High CPU usage in Xorg with NVIDIA reverse prime external monitor
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
nvidia-graphics-drivers-470 (Ubuntu) |
Expired
|
Undecided
|
Unassigned | ||
xserver-xorg-video-amdgpu (Ubuntu) |
Expired
|
Undecided
|
Unassigned |
Bug Description
With my Legion Slim 7 in hybrid graphics mode (using amdgpu to drive the laptop display) and an external monitor connected via the nvidia card on a USB-C/HDMI connection, Xorg consistently uses around 40% CPU even with no apps running.
If I put the laptop in discrete graphics mode so the nvidia card drives both the laptop display and the external monitor Xorg uses close to 0% CPU, which is what I would expect it to be in hybrid mode.
ProblemType: Bug
DistroRelease: Ubuntu 21.10
Package: xserver-xorg-core 2:1.20.13-1ubuntu1
ProcVersionSign
Uname: Linux 5.13.0-16-generic x86_64
NonfreeKernelMo
.proc.driver.
.proc.driver.
.proc.driver.
.proc.driver.
.proc.driver.
.proc.driver.
.proc.driver.
NVRM version: NVIDIA UNIX x86_64 Kernel Module 470.63.01 Tue Aug 3 20:44:16 UTC 2021
GCC version: gcc version 11.2.0 (Ubuntu 11.2.0-5ubuntu1)
ApportVersion: 2.20.11-0ubuntu69
Architecture: amd64
CasperMD5CheckR
CompositorRunning: None
Date: Thu Sep 23 11:48:15 2021
DistUpgraded: Fresh install
DistroCodename: impish
DistroVariant: ubuntu
DkmsStatus:
nvidia, 470.63.01, 5.13.0-16-generic, x86_64: installed
nvidia, 470.63.01, 5.14.5-
nvidia, 470.63.01, 5.15.0-
ExtraDebuggingI
GraphicsCard:
NVIDIA Corporation GA106M [GeForce RTX 3060 Mobile / Max-Q] [10de:2560] (rev a1) (prog-if 00 [VGA controller])
Subsystem: Lenovo GA106M [GeForce RTX 3060 Mobile / Max-Q] [17aa:3801]
Advanced Micro Devices, Inc. [AMD/ATI] Cezanne [1002:1638] (rev c5) (prog-if 00 [VGA controller])
Subsystem: Lenovo Cezanne [17aa:380c]
InstallationDate: Installed on 2021-09-15 (8 days ago)
InstallationMedia: Ubuntu 21.10 "Impish Indri" - Alpha amd64 (20210910)
MachineType: LENOVO 82K8
ProcEnviron:
LANGUAGE=en_AU:en
TERM=xterm-
PATH=(custom, no user)
LANG=en_AU.UTF-8
SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=
SourcePackage: xorg-server
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 08/02/2021
dmi.bios.release: 1.27
dmi.bios.vendor: LENOVO
dmi.bios.version: HACN27WW
dmi.board.
dmi.board.name: LNVNB161216
dmi.board.vendor: LENOVO
dmi.board.version: SDK0J40697WIN
dmi.chassis.
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.
dmi.ec.
dmi.modalias: dmi:bvnLENOVO:
dmi.product.family: Legion S7 15ACH6
dmi.product.name: 82K8
dmi.product.sku: LENOVO_
dmi.product.
dmi.sys.vendor: LENOVO
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.107-1
version.
version.
version.
version.
version.
version.
version.
version.
High CPU usage has always been a problem for the Nvidia driver. Although high CPU when no apps are running is new... Do you have any non-Ubuntu GNOME extensions running that might be updating the screen in ways you're not noticing? Xorg itself does idle to zero CPU very well so *something* external is probably triggering it.