ubuntu-x-swat team mailing list archive

[TJ <567696@xxxxxxxxxxxxxxxxxx>]

** Description changed:

- Whilst running an update-manager session for Lucid 10.04 i386 the
- update-manager appeared to 'freeze' midway. The rest of the Gnome
- interface was similarly unresponsive and the mouse cursor displays the
- animated 'busy' circle (but it wasn't being animated).
+ Symptoms: Jerky mouse with no further response from application windows,
+ keyboard input ignored, CPU running at 100%, hard reboot required.
  
- The system has been working correctly in all other respects so far as I
- have been able to tell. It is a dual-CPU Asus A7M266D motherboard with
- two Athlon MP 2000 CPUs.
+ The message "[mi] EQ overflowing. The server is probably stuck in an
+ infinite loop" appearing in the X server's log (/var/log/Xorg.0.log) is
+ a symptom of a number of other bugs. It is *not* a bug in itself.
  
- Connecting over ssh I found an error in /var/log/Xorg.0.log:
+ *** Unless the backtrace in Xorg.0.log is precisely the same as this
+ one, please POST A NEW BUG REPORT with the backtrace ***
+ 
+ Usually all attempts to regain control of the system locally fail - no
+ switching to the other virtual terminals, no ability to kill the
+ Xserver. Remote connections via SSH usually work but the only way to
+ return the system to a usable state is to force a restart (sudo shutdown
+ -r now).
+ 
+ The symptom has been manifesting itself since 2008 (kernel 2.6.25) at
+ least on many different distributions. It is related to the use of DRI
+ and accelerated 3D graphics.
+ 
+ Turning off Desktop Effects (Compiz) can reduce the incidents but other
+ applications that use OpenGL and EXA (such as Firefox, or games like
+ Unreal Tournament) can trigger it easily.
+ 
+ There is a suggestion that using:
+ 
+ export SDL_VIDEO_X11_DGAMOUSE=0
+ 
+ prior to launching SDL applications will avoid the issue but this
+ doesn't help Firefox.
+ 
+ 
+ Other reports:
+ 
+ RedHat https://bugzilla.redhat.com/show_bug.cgi?id=465884
+ 
+ A clear explanation of the report is found in a mailing-list post by
+ Adam Jackson @ RedHat: http://marc.info/?l=fedora-devel-
+ list&m=124101535025331&w=2
+ 
+ " "EQ overflowing" is not a bug, dang it.  It's a symptom.
+ 
+ Input events are handled in two places in X.  A signal handler reads the
+ events from the kernel, updates the cursor position, and adds the event
+ to the queue; and then the main loop drains the event queue, sending
+ events to clients and possibly updating the cursor image (say, if it
+ changes from an arrow to a text bar).  Since you can't malloc from
+ signal handlers, the event queue is some fixed (but large) size.
+ 
+ If you run out of space in the event queue, it's because the server is
+ stuck somewhere away from the main loop.  But that's not any one
+ specific place, that's the entire rest of the X server.  You could be
+ waiting for the hardware to go idle.  You could be waiting to acquire
+ the DRI lock (in DRI1).  You could be trying to do some kernel request
+ that the kernel is taking its sweet time to get around to.  _Anything_.
+ So "EQ overflowing" is not any one particular bug, it's a symptom of
+ many different bugs."
+ 
+ 
+ Extract from /var/log/Xorg.0.log:
  
  Unhandled monitor type 0
  disable primary dac
  enable primary dac
  [mi] EQ overflowing. The server is probably stuck in an infinite loop.
  
  Backtrace:
  0: /usr/bin/X (xorg_backtrace+0x3b) [0x80e937b]
  1: /usr/bin/X (mieqEnqueue+0x1ab) [0x80e8b6b]
  2: /usr/bin/X (xf86PostMotionEventP+0xd2) [0x80c2d02]
  3: /usr/lib/xorg/modules/input/evdev_drv.so (0x5a6000+0x48a1) [0x5aa8a1]
  4: /usr/lib/xorg/modules/input/evdev_drv.so (0x5a6000+0x4b96) [0x5aab96]
  5: /usr/bin/X (0x8048000+0x6d5bf) [0x80b55bf]
  6: /usr/bin/X (0x8048000+0x122774) [0x816a774]
  7: (vdso) (__kernel_sigreturn+0x0) [0x862400]
  8: /usr/lib/xorg/modules/drivers/radeon_drv.so (0x4a5000+0xe4c5) [0x4b34c5]
  9: /usr/lib/xorg/modules/drivers/radeon_drv.so (0x4a5000+0xe8e9) [0x4b38e9]
  10: /usr/lib/xorg/modules/drivers/radeon_drv.so (0x4a5000+0xa7e41) [0x54ce41]
  11: /usr/lib/xorg/modules/libexa.so (0xe5f000+0xc78d) [0xe6b78d]
  12: /usr/lib/xorg/modules/libexa.so (0xe5f000+0xd498) [0xe6c498]
  13: /usr/bin/X (0x8048000+0xd892b) [0x812092b]
  14: /usr/bin/X (CompositePicture+0x298) [0x8113c58]
  15: /usr/lib/xorg/modules/libexa.so (0xe5f000+0xc224) [0xe6b224]
  16: /usr/bin/X (CompositeTrapezoids+0x9e) [0x811392e]
  17: /usr/bin/X (0x8048000+0xd4563) [0x811c563]
  18: /usr/bin/X (0x8048000+0xcea03) [0x8116a03]
  19: /usr/bin/X (0x8048000+0x2a477) [0x8072477]
  20: /usr/bin/X (0x8048000+0x1ed7a) [0x8066d7a]
  21: /lib/tls/i686/cmov/libc.so.6 (__libc_start_main+0xe6) [0x1c8bd6]
  22: /usr/bin/X (0x8048000+0x1e961) [0x8066961]

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https://bugs.launchpad.net/bugs/567696

Title:
  [mi] EQ overflowing. The server is probably stuck in an infinite loop

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