Ubuntu desktop hangs

[Sami Pietila]

After a couple of days of usage (no machine restart / shutdown) the ubuntu desktop start to hang for minutes. For example, opening a window takes several minutes and during that time the desktop is unresponsive.

When desktop starts to slow, running "compiz --replace" command takes several minutes, but after it is done, the desktop is ok again for a couple of days.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: compiz 1:0.9.11+14.04.20140423-0ubuntu1
ProcVersionSignature: Ubuntu 3.13.0-29.53-generic 3.13.11.2
Uname: Linux 3.13.0-29-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 2.14.1-0ubuntu3.2
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: compiz
CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
CompositorUnredirectFSW: true
CurrentDesktop: Unity
Date: Fri Jun 13 11:16:06 2014
DistUpgraded: 2014-04-11 11:51:55,755 DEBUG enabling apt cron job
DistroCodename: trusty
DistroVariant: ubuntu
GraphicsCard:
 Subsystem: Hewlett-Packard Company Device [103c:18e4]
 Advanced Micro Devices, Inc. [AMD/ATI] Caicos XTX [Radeon HD 8490 / R5 235X OEM] [1002:6771] (prog-if 00 [VGA controller])
   Subsystem: Hewlett-Packard Company Device [103c:90b8]
InstallationDate: Installed on 2013-11-05 (219 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1)
MachineType: Hewlett-Packard HP EliteDesk 800 G1 TWR
PackageArchitecture: all
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-29-generic.efi.signed root=UUID=ef4f067e-192b-4f3f-873d-bfb295641eec ro quiet splash vt.handoff=7
SourcePackage: compiz
UpgradeStatus: Upgraded to trusty on 2014-04-11 (62 days ago)
dmi.bios.date: 09/09/2013
dmi.bios.vendor: Hewlett-Packard
dmi.bios.version: L01 v02.18
dmi.board.asset.tag: CZC3427KBP
dmi.board.name: 18E4
dmi.board.vendor: Hewlett-Packard
dmi.chassis.asset.tag: CZC3427KBP
dmi.chassis.type: 6
dmi.chassis.vendor: Hewlett-Packard
dmi.modalias: dmi:bvnHewlett-Packard:bvrL01v02.18:bd09/09/2013:svnHewlett-Packard:pnHPEliteDesk800G1TWR:pvr:rvnHewlett-Packard:rn18E4:rvr:cvnHewlett-Packard:ct6:cvr:
dmi.product.name: HP EliteDesk 800 G1 TWR
dmi.sys.vendor: Hewlett-Packard
version.compiz: compiz 1:0.9.11+14.04.20140423-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.52-1
version.libgl1-mesa-dri: libgl1-mesa-dri 10.1.3-0ubuntu0.1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 10.1.3-0ubuntu0.1
version.xserver-xorg-core: xserver-xorg-core 2:1.15.1-0ubuntu2
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.8.2-1ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.3.0-1ubuntu3.1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.910-0ubuntu1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.10-1ubuntu2
xserver.bootTime: Wed Jun 11 10:15:35 2014
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.version: 2:1.15.1-0ubuntu2
xserver.video_driver: radeon

[Sami Pietila (sampie)]

During compiz restart, there is also confusing messages whether unity is supported by the hardware or not.

...
compiz (core) - Info: Loading plugin: composite
compiz (core) - Info: Starting plugin: composite
compiz (core) - Info: Loading plugin: opengl
compiz (core) - Info: Unity is fully supported by your hardware.
compiz (core) - Info: Unity is not supported by your hardware. Enabling software rendering instead (slow).
compiz (core) - Info: Starting plugin: opengl
...

[Sami Pietila (sampie)]

This seems to be 14.04 LTS specific issue. The problem is has not been occurring after upgrading to 14.10.