High Xorg CPU usage (95-99%): Karmic x86-64, fglrx, ATI Mobility Radeon HD 2600

[dnyaga]

Binary package hint: xorg

I have Gateway M62 laptop (Intel Core 2 Duo T5750; ATI Mobility Radeon HD 2600 [RV630/M76], 4GB RAM). I upgraded from Jaunty about a week ago. My system is constantly updated, in sync with changes in the Karmic repository.

Xorg performance has been terrible. With fglrx (installed from the Ubuntu repos), Xorg sometimes pins down one core completely, for prolonged periods (95-100% CPU usage). The problem may or may not go away on reboot (unpredictable, indeterminate). When it is "behaving", the system is snappy and usable. I purged my fglrx (and all config files and all related packages) and reinstalled afresh from the Karmic repos. No change.

I do not run compositing on my desktop. I have a dual screen configuration (with an external 19 inch Acer monitor, see attached Xorg.conf files).

Now, fglrx is actually the good one this time round (surprisingly). When I _purged_ fglrx, I decided to run on the open source drivers for a while. Performance with the open source drivers is not merely bad - its goddamn awful. An example - It is impossible to run Netbeans or Eclipse and get any work done. Screen painting is so slow that there is a lag of up to 5 seconds between a click and a response. Dragging a small window (like Gnome terminal) is an ulcer inducing experience. This system is not performance, memory or load challenged.

Booting without an xorg.conf with the aim of running a non mirrored dual screen setup is presently not an option.

Other problems (not directly related to xorg) include the inability of gnome-display-properties and grandr to correctly set up the screen resolutions of both screens. These should (and probably, will) be reported as separate bugs, but I have mentioned them here for context.

I have attached:
(1) A screenshot of gnome-terminal (top) showing the load
(2) My present xorg.conf, generated by amdcccle
(3) The xorg.conf used with the -radeon driver)
(4) An Xorg.conf that previously worked well with fglrx (I keep /etc under version control), under Jaunty
(5) An Xorg.conf that previously worked well with the open source driver, under Jaunty

ProblemType: Bug
Architecture: amd64
Date: Fri Oct 2 11:05:10 2009
DistroRelease: Ubuntu 9.10
NonfreeKernelModules: fglrx
Package: xserver-xorg 1:7.4+3ubuntu5
ProcEnviron:
 SHELL=/bin/bash
 PATH=(custom, user)
 LANG=en_US.UTF-8
ProcVersionSignature: Ubuntu 2.6.31-11.36-generic
RelatedPackageVersions:
 xserver-xorg 1:7.4+3ubuntu5
 libgl1-mesa-glx 7.6.0~git20090817.7c422387-0ubuntu6
 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 x86_64
system:
 distro: Ubuntu
 architecture: x86_64kernel: 2.6.31-11-generic

[dnyaga (daniel-nyaga)]

Minimalist xorg.conf that "worked" with the open source drivers in terms of correct screen resolutions but had truly awful performance: My screens are a 1200x800 (laptop) screen and a 1366x768 external monitor.

Section "Screen"
 Identifier "Configured Screen Device"
 Device "Configured Video Device"
 SubSection "Display"
  Virtual 2646 800
 EndSubSection
EndSection

Section "Device"
 Identifier "Configured Video Device"
EndSection

[dnyaga (daniel-nyaga)]

With jaunty, I ran with this xorg.conf (which is nearly identical to the one above): Performance was good.

Section "Screen"
 Identifier "Configured Screen Device"
 Device "Configured Video Device"
 SubSection "Display"
  Virtual 2646 768
 EndSubSection
EndSection

Section "Device"
 Identifier "Configured Video Device"
EndSection

[dnyaga (daniel-nyaga)]

Added output of lspci -vvnn

[dnyaga (daniel-nyaga)]

Completely purged all fglrx and reinstalled/reconfigured core xorg components and the radeon driver as per the Ubuntu Wiki instructions:
  sudo /usr/share/ati/fglrx-uninstall.sh # (if it exists)
  sudo apt-get remove --purge fglrx*
  sudo apt-get remove --purge xserver-xorg-video-ati xserver-xorg-video-radeon
  sudo apt-get install xserver-xorg-video-ati
  sudo apt-get install --reinstall libgl1-mesa-glx libgl1-mesa-dri xserver-xorg-core
  sudo dpkg-reconfigure xserver-xorg

General 2D performance is OK. In particular, regular GTK (GNOME) and Qt (KDE) apps are responsive. CPU usage is normal (was always normal with -radeon, performance was the problem)

The most severely affected programs for me were the pure java ones (Netbeans being a particular pain point: Java 2D?) I am using the Sun Java 1.6 JVM, installed from the Ubuntu repos. I will code in Netbeans for a while to get a feel for the speed/responsiveness of the system with these drivers.

In all likelihood, this is not a valid xorg bug. But I will leave it for someone with more xorg knowledge and experience to close.

[Bryce Harrington (bryce)]

Thanks, yeah sounds weird, but usually X's CPU load is driven by stuff outside X, so perhaps you had a misbehaving client application.

[dnyaga (daniel-nyaga)]

Same issue keeps on popping up. 100% CPU usage immediately upon login (default desktop, no apps started). Logging out then back in "solves" the issue.

[dariusan (dariusan)]

I have same symptoms (high cpu load on xorg process) and use same workaround: logout and login -> cpu load of xorg back to normal, but i have intel gpu on first intel mac mini version

[dariusan (dariusan)]

Why is this bug set to invalid?

[Brian Takita (brian-takita)]

I also have similar symptoms.
Login, 50-60% CPU (I have 4 cores). Logout and Login again and Xorg is fine.