Bug 28078 - poor screen repaint peformance in Ubuntu Karmic using GM 45 chipset
Summary: poor screen repaint peformance in Ubuntu Karmic using GM 45 chipset
Alias: None
Product: DRI
Classification: Unclassified
Component: DRM/Intel (show other bugs)
Version: XOrg git
Hardware: x86 (IA32) Linux (All)
: medium major
Assignee: Jesse Barnes
QA Contact:
Depends on:
Reported: 2010-05-12 18:01 UTC by George
Modified: 2017-07-24 23:08 UTC (History)
0 users

See Also:
i915 platform:
i915 features:

Xorg.0.log file containing above cited DRM errors (109.14 KB, application/octet-stream)
2010-05-12 18:01 UTC, George
no flags Details

Description George 2010-05-12 18:01:00 UTC
Created attachment 35602 [details]
Xorg.0.log file containing above cited DRM errors


following the recommended bug report template, plz c below.

Bug description:

Screen repaint operations are extremely slow (e.g. minimizing a window takes seconds to complete). System monitor's CPU History shows one of the two CPU running 100% busy for periods up to 10 to 15 seconds. Using 'top', I determined that the 'X' process was consuming most of the CPU cycles. Usually I'm using an external Dell 1909 monitor connected to a Dell Inspiron 1545 laptop's VGA port. However, this problem will also occur without the external monitor attached.

The problem appeared after upgrading from Ubuntu Jaunty to Karmic. Looking at "Xorg.0.log" I notice the following errors that might be relevant:

(EE) intel(0): [drm] Failed to open DRM device for : No such file or directory
(EE) intel(0): Failed to become DRM master.
(EE) intel(0): Failed to initialize kernel memory manager

System environment:
-- chipset: Intel GM45
-- system architecture: i686, dual CPU
-- xf86-video-intel: 2.9.0
-- xserver: 1.6.4
-- mesa: not sure
-- libdrm2: 2.4.14-1ubuntu1
-- libdrm-intel1: 2.4.14-1
-- kernel: 2.6.28-18
-- Linux distribution: Ubuntu 9.10 Karmic
-- Machine or mobo model: Dell Inspiron 1545n laptop with external Dell 1909W monitor
-- Display connector: VGA
Comment 1 George 2010-05-14 10:12:39 UTC
I have discovered the cause of this problem and its solution. I investigated the DRM related errors logged in Xorg.0.log. I also noticed that I was booted under Linux 2.6.28-21 yet there was a Linux 2.6.31-21 available under /boot. In fact, the GRUB boot menu did not list the 2,6.31-21 image as a boot option. Looking further, I noticed that boot menu screen was generated by GRUB2 (i.e. v1.97) yet my grub-install -v said that GRUB v0.97 was installed!

I used Synaptics package manager to install the grub2-pc package and remove the GRUB v1 tools. I did a restart, the system booted without a boot menu screen directly into Linux 2.6.31-21. The video repaint performance problem disappeared ;o)

The above solution does not explain why the automated upgrade from Ubuntu Jaunty to Karmic did not correctly install the GRUB v2 tools in place of GRUB v1 tools. The upgrade did adjust the GRUB v1 menu.lst file to chainload the GRUB v2 menu.

Another remaining open question is why did the Linux 2.6.28 work at all after the DRM errors? Perhaps one way to bullet proof against this class of problems is verify the module and kernel version levels are compatible at start up time and if needed then log a diagnostic in Xorg.0.log?

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