release exec /lib/systemd/systemd-shutdown.distrib "$@" EOF chmod +x /lib/systemd/systemd-shutdown ** Affects: systemd (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1725685 Title: Systemd long reboot on OpenVZ To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1725685/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
