Bug#568421: X hangs after upgrade from 7.4 to 7.5

[Jonathan Nieder <jrnieder@gmail.com>]

Hi Adam,

Adam Majer wrote:

> Today I've done an upgrade that only touched,
[... list of core X packages snipped ...]
> Following this upgrade, X would hang either immediately after start or
> few seconds afterwards.
[...]
> INFO: task Xorg:3075 blocked for more than 120 seconds.
> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> Xorg          D 0000000000000000     0  3075   3060 0x00400000
>  ffff880100861e28 0000000000000082 0000000000000000 0000000000000008
>  0000000000000400 ffffffff81408094 000000000000f8a0 ffff880100861fd8
>  00000000000155c0 00000000000155c0 ffff88013bcbebd0 ffff88013fab3980
> Call Trace:
>  [<ffffffff812339b7>] vga_get+0x115/0x141
>  [<ffffffff8104f777>] ? default_wake_function+0x0/0x14
>  [<ffffffff81233a14>] ? vga_arb_write+0x31/0x449
>  [<ffffffff81233aa6>] vga_arb_write+0xc3/0x449
>  [<ffffffff8116bbe4>] ? security_file_permission+0x16/0x18
>  [<ffffffff81102538>] vfs_write+0xb0/0x10a
>  [<ffffffff81102660>] sys_write+0x4c/0x74
>  [<ffffffff81010db2>] system_call_fastpath+0x16/0x1b
>
> I use nvidia drivers. I have tried nv drivers with exactly same
> results.

Yeah, processes should not get stuck in the D state like that.
Questions:

 1. Is this still reproducible?  How do the latest squeeze and
    sid kernels behave?  (To test a sid kernel on a squeeze system,
    the only packages aside from linux-image-foo you should need from
    outside squeeze are linux-base and initramfs-tools.)

 2. Please try uninstalling or blacklisting the nvidia driver to
    make sure that is not the cause, and send full "dmesg" output
    from this happening if possible.

 3. Output from dmesg after running "echo t >/proc/sysrq-trigger"
    while in this state would also be useful.  (Or run
    "echo 1 >/proc/sys/kernel/sysrq" to disable the paranoid checks
    and press alt-sysrq + t while in that state.  See
    Documentation/sysrq.txt for details.)

 4. (I'm just curious:) Does the nouveau driver behave any
    differently?

Thanks for reporting, and sorry for the slow response.
Jonathan