Bug#585663: xorg: i915 and DRI leak memory

[Juha Jäykkä <juhaj@iki.fi>]

Package: xorg
Version: 1:7.5+6
Severity: important


X with xserver-xorg-video-intel is no longer usable: is causes memory corruption
which can only be solved by restarting X every week or so.

A little bit of googling suggests this is related to DRI corrupting kernel memory,
so I am not sure if this is kernel or X bug, please retarget as necessary.

Symptoms: SUnreclaim slab increases by about 1 MB per minute, yielding about 1 GB
of SUnreclaim within two weeks. This can be slowed down by not doing anything or
speeded up by opening windows, moving them around, causing a program to draw stuff
on screen etc. Basically any use of X increases the rate of memory corruption while
just letting it idle (without a screensaver!) slows it down. Of course, slowing
memory corruption speed down by doing nothing is not quite acceptable - if I did
no want to do anything with X, I would not start X in the first place.

Curiously, setting "DRI" and "DRI2" to "False" and "NoAccel" to "True" do not seem
to disable direct rendering: glxinfo still says; "direct rendering: Yes". What else
do I need to turn off to make X usable again?

Here are the values of the relevant parts on /proc/meminfo right after logging off X
but not yet shutting down kdm (i.e. X is still running) and immediately after 
shutting down kdm (and therefore X, too):

Before:
MemFree:          390412 kB
Buffers:               0 kB
Cached:           442828 kB
SwapCached:        52508 kB
Active:           182880 kB
Inactive:         405552 kB
Active(anon):      88712 kB
Inactive(anon):   110184 kB
Active(file):      94168 kB
Inactive(file):   295368 kB
AnonPages:        101876 kB
Mapped:            30536 kB
Slab:             976616 kB
SReclaimable:      23784 kB
SUnreclaim:       952832 kB

After:
MemFree:         1460024 kB
Buffers:               0 kB
Cached:           395244 kB
SwapCached:        41652 kB
Active:           106172 kB
Inactive:         344176 kB
Active(anon):      11348 kB
Inactive(anon):    49228 kB
Active(file):      94824 kB
Inactive(file):   294948 kB
AnonPages:         21496 kB
Mapped:            11620 kB
Slab:              47056 kB
SReclaimable:      23716 kB
SUnreclaim:        23340 kB


The culprit is kmalloc-32 according to slabinfo. Unfortunately I forgot to
save its output. Its size was about 940MB anyway.

I will be happy to provide more info as soon as the slab grows again in a few days. :/

-Juha

P.S. I realise my xserver-xorg-video-intel is from experimental, but the older versions
have been even less usable: mostly crashing or completely freezing at random (see 
#575965 for example).


-- System Information:
Debian Release: squeeze/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (500, 'testing'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 2.6.34 (SMP w/2 CPU cores)
Locale: LANG=C, LC_CTYPE=C (charmap=UTF-8) (ignored: LC_ALL set to en_GB.UTF-8)
Shell: /bin/sh linked to /bin/bash

Versions of packages xorg depends on:
ii  konsole [x-terminal-emulator] 4:4.4.3-1  X terminal emulator for KDE 4
ii  libgl1-mesa-dri               7.7.1-2    A free implementation of the OpenG
ii  libgl1-mesa-glx [libgl1]      7.7.1-2    A free implementation of the OpenG
ii  libglu1-mesa                  7.7.1-2    The OpenGL utility library (GLU)
ii  lxterminal [x-terminal-emulat 0.1.7-1    desktop independent vte-based term
ii  rxvt-unicode [x-terminal-emul 9.07-2     RXVT-like terminal emulator with U
ii  x11-apps                      7.5+5      X applications
ii  x11-session-utils             7.5+1      X session utilities
ii  x11-utils                     7.5+3      X11 utilities
ii  x11-xfs-utils                 7.4+1      X font server utilities
ii  x11-xkb-utils                 7.5+2      X11 XKB utilities
ii  x11-xserver-utils             7.5+1      X server utilities
ii  xauth                         1:1.0.4-1  X authentication utility
ii  xfonts-100dpi                 1:1.0.1    100 dpi fonts for X
ii  xfonts-75dpi                  1:1.0.1    75 dpi fonts for X
ii  xfonts-base                   1:1.0.1    standard fonts for X
ii  xfonts-scalable               1:1.0.1-1  scalable fonts for X
ii  xfonts-utils                  1:7.5+2    X Window System font utility progr
ii  xinit                         1.2.0-1    X server initialisation tool
ii  xkb-data                      1.8-1      X Keyboard Extension (XKB) configu
ii  xorg-docs-core                1:1.5-1    Core documentation for the X.org X
ii  xserver-xorg                  1:7.5+6    the X.Org X server
ii  xterm [x-terminal-emulator]   258-1      X terminal emulator

xorg recommends no packages.

Versions of packages xorg suggests:
ii  xorg-docs                     1:1.5-1    Miscellaneous documentation for th

-- no debconf information