[i915] [regression] Xorg excessive use of CPU (after update from lucid to precise)

[Rolf Leggewie]

I updated from lucid to precise about three weeks ago, hoping that the major wrinkles would have been ironed out by now. Unfortuantely, that isn't so. One very major complication for me is that over time X will use up vast amounts of CPU cycles, usually reaching 100% on one core after about 24 hours of uptime. The computer is an ASUS 1001P with intel i915 graphics.

Obviously, the whole system becomes very sluggish, fans running on high speed when X grabs a full core for itself. After closing all programs, X release the grip somewhat but keeps oscillating between 20 and 60% load on a single core with essentially no other programs running.

I am aware this may very well be a bug in another package and not in X itself. So far I can't pinpoint anything, except that it appears that Firefox with many tabs open seems to be an accelerating factor to deteriorate the situation. I carried over the Firefox package from lucid to precise and updated from version 15 to 17 only yesterday. I pin Firefox because the recent release cycle is exposing me to too many regressions. I hoped the problem with X might go away by going to 17 now but that's not the case. Since version 15 acted fine in lucid and a precise installation with the same package misbehaved this seems to indicate that Firefox might not be the culprit (although I wouldn't yet rule it out completely).

The problem occurs with both the lucid, precise and mainline kernel, although I felt it might have taken longer with the lucid kernel.

Since it takes a while for the regression to rear its head, I'm afraid I can't test with a live CD or a later relase, I need my computer. I'm willing to do gdb or git bisection work, but I'm somewhat inexperienced how to get X to run inside gdb. Some guidance would be appreciated.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: xserver-xorg-video-intel 2:2.17.0-1ubuntu4.2
ProcVersionSignature: Ubuntu 3.2.0-34.53-generic 3.2.33
Uname: Linux 3.2.0-34-generic i686
.tmp.unity.support.test.0:

ApportVersion: 2.0.1-0ubuntu15
Architecture: i386
CompizPlugins: [core,composite,opengl,compiztoolbox,decor,mousepoll,screenshot,regex,move,snap,gnomecompat,wall,vpswitch,place,session,resize,grid,animation,imgpng,expo,ezoom,workarounds,fade,scale,unityshell]
CompositorRunning: None
Date: Fri Dec 7 02:57:22 2012
DistUpgraded: 2012-11-17 18:58:48,482 DEBUG failed to SystemUnLock() (E:Not locked)
DistroCodename: precise
DistroVariant: ubuntu
EcryptfsInUse: Yes
ExtraDebuggingInterest: Yes, even including gdb or git bisection work if needed
GraphicsCard:
 Intel Corporation N10 Family Integrated Graphics Controller [8086:a011] (prog-if 00 [VGA controller])
   Subsystem: ASUSTeK Computer Inc. Device [1043:83ac]
   Subsystem: ASUSTeK Computer Inc. Device [1043:83ac]
MachineType: ASUSTeK Computer INC. 1001P
MarkForUpload: True
ProcEnviron:
 TERM=xterm
 PATH=(custom, user)
 LANG=de_DE.UTF-8
 LC_MESSAGES=C
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.2.0-34-generic root=/dev/mapper/hostname-root ro quiet splash acpi_osi=Linux backlight=vendor i915.i915_enable_fbc=1 drm.vblankoffdelay=1
SourcePackage: xserver-xorg-video-intel
UpgradeStatus: Upgraded to precise on 2012-11-17 (19 days ago)
dmi.bios.date: 06/23/2010
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 1202
dmi.board.asset.tag: To Be Filled By O.E.M.
dmi.board.name: 1005P
dmi.board.vendor: ASUSTeK Computer INC.
dmi.board.version: x.xx
dmi.chassis.asset.tag: 0x00000000
dmi.chassis.type: 10
dmi.chassis.vendor: ASUSTeK Computer INC.
dmi.chassis.version: x.x
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1202:bd06/23/2010:svnASUSTeKComputerINC.:pn1001P:pvrx.x:rvnASUSTeKComputerINC.:rn1005P:rvrx.xx:cvnASUSTeKComputerINC.:ct10:cvrx.x:
dmi.product.name: 1001P
dmi.product.version: x.x
dmi.sys.vendor: ASUSTeK Computer INC.
version.compiz: compiz 1:0.9.7.8-0ubuntu1.4
version.libdrm2: libdrm2 2.4.32-1ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 8.0.4-0ubuntu0.2
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 8.0.4-0ubuntu0.2
version.xserver-xorg-core: xserver-xorg-core 2:1.11.4-0ubuntu10.8
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.7.0-0ubuntu1.2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.99~git20111219.aacbd629-0ubuntu2
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.17.0-1ubuntu4.2
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau N/A

[Rolf Leggewie (r0lf)]

http://www.x.org/wiki/Development/Documentation/ServerDebugging has some information how to use gdb with X but I am not sure this is relevant since Xorg isn't crashing. What's needed is to find out what X is doing when it's running at 100% CPU.

[Rolf Leggewie (r0lf)]

https://wiki.ubuntu.com/X/Backtracing
http://wiki.debian.org/XStrikeForce/XserverDebugging
https://wiki.ubuntu.com/X/Troubleshooting/HighCPU

$ glxinfo | grep render
direct rendering: Yes
OpenGL renderer string: Mesa DRI Intel(R) IGD x86/MMX/SSE2
$ egrep '(loop|EE)' /var/log/Xorg.0.log
 (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
[ 34.076] (II) Loading extension MIT-SCREEN-SAVER

[Rolf Leggewie (r0lf)]

unfortunately, the problem occurs with the mainline kernel as well

[Chris Wilson (ickle)]

Can you repeat your testing with raring? I'm sure whether you have a 2D performance issue or if you are trying to use OpenGL.

[bugbot (bugbot)]

We're closing this bug since there has not been a response from the original reporter. However, the issue still exists please feel free to reopen with the requested information. If you're not the original reporter, we'd prefer you file a new bug report.

Some tips:

  * Report X.org bugs via the command: `ubuntu-bug xorg`

  * Test against the latest development Ubuntu. http://cdimage.ubuntu.com/daily-live/
    Bugs marked as affecting the development version tend to get priority attention.

  * The `xdiagnose` utility has functionality for enabling debugging and
    analyzing a few common X problems.

  * Tag your bugs with the Ubuntu versions you have reproduced the issue in.

  * See https://wiki.ubuntu.com/X/Reporting for tips on writing good bug reports.