The automatically-included information for this reports notes that I'm using kernel 4.8, where this issue doesn't occur. I don't have any other kernels to test with.
When the screen updates in 4.13 while running Compiz, it causes high CPU usage in a kworker thread. This was 30~40% of a CPU core on my system. This doesn't happen with other window managers tested, like Metacity, or whatever non-Compiz Gnome and Ubuntu use (gnome-shell maybe, though that 15% CPU load more than Metacity when I checked). Since Unity uses Compiz, it happens there as well as with 'Ubuntu flashback Compiz'.
This seems unrelated to how much of the screen is being repainted, as the 'Show Repaint' plugin in Compiz can show that only a few pixels are being updated and the kworker load is the same.
ProblemType: Bug
DistroRelease: Ubuntu 17.10
Package: linux-generic 4.13.0.25.26
ProcVersionSignature: Ubuntu 4.8.0-34.36-generic 4.8.11
Uname: Linux 4.8.0-34-generic x86_64
ApportVersion: 2.20.7-0ubuntu3.7
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/pcmC0D0p: misaki 1685 F...m pulseaudio
/dev/snd/controlC0: misaki 1685 F.... pulseaudio
CurrentDesktop: GNOME-Flashback:GNOME
Date: Sun Jan 21 00:17:16 2018
HibernationDevice: RESUME=UUID=ea8d7b22-9a3e-412e-af6a-8fc260a76a2c
MachineType: ASUSTeK Computer Inc. N50Vn
ProcFB: 0 nouveaufb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.8.0-34-generic root=UUID=b09dc720-93ec-4fdf-a42f-7ea19a9af555 ro quiet splash vt.handoff=7
RelatedPackageVersions:
linux-restricted-modules-4.8.0-34-generic N/A
linux-backports-modules-4.8.0-34-generic N/A
linux-firmware 1.169.1
SourcePackage: linux
UpgradeStatus: Upgraded to artful on 2018-01-09 (12 days ago)
WpaSupplicantLog:
dmi.bios.date: 03/05/2009
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 211
dmi.board.asset.tag: ATN12345678901234567
dmi.board.name: N50Vn
dmi.board.vendor: ASUSTeK Computer Inc.
dmi.board.version: 1.0
dmi.chassis.asset.tag: ATN12345678901234567
dmi.chassis.type: 10
dmi.chassis.vendor: ASUSTeK Computer Inc.
dmi.chassis.version: 1.0
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr211:bd03/05/2009:svnASUSTeKComputerInc.:pnN50Vn:pvr1.0:rvnASUSTeKComputerInc.:rnN50Vn:rvr1.0:cvnASUSTeKComputerInc.:ct10:cvr1.0:
dmi.product.name: N50Vn
dmi.product.version: 1.0
dmi.sys.vendor: ASUSTeK Computer Inc.
This duplicates the information in https:/ /bugs.launchpad .net/ubuntu/ +source/ compiz/ +bug/1744515. Filing this to get more exposure.
The automatically- included information for this reports notes that I'm using kernel 4.8, where this issue doesn't occur. I don't have any other kernels to test with.
When the screen updates in 4.13 while running Compiz, it causes high CPU usage in a kworker thread. This was 30~40% of a CPU core on my system. This doesn't happen with other window managers tested, like Metacity, or whatever non-Compiz Gnome and Ubuntu use (gnome-shell maybe, though that 15% CPU load more than Metacity when I checked). Since Unity uses Compiz, it happens there as well as with 'Ubuntu flashback Compiz'.
This seems unrelated to how much of the screen is being repainted, as the 'Show Repaint' plugin in Compiz can show that only a few pixels are being updated and the kworker load is the same.
ProblemType: Bug ature: Ubuntu 4.8.0-34.36-generic 4.8.11 controlC0: misaki 1685 F.... pulseaudio :GNOME UUID=ea8d7b22- 9a3e-412e- af6a-8fc260a76a 2c /boot/vmlinuz- 4.8.0-34- generic root=UUID= b09dc720- 93ec-4fdf- a42f-7ea19a9af5 55 ro quiet splash vt.handoff=7 ersions: restricted- modules- 4.8.0-34- generic N/A backports- modules- 4.8.0-34- generic N/A
DistroRelease: Ubuntu 17.10
Package: linux-generic 4.13.0.25.26
ProcVersionSign
Uname: Linux 4.8.0-34-generic x86_64
ApportVersion: 2.20.7-0ubuntu3.7
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/pcmC0D0p: misaki 1685 F...m pulseaudio
/dev/snd/
CurrentDesktop: GNOME-Flashback
Date: Sun Jan 21 00:17:16 2018
HibernationDevice: RESUME=
MachineType: ASUSTeK Computer Inc. N50Vn
ProcFB: 0 nouveaufb
ProcKernelCmdLine: BOOT_IMAGE=
RelatedPackageV
linux-
linux-
linux-firmware 1.169.1
SourcePackage: linux
UpgradeStatus: Upgraded to artful on 2018-01-09 (12 days ago)
WpaSupplicantLog:
dmi.bios.date: 03/05/2009 asset.tag: ATN123456789012 34567 asset.tag: ATN123456789012 34567 version: 1.0 MegatrendsInc. :bvr211: bd03/05/ 2009:svnASUSTeK ComputerInc. :pnN50Vn: pvr1.0: rvnASUSTeKCompu terInc. :rnN50Vn: rvr1.0: cvnASUSTeKCompu terInc. :ct10:cvr1. 0: version: 1.0
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 211
dmi.board.
dmi.board.name: N50Vn
dmi.board.vendor: ASUSTeK Computer Inc.
dmi.board.version: 1.0
dmi.chassis.
dmi.chassis.type: 10
dmi.chassis.vendor: ASUSTeK Computer Inc.
dmi.chassis.
dmi.modalias: dmi:bvnAmerican
dmi.product.name: N50Vn
dmi.product.
dmi.sys.vendor: ASUSTeK Computer Inc.