I just upgraded my trusty system and the X11 / unity7 screen turned black for ~200ms twice during the upgrade; it appeared roughly when the systemd-logind services were stopped and started in this log. Music playing via youtube in firefox kept playing without issue and the X11 session otherwise seemed unaffected but it certainly was jarring.
Thanks
The following packages will be upgraded:
flashplugin-installer gir1.2-gudev-1.0 libgudev-1.0-0 libpam-systemd
libsystemd-daemon0 libsystemd-journal0 libsystemd-login0 libudev1
libudev1:i386 systemd-services udev
11 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 1,138 kB of archives.
After this operation, 1,024 B of additional disk space will be used.
Do you want to continue? [Y/n]
Get:1 http://mirrors.kernel.org/ubuntu/ trusty-updates/main udev amd64 204-5ubuntu20.18 [734 kB]
Get:2 http://security.ubuntu.com/ubuntu/ trusty-security/multiverse flashplugin-installer amd64 11.2.202.569ubuntu0.14.04.1 [6,852 B]
Get:3 http://mirrors.kernel.org/ubuntu/ trusty-updates/main libudev1 i386 204-5ubuntu20.18 [34.4 kB]
Get:4 http://mirrors.kernel.org/ubuntu/ trusty-updates/main libudev1 amd64 204-5ubuntu20.18 [33.5 kB]
Get:5 http://mirrors.kernel.org/ubuntu/ trusty-updates/main libpam-systemd amd64 204-5ubuntu20.18 [25.5 kB]
Get:6 http://mirrors.kernel.org/ubuntu/ trusty-updates/main systemd-services amd64 204-5ubuntu20.18 [197 kB]
Get:7 http://mirrors.kernel.org/ubuntu/ trusty-updates/main libsystemd-daemon0 amd64 204-5ubuntu20.18 [10.0 kB]
Get:8 http://mirrors.kernel.org/ubuntu/ trusty-updates/main libsystemd-login0 amd64 204-5ubuntu20.18 [27.0 kB]
Get:9 http://mirrors.kernel.org/ubuntu/ trusty-updates/main libgudev-1.0-0 amd64 1:204-5ubuntu20.18 [14.1 kB]
Get:10 http://mirrors.kernel.org/ubuntu/ trusty-updates/main libsystemd-journal0 amd64 204-5ubuntu20.18 [49.9 kB]
Get:11 http://mirrors.kernel.org/ubuntu/ trusty-updates/main gir1.2-gudev-1.0 amd64 1:204-5ubuntu20.18 [5,496 B]
Fetched 1,138 kB in 0s (1,162 kB/s)
Preconfiguring packages ...
(Reading database ... 307737 files and directories currently installed.)
Preparing to unpack .../udev_204-5ubuntu20.18_amd64.deb ...
Adding 'diversion of /bin/udevadm to /bin/udevadm.upgrade by fake-udev'
Unpacking udev (204-5ubuntu20.18) over (204-5ubuntu20.15) ...
Preparing to unpack .../libudev1_204-5ubuntu20.18_i386.deb ...
De-configuring libudev1:amd64 (204-5ubuntu20.15) ...
Unpacking libudev1:i386 (204-5ubuntu20.18) over (204-5ubuntu20.15) ...
Preparing to unpack .../libudev1_204-5ubuntu20.18_amd64.deb ...
Unpacking libudev1:amd64 (204-5ubuntu20.18) over (204-5ubuntu20.15) ...
Preparing to unpack .../libpam-systemd_204-5ubuntu20.18_amd64.deb ...
systemd-logind stop/waiting
Unpacking libpam-systemd:amd64 (204-5ubuntu20.18) over (204-5ubuntu20.15) ...
Preparing to unpack .../systemd-services_204-5ubuntu20.18_amd64.deb ...
Unpacking systemd-services (204-5ubuntu20.18) over (204-5ubuntu20.15) ...
Preparing to unpack .../libsystemd-daemon0_204-5ubuntu20.18_amd64.deb ...
Unpacking libsystemd-daemon0:amd64 (204-5ubuntu20.18) over (204-5ubuntu20.15) ...
Preparing to unpack .../libsystemd-login0_204-5ubuntu20.18_amd64.deb ...
Unpacking libsystemd-login0:amd64 (204-5ubuntu20.18) over (204-5ubuntu20.15) ...
Preparing to unpack .../libgudev-1.0-0_1%3a204-5ubuntu20.18_amd64.deb ...
Unpacking libgudev-1.0-0:amd64 (1:204-5ubuntu20.18) over (1:204-5ubuntu20.15) ...
Preparing to unpack .../libsystemd-journal0_204-5ubuntu20.18_amd64.deb ...
Unpacking libsystemd-journal0:amd64 (204-5ubuntu20.18) over (204-5ubuntu20.15) ...
Preparing to unpack .../flashplugin-installer_11.2.202.569ubuntu0.14.04.1_amd64.deb ...
Unpacking flashplugin-installer (11.2.202.569ubuntu0.14.04.1) over (11.2.202.559ubuntu0.14.04.1) ...
Preparing to unpack .../gir1.2-gudev-1.0_1%3a204-5ubuntu20.18_amd64.deb ...
Unpacking gir1.2-gudev-1.0 (1:204-5ubuntu20.18) over (1:204-5ubuntu20.15) ...
Processing triggers for man-db (2.6.7.1-1ubuntu1) ...
Processing triggers for ureadahead (0.100.0-16) ...
Processing triggers for update-notifier-common (0.154.1ubuntu1) ...
flashplugin-installer: downloading http://archive.canonical.com/pool/partner/a/adobe-flashplugin/adobe-flashplugin_20160209.1.orig.tar.gz
Installing from local file /tmp/tmpmN_J4k.gz
Flash Plugin installed.
Setting up libudev1:amd64 (204-5ubuntu20.18) ...
Setting up libudev1:i386 (204-5ubuntu20.18) ...
Setting up udev (204-5ubuntu20.18) ...
udev stop/waiting
udev start/running, process 21523
Removing 'diversion of /bin/udevadm to /bin/udevadm.upgrade by fake-udev'
update-initramfs: deferring update (trigger activated)
Setting up libsystemd-daemon0:amd64 (204-5ubuntu20.18) ...
Setting up systemd-services (204-5ubuntu20.18) ...
Setting up libpam-systemd:amd64 (204-5ubuntu20.18) ...
systemd-logind start/running, process 21592
Setting up libsystemd-login0:amd64 (204-5ubuntu20.18) ...
Setting up libgudev-1.0-0:amd64 (1:204-5ubuntu20.18) ...
Setting up libsystemd-journal0:amd64 (204-5ubuntu20.18) ...
Setting up flashplugin-installer (11.2.202.569ubuntu0.14.04.1) ...
Setting up gir1.2-gudev-1.0 (1:204-5ubuntu20.18) ...
Processing triggers for libc-bin (2.19-0ubuntu6.6) ...
Processing triggers for initramfs-tools (0.103ubuntu4.2) ...
update-initramfs: Generating /boot/initrd.img-3.13.0-77-generic
ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: libsystemd-login0 204-5ubuntu20.15
ProcVersionSignature: Ubuntu 3.13.0-77.121-generic 3.13.11-ckt32
Uname: Linux 3.13.0-77-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.19
Architecture: amd64
CurrentDesktop: Unity
Date: Tue Feb 9 17:58:17 2016
InstallationDate: Installed on 2012-10-18 (1209 days ago)
InstallationMedia: Ubuntu 12.04.1 LTS "Precise Pangolin" - Release amd64 (20120823.1)
SourcePackage: systemd
UpgradeStatus: Upgraded to trusty on 2014-04-12 (669 days ago)
I noticed after leaving my computer idle for a few hours that the screen did not blank; I think my xset dpms settings were forgotten during these blips. (I know that's a large jump to make, but I'm pretty sure my screen turned off normally yesterday after a few minutes of idle time. The event described here was certainly unusual.)
Thanks