xorg takes 100% cpu -- but only on first login

[Pauli Virtanen]

Binary package hint: xorg

On Ubuntu Karmic & Nvidia's non-free drivers: after logging in, Xorg takes 100% CPU. No application seems to be redrawing anything (no firefox. Xorg is also the only large CPU user). Apart from the large CPU usage, everything seems to be working normally.

The curious thing is that the situation is fixed by logging out (back to gdm), and then logging in again. Then, Xorg's CPU usage is back to normal.

ProblemType: Bug
Architecture: i386
Date: Sun Sep 27 14:41:24 2009
DistroRelease: Ubuntu 9.10
MachineType: System Manufacturer System Name
NonfreeKernelModules: nvidia
Package: xorg 1:7.4+3ubuntu5
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.31-11-generic root=UUID=1333b097-1cf5-44a3-bf1b-13c71021ecf7 ro quiet splash
ProcEnviron:
 LANGUAGE=fi_FI.UTF-8
 LC_COLLATE=C
 PATH=(custom, user)
 LANG=fi_FI.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-11.36-generic
RelatedPackageVersions:
 xserver-xorg 1:7.4+3ubuntu5
 libgl1-mesa-glx 7.6.0~git20090817.7c422387-0ubuntu5
 libdrm2 2.4.13-1ubuntu1
 xserver-xorg-video-intel 2:2.8.1-1ubuntu2
 xserver-xorg-video-ati 1:6.12.99+git20090825.fc74e119-0ubuntu2
SourcePackage: xorg
Uname: Linux 2.6.31-11-generic i686
dmi.bios.date: 04/08/2004
dmi.bios.vendor: Award Software, Inc.
dmi.bios.version: ASUS A7V600-X ACPI BIOS Revision 1003
dmi.board.name: A7V600-X
dmi.board.vendor: ASUSTeK Computer INC.
dmi.board.version: REV 1.xx
dmi.chassis.asset.tag: Asset-1234567890
dmi.chassis.type: 7
dmi.chassis.vendor: Chassis Manufacture
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnAwardSoftware,Inc.:bvrASUSA7V600-XACPIBIOSRevision1003:bd04/08/2004:svnSystemManufacturer:pnSystemName:pvrSystemVersion:rvnASUSTeKComputerINC.:rnA7V600-X:rvrREV1.xx:cvnChassisManufacture:ct7:cvrChassisVersion:
dmi.product.name: System Name
dmi.product.version: System Version
dmi.sys.vendor: System Manufacturer
fglrx: Not loaded
system:
 distro: Ubuntu
 architecture: i686kernel: 2.6.31-11-generic

[Pauli Virtanen (pauli-virtanen)]

More information: when Xorg is consuming CPU on the first login, when I switch to another VT, the VT switches immediately back to X. I also cannot use the "Switch to another user" feature. Like so:

1. Ctrl+Alt+SysRQ+R (release keyboard)
2. Alt+F1 (switch VT)
3. In a fraction of a second, VT switches back to X. VT1 only flashes by.

This does not happen on the second login: there, VT stays at VT1 and does not switch back by itself.
Is it possible that part of Xorg is running in some busy-loop, constantly switching the VT?

I cannot easily attach a gdb to Xorg due to the VT problem. I may try setting up some ssh setup later on.

[Thomas Bechtold (toabctl)]

with a ThinkPad X200s (intel graphic chip), i have the same problem.

[Christoph Klaffl (z3r0c00l)]

I have an old Intel GM855 Graphic Adapter, same problem