Xorg hung again while watching a video

[gregrwm]

This bug report is highly similar to Bug #1770250, except that this time i made sure to launch ubuntu-bug xserver-xorg before relaunching xorg, just in case that provides packaging of better information. This morning xorg froze again while watching a video. Watching a video seems to bring it on more than not, tho it does sometimes happen without watching a video. And FWIW i think fairly heavy swapping activity is also often involved in eliciting this hang bug. This morning, as in several earlier occurrences, the video image froze except that i was able to move the mouse cursor, however window borders did not change as they normally would when the mouse cursor travelled in and out of windows. Onscreen interactions such as trying to show the twm root menu or move or iconize windows, or keyboard keys such as ^L to the browser or even ctl-alt-F2 or ctl-alt-F3 all failed to produce their usual response. i was able to login via ssh, attach to tmux, and via htop observe that xorg was consuming around 95% CPU. i then sent signal 3 to xorg, after which ctl-alt-F2 and ctl-alt-F3 were again operational, and i found the attached report in /var/crash.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: xserver-xorg 1:7.7+19ubuntu7
ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17
Uname: Linux 4.15.0-20-generic x86_64
ApportVersion: 2.20.9-0ubuntu7
Architecture: amd64
BootLog:
 Skipping profile in /etc/apparmor.d/disable: usr.sbin.rsyslogd
  * Starting AppArmor profiles 
[ OK ]
  * Restoring resolver state... 
[ OK ]
CompositorRunning: None
Date: Fri May 11 10:44:23 2018
DistUpgraded: Fresh install
DistroCodename: bionic
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes
GraphicsCard:
 Intel Corporation 82Q35 Express Integrated Graphics Controller [8086:29b2] (rev 02) (prog-if 00 [VGA controller])
   Subsystem: Dell OptiPlex 755 [1028:0211]
   Subsystem: Dell OptiPlex 755 [1028:0211]
MachineType: Dell Inc. OptiPlex 755
ProcEnviron:
 LC_TIME=en_DK.utf8
 TERM=screen
 PATH=(custom, no user)
 LANG=en_US.utf8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/@bb/vmlinuz ro root=UUID=22e7c84a-a416-43e9-ae9d-ee0119fc3894 partroot=:b init=/etc/g/subroot subroot=@bb panic=30
SourcePackage: xorg
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/30/2008
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A10
dmi.board.name: 0PU052
dmi.board.vendor: Dell Inc.
dmi.chassis.type: 15
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA10:bd04/30/2008:svnDellInc.:pnOptiPlex755:pvr:rvnDellInc.:rn0PU052:rvr:cvnDellInc.:ct15:cvr:
dmi.product.name: OptiPlex 755
dmi.sys.vendor: Dell Inc.
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.91-2
version.libgl1-mesa-dri: libgl1-mesa-dri 18.0.0~rc5-1ubuntu1
version.libgl1-mesa-glx: libgl1-mesa-glx 18.0.0~rc5-1ubuntu1
version.xserver-xorg-core: xserver-xorg-core 2:1.19.6-1ubuntu4
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:18.0.1-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20171229-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.15-2
xserver.bootTime: Sat Feb 24 05:53:57 2018
xserver.configfile: default
xserver.devices:
 input Power Button KEYBOARD, id 6
 input Power Button KEYBOARD, id 7
 input Logitech Logitech USB Optical Mouse MOUSE, id 8
 input AT Translated Set 2 keyboard KEYBOARD, id 9
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:
 product id 16421
 vendor DEL
xserver.version: 2:1.19.6-1ubuntu1

[gregrwm (gregrwm)]

if there's a way for me to include debugging symbols or anything else helpful just say what and how.

[gregrwm (gregrwm)]

happened again today. same details. sent signal 3, attached the crash file.