many crashes of X server, what should I investigate?

[Frédéric Bron]

>> I have many crashes of the X server:
>> - freezing when switching between user
>> - freezing when starting a session
>
> What kind of machine are you running F17 on?  What processor?  How much
> memory?  What video card?

I have a laptop with:
Processor Intel® Core I7 - I7-2760QM - 2.40 GHz / 3.50 GHz (Max Turbo
Freq.) - (Quad-core mobile - Socket FCPGA988 - 6 Mo cache L2 - 32 nm -
45 W - 64-bitsVirtualisation - Hyperthreading (8 threads) - integrated
HD Graphics 3000)
LED screen 17.3" Full-HD 1920 x 1080 TFT
16 Go SO-DIMM RAM DDR-3 / 1333 MHz (4 x 4 Go)
Video controler nVidia GeForce GTX 560M with 1.5 Go dedicated VRAM
DDR-5 (Support PCIe x16, DirectX 11, nVidia PhysX, HDMI 1.4, HDCP,
GeForce CUDA)
Chipset Intel HM67 2nd generation
Technology PCI-Express
Main bus (FSB) 1333 MHz
Technology Intel® for processors Intel® Core I7 and Core I7 Extreme
Edition Sandy Bridge 2nd generation (64-bits mobile)
Support PCI-Express x16 et DirectX 11
Graphical accelerator 2D/3D at 128 bits, decoding MPEG I & II, DVD-playback

I have installed F17 64 bits: Linux mymachine 3.6.10-2.fc17.x86_64 #1
SMP Tue Dec 11 18:07:34 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux

>  Do you have it overclocked?

No

> Are you using the
> default video driver that comes with F17 or did you install the proprietary
> video driver issued by the video chip manufacturer?

I am using the nvidia proprietary driver (I used kmod-nvidia and
switched to akmod-nvidia recently because the 3.6.10 driver did not
come but this did not change anything).
I have read a thread that reports the same issue on gdm bug tracker
and someone tried both nvidia and nouveau with no difference but I
have not done it myself.

> Do you have another machine networked to this machine?  If you do you can
> open a terminal session on this machine using ssh.  You might find some
> clues in dmesg

I will try that. I have just tested that I can connect by ssh and it works fine.
Halas, I could not reproduce the freeze but I got only a small freeze
(30 sec.) and dmesg during that freeze gave:

[62645.848785] SELinux: initialized (dev fuse, type fuse), uses genfs_contexts
[62906.805823] SELinux: initialized (dev fuse, type fuse), uses genfs_contexts
[62965.449065] nepomukservices[26117]: segfault at 0 ip
(null) sp 00007fff6096e428 error 14 in nepomukservicestub[400000+7000]
[63022.645742] NVRM: GPU at 0000:01:00: GPU-a26ca184-dbb8-cb76-a255-3c1db789ce86
[63022.645758] NVRM: Xid (0000:01:00): 31, Ch 00000002, engmask
00000101, intr 10000000
[63023.160005] NVRM: Xid (0000:01:00): 8, Channel 00000004

I see also that after trying to open lots of sessions and close them,
my 16 Gb memory is full and I had difficulties openning a new terminal
because it said "bash fork retry no child processes". I do not know if
it is linked but I read somewhere that when X freezes, it may be due
to memory leaks...

I will come back later with more info if a new crash happen.

Thanks,

Frédéric