[regression] Compiz wakes up 200Hz while the screen is locked

I noticed my laptop fan going crazy while the screen is locked. But logging in via ssh showed it's mostly CPU-idle according to top. Powertop on the other hand shows compiz is spinning at 200 wakeups per second.

I seem to recall that 200 Hz is the upper limit in Compiz, designed to throttle it when SwapBuffers is failing to so.

Maybe we need to do some work in our Mir client logic for SwapBuffers then. As I am using XMir and unity-system-compositor.

ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: compiz 1:0.9.9~daily13.04.18.1~13.04-0ubuntu1
ProcVersionSignature: Ubuntu 3.9.0-6.14-generic 3.9.6
Uname: Linux 3.9.0-6-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 2.10.2-0ubuntu2
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
Date: Mon Jun 24 13:51:47 2013
DistUpgraded: Fresh install
DistroCodename: saucy
DistroVariant: ubuntu
GraphicsCard:
 Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller [8086:0126] (rev 09) (prog-if 00 [VGA controller])
   Subsystem: Lenovo Device [17aa:21da]
InstallationDate: Installed on 2013-06-11 (12 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Alpha amd64 (20130611)
MachineType: LENOVO 4286CTO
MarkForUpload: True
PackageArchitecture: all
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.9.0-6-generic root=UUID=25c27832-0efa-4fc4-8a14-41af68d008dc ro quiet splash vt.handoff=7
SourcePackage: compiz
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/11/2013
dmi.bios.vendor: LENOVO
dmi.bios.version: 8DET68WW (1.38 )
dmi.board.asset.tag: Not Available
dmi.board.name: 4286CTO
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvr8DET68WW(1.38):bd04/11/2013:svnLENOVO:pn4286CTO:pvrThinkPadX220:rvnLENOVO:rn4286CTO:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 4286CTO
dmi.product.version: ThinkPad X220
dmi.sys.vendor: LENOVO
version.compiz: compiz 1:0.9.9~daily13.04.18.1~13.04-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.45-2ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 9.2~git20130611.761320b1-0ubuntu0+mir3-jenkins81saucy0
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 9.2~git20130611.761320b1-0ubuntu0+mir3-jenkins81saucy0
version.xserver-xorg-core: xserver-xorg-core 2:1.13.3+xmir1-0
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.7.3-0ubuntu2b2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.1.0+xmir2504-0~saucy1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.21.9+xmir5862-0~saucy1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.8+xmir2338-0~saucy1
xserver.bootTime: Mon Jun 24 13:49:26 2013
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:

xserver.version: 2:1.13.3+xmir1-0