Kernel lockup/crash while using desktop switcher in unity

[Bryce Harrington]

I was trying to diagnose a bug with workspaces and moving around from desktop to desktop when the screen suddenly froze (no corruption, just stopped updating). Could not vt switch, but could ssh in and file this bug report from the console. Looking at dmesg appears to be a drm fault.

[ 1332.008002] INFO: rcu_sched detected stall on CPU 0 (t=15000 jiffies)
[ 1332.008003] Pid: 2574, comm: Xorg Not tainted 3.2.0-4-generic-pae #10-Ubuntu
[ 1332.008003] Call Trace:
[ 1332.008003] [<c158f18c>] ? printk+0x2d/0x2f
[ 1332.008003] [<c10c50e3>] check_cpu_stall.isra.36+0x93/0xe0
[ 1332.008003] [<c10c515a>] __rcu_pending+0x2a/0x140
[ 1332.008003] [<c10c550c>] rcu_check_callbacks+0x6c/0x1d0
[ 1332.008003] [<c1069c0b>] update_process_times+0x3b/0x70
[ 1332.008003] [<c108b03e>] tick_sched_timer+0x5e/0xc0
[ 1332.008003] [<c107cf90>] ? __remove_hrtimer+0x40/0xa0
[ 1332.008003] [<c107d6bf>] __run_hrtimer+0x6f/0x1b0
[ 1332.008003] [<c108afe0>] ? tick_nohz_handler+0x100/0x100
[ 1332.008003] [<c107e035>] hrtimer_interrupt+0xe5/0x260
[ 1332.008003] [<c15ac3a4>] smp_apic_timer_interrupt+0x54/0x88
[ 1332.008003] [<c15a50e9>] apic_timer_interrupt+0x31/0x38
[ 1332.008003] [<c15a00e0>] ? get_ranges+0xcb/0x10e
[ 1332.008003] [<f8a7d0f6>] ? i915_gem_get_aperture_ioctl+0x66/0xb0 [i915]
[ 1332.008003] [<f8974f28>] drm_ioctl+0x378/0x480 [drm]
[ 1332.008003] [<f8a7d090>] ? i915_gem_init_ioctl+0x80/0x80 [i915]
[ 1332.008003] [<c117b278>] ? fsnotify+0x198/0x250
[ 1332.008003] [<f8974bb0>] ? drm_copy_field+0x80/0x80 [drm]
[ 1332.008003] [<c1154139>] do_vfs_ioctl+0x79/0x2d0
[ 1332.008003] [<c1143830>] ? wait_on_retry_sync_kiocb+0x50/0x50
[ 1332.008003] [<c11543ff>] sys_ioctl+0x6f/0x80
[ 1332.008003] [<c15abb9f>] sysenter_do_call+0x12/0x28

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: xserver-xorg-video-intel 2:2.15.901-1ubuntu4
ProcVersionSignature: Ubuntu 3.2.0-4.10-generic-pae 3.2.0-rc5
Uname: Linux 3.2.0-4-generic-pae i686
ApportVersion: 1.90-0ubuntu1
Architecture: i386
CompizPlugins: [core,bailer,detection,composite,opengl,decor,imgpng,gnomecompat,regex,place,snap,vpswitch,mousepoll,grid,compiztoolbox,animation,move,session,resize,unitymtgrabhandles,workarounds,wall,expo,fade,ezoom,scale,unityshell]
Date: Thu Dec 15 20:47:24 2011
DistUpgraded: Fresh install
DistroCodename: precise
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes, whatever it takes to get this fixed in Ubuntu
GraphicsCard:
 Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller [8086:2a42] (rev 07) (prog-if 00 [VGA controller])
   Subsystem: Fujitsu Limited. Device [10cf:1458]
   Subsystem: Fujitsu Limited. Device [10cf:1458]
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha i386 (20111121)
MachineType: FUJITSU LifeBook T4410
PccardctlIdent:
 Socket 0:
   no product info available
PccardctlStatus:
 Socket 0:
   no card
ProcEnviron:
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-4-generic-pae root=UUID=74b73169-6ac4-4698-bb5e-1f9b21250507 ro quiet splash vt.handoff=7
SourcePackage: xserver-xorg-video-intel
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 09/30/2009
dmi.bios.vendor: FUJITSU // Phoenix Technologies Ltd.
dmi.bios.version: Version 1.05
dmi.board.name: FJNB206
dmi.board.vendor: FUJITSU
dmi.chassis.type: 10
dmi.chassis.vendor: A40R8CE708EA1001
dmi.modalias: dmi:bvnFUJITSU//PhoenixTechnologiesLtd.:bvrVersion1.05:bd09/30/2009:svnFUJITSU:pnLifeBookT4410:pvr:rvnFUJITSU:rnFJNB206:rvr:cvnA40R8CE708EA1001:ct10:cvr:
dmi.product.name: LifeBook T4410
dmi.sys.vendor: FUJITSU
version.compiz: compiz 1:0.9.6+bzr20110929-0ubuntu8
version.libdrm2: libdrm2 2.4.27-1ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 7.11-0ubuntu4
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 7.11-0ubuntu4
version.xserver-xorg-core: xserver-xorg-core 2:1.10.4-1ubuntu6
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.6.0-1ubuntu13
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.99~git20110811.g93fc084-0ubuntu1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.15.901-1ubuntu4
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20111201+b5534a1-1

[Brad Figg (brad-figg)]

Thank you for taking the time to file a bug report on this issue.

However, given the number of bugs that the Kernel Team receives during any development cycle it is impossible for us to review them all. Therefore, we occasionally resort to using automated bots to request further testing. This is such a request.

We have noted that there is a newer version of the development kernel than the one you last tested when this issue was found. Please test again with the newer kernel and indicate in the bug if this issue still exists or not.

If the bug still exists, change the bug status from Incomplete to Confirmed. If the bug no longer exists, change the bug status from Incomplete to Fix Released.

If you want this bot to quit automatically requesting kernel tests, add a tag named: bot-stop-nagging.

 Thank you for your help, we really do appreciate it.

[Hernando Torque (htorque)]

Maybe dupe of bug 903654?

[Bryce Harrington (bryce)]

On Fri, Dec 16, 2011 at 10:38:51AM -0000, Hernando Torque wrote:
> Maybe dupe of bug 903654?

Maybe, but hard to say since there isn't a stacktrace given there.

Sarvatt references upstream bug
http://www.spinics.net/lists/dri-devel/msg17211.html, which has a
stacktrace that does not appear to be the same stacktrace I got. Also,
they mentioned that fault occurs 1x/hr, whereas in my case the crash
occurred only one time over several dozen hour's use.

So, while I agree these sound suspiciously similar, I don't think there
is solid enough evidence to prove they're dupes yet.

[Bryce Harrington (bryce)]

After updating to 3.2.0-6.12 I'm not seeing this bug when trying to reproduce it via workspace switching.