moving windows causes the top bar and the launcher bar to flicker

[Silviu C.]

As the title says, when I grab a window and move it around the top bar and the launcher disappear and then re-appear. Unity does not crash. During the move these elements flicker on and off. It looks more like a graphical glitch.

This seems to have started after I got the packages that introduced the anti-aliased window corners.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: unity 7.1.2+14.04.20140220-0ubuntu1
ProcVersionSignature: Ubuntu 3.13.0-11.31-generic 3.13.3
Uname: Linux 3.13.0-11-generic x86_64
NonfreeKernelModules: nvidia
.proc.driver.nvidia.gpus.0: Error: [Errno 21] Is a directory: '/proc/driver/nvidia/gpus/0'
.proc.driver.nvidia.registry: Binary: ""
.proc.driver.nvidia.version:
 NVRM version: NVIDIA UNIX x86_64 Kernel Module 331.38 Wed Jan 8 19:32:30 PST 2014
 GCC version: gcc version 4.8.2 (Ubuntu 4.8.2-16ubuntu1)
.tmp.unity.support.test.0:

ApportVersion: 2.13.2-0ubuntu5
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: Mon Feb 24 09:49:18 2014
DistUpgraded: Fresh install
DistroCodename: trusty
DistroVariant: ubuntu
GraphicsCard:
 NVIDIA Corporation GK106 [GeForce GTX 660] [10de:11c0] (rev a1) (prog-if 00 [VGA controller])
   Subsystem: ASUSTeK Computer Inc. Device [1043:843b]
InstallationDate: Installed on 2014-02-13 (10 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Alpha amd64 (20140111)
MachineType: System manufacturer System Product Name
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-11-generic root=UUID=c59b4ac8-ab41-40df-aa23-ee39891ed79c ro quiet splash
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 10/27/2011
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 1104
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: P8P67 LE
dmi.board.vendor: ASUSTeK COMPUTER INC.
dmi.board.version: Rev X.0X
dmi.chassis.asset.tag: Asset-1234567890
dmi.chassis.type: 3
dmi.chassis.vendor: Chassis Manufacture
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1104:bd10/27/2011:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKCOMPUTERINC.:rnP8P67LE:rvrRevX.0X:cvnChassisManufacture:ct3:cvrChassisVersion:
dmi.product.name: System Product Name
dmi.product.version: System Version
dmi.sys.vendor: System manufacturer
version.compiz: compiz 1:0.9.11+14.04.20140218-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.52-1
version.libgl1-mesa-dri: libgl1-mesa-dri 10.1.0~rc1-1ubuntu4
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 10.1.0~rc1-1ubuntu4
version.nvidia-graphics-drivers: nvidia-graphics-drivers N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.15.0-1ubuntu6
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.8.2-1ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.3.0-1ubuntu2
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: Mon Feb 24 09:44:57 2014
xserver.configfile: default
xserver.errors: open /dev/fb0: No such file or directory
xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:

xserver.version: 2:1.15.0-1ubuntu6

[Silviu C. (silviucc)]

The workaround that I found was to disable flipping in nvidia-settings but this shouldn't be a permanent fix because it potentially degrades OpenGL performance:

Option "NoFlip" "boolean"

    Disable OpenGL flipping; see Chapter 17 for a description. Default: OpenGL
    will swap by flipping when possible.

[...]

   o Flipping: When OpenGL flipping is enabled, OpenGL can perform buffer
     swaps by changing which buffer the DAC scans out rather than copying the
     back buffer contents to the front buffer; this is generally a much higher
     performance mechanism and allows tearless swapping during the vertical
     retrace (when __GL_SYNC_TO_VBLANK is set). The conditions under which
     OpenGL can flip are slightly complicated, but in general: on GeForce or
     newer hardware, OpenGL can flip when a single full screen unobscured
     OpenGL application is running, and __GL_SYNC_TO_VBLANK is enabled.
     Additionally, OpenGL can flip on Quadro hardware even when an OpenGL
     window is partially obscured or not full screen or __GL_SYNC_TO_VBLANK is
     not enabled.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Alberto Salvia Novella (es20490446e)]

It renders essential functionality of the package (or a dependent one) broken.

[Ryan Nunes (rynunes)]

Silviu, the workaround does stop the flickering, however it introduces a different issue. After opening the unity launcher and closing it dragging any window at the top of the screen near the launcher causes bad tearing/glitching. Ubuntu/Unity 14.04 is pretty much unusable right now on a nvidia 770 and 760 as the opensource drivers do not perform well with these video cards.

[Silviu C. (silviucc)]

I found out that it ceases to act up when using the native Steam client. Starts to flicker when moving windows when I quit the Steam client.

[Silviu C. (silviucc)]

This does not appear to happen with driver version 340.46 installed using the .run installer.