Bug 40541 - unable to handle kernel NULL pointer dereference at (null)
Summary: unable to handle kernel NULL pointer dereference at (null)
Status: RESOLVED FIXED
Alias: None
Product: xorg
Classification: Unclassified
Component: Driver/nouveau (show other bugs)
Version: 7.4 (2008.09)
Hardware: x86-64 (AMD64) Linux (All)
: medium normal
Assignee: Nouveau Project
QA Contact: Xorg Project Team
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2011-09-01 03:03 UTC by bugs.freedesktop.org
Modified: 2012-01-31 11:56 UTC (History)
0 users

See Also:
i915 platform:
i915 features:

Attachments
Important parts of my logs. (27.00 KB, text/plain)
2011-09-01 03:03 UTC, bugs.freedesktop.org 		no flags Details
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Description bugs.freedesktop.org 2011-09-01 03:03:18 UTC 
Created attachment 50801 [details]
Important parts of my logs.

I am getting the attached Errors since I am using kwin 4.7.0 with OpenGL-ES.

I am not sure if the following is related: When I am changing window sizes several times my memory gets filled up. The memory is not released by restarting kwin or X. When I filled my memory by doing this, I do not have to wait long for the attached Error, but I do not know what triggers it exactly.

Occasionally, I also have thousands of messages of the following form in my logs:

Aug 08 18:06:09 [kernel] [ 3810.714471] [TTM] Failed to find memory space for buffer 0xffff8800bc392000 eviction.
Aug 08 18:06:09 [kernel] [ 3810.714476] [TTM] No space for ffff8800bc392000 (96 pages, 384K, 0M)
Aug 08 18:06:09 [kernel] [ 3810.714479] [TTM]   placement[0]=0x00070002 (1)
Aug 08 18:06:09 [kernel] [ 3810.714480] [TTM]     has_type: 1
Aug 08 18:06:09 [kernel] [ 3810.714482] [TTM]     use_type: 1
Aug 08 18:06:09 [kernel] [ 3810.714484] [TTM]     flags: 0x0000000A
Aug 08 18:06:09 [kernel] [ 3810.714485] [TTM]     gpu_offset: 0x00000000
Aug 08 18:06:09 [kernel] [ 3810.714487] [TTM]     size: 131072
Aug 08 18:06:09 [kernel] [ 3810.714489] [TTM]     available_caching: 0x00070000
Aug 08 18:06:09 [kernel] [ 3810.714491] [TTM]     default_caching: 0x00010000

This is the reason, why I did not upload full logs (all in all 40MB). Nevertheless, I can upload more logs if you wish so.

As you can see in the logs, I have this problem since several kernel versions.

My graphics card: GeForce 8600 GT

Some version information (only applicable for the last logged crash):

sys-kernel/gentoo-sources-3.0.1
x11-base/xorg-x11-7.4-r1
x11-drivers/xf86-video-nouveau-0.0.16_pre20110801
x11-libs/libdrm-2.4.26
media-libs/mesa-7.11
Comment 1 Marcin Slusarz 2011-09-01 08:45:16 UTC 
NULL pointer dereference in nv50_vm_map_sg was fixed in 3.1-rc4 (commits 8d3bb23609d4ae22803a15d232289fc09a7b61c4 and eac2095398668f989a3dd8d00be1b87850d78c01)

I'm not sure about the other errors. It looks like there is a VRAM leak somewhere. Can you test Nouveau Linux tree (*), with kmemleak enabled (if possible)?

(*) http://nouveau.freedesktop.org/wiki/InstallDRM
Comment 2 bugs.freedesktop.org 2012-01-31 11:56:16 UTC 
Yes, a kernel update fixed the NULL pointer dereference for me.

I do not experience the memory problem any more since I use kwin 4.8.0.

I still can not explain why killing kwin/X did not release the occupied memory, but since I do not experience problems any more and I can not give more detail, I mark this bug as resolved.

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