** Description changed:
[Problem]
Starting around 4/3, when mesa was upgraded from 7.3 to 7.4, several i965
users started noticing X freeze after several hours of use, triggered by
application usage especially noticeable with (but not unique to) compiz enabled.
+
+ [Impact]
+ The freeze bug affects a subset of i965 based systems, most particularly
those using compiz. Exact numbers cannot be determined, but may be as high as
25-50% based on rough estimates.
+
+ The problem is severe: An unpredictable lockup of the system that
+ requires a power cycle to recover from. For some users it comes on
+ within minutes, while for others it comes after a few hours of use.
+
+ [How Addressed in Development Version]
+ For now, the patch being proposed for Jaunty has been uploaded to Karmic.
+
+ Longer term, we plan to move from EXA to UXA once the latter is stable
+ enough. It has been found that while UXA exhibits other kinds of
+ freezes, we've not yet been able to reproduce this particular freeze
+ there.
+
+ [Patch for Jaunty]
+ A low-risk workaround that has proven effective at eliminating freezes, or at
least greatly reducing their frequency, is to increase the Virtual framebuffer
size. Some users do this locally as a matter of course to gain dual-head
support, so this setting has received extremely widespread testing already.
+
+ The patch for Jaunty causes the Virtual size to be set to 2048x2048 if
+ it is not otherwise specified. Users can still override this with their
+ own settings, larger or smaller, as desired.
+
+ A side effect of this patch is that it also will make projector usage
+ somewhat easier for this hardware, because it will enable X to recognize
+ higher resolutions available from the external monitor than were
+ available on initial boot.
+
+ [Test Case]
+
+ [Regression Potential]
[Suspects]
Omitting obviously trivial, unrelated changes, here are what changed in
several suspect packages in the timeframe in question:
* intel driver:
4/01: 118_drop_legacy3d.patch: Removed Legacy3D
4/03: 114_fix_xv_with_non_gem.patch: Dropped since it caused regression
4/06: 119_drm_bo_unreference_needs_null.patch: Fixes various nullptr derefs
4/08: 120_fix_vt_switch.patch: Fix nullptr deref in video playback
* xserver:
4/08: 177_animated_cursor_change_master.patch: fixes animated cursors
4/06: 174_set_bg_pixmap_of_cow_to_none.patch: Sets bg pixmap of
composite overlay window to None
3/30: 172_cwgetbackingpicture_nullptr_check.patch: fix race condition
when minimzing/maximizing firefox with flash video playing.
* mesa:
4/03: 7.4 released
* Added MESA_GLX_FORCE_DIRECT env var for Xlib/software driver
* GLSL version 1.20 is returnd by the GL_SHADING_LANGUAGE_VERSION query
* glGetActiveUniform() returned wrong size for some array types
* Fixed some error checking in glUniform()
* Fixed a potential glTexImage('proxy target') segfault
* Fixed bad reference counting for 1D/2D texture arrays
* Fixed VBO + glPush/PopClientAttrib() bug #19835
- > * Assorted i965 driver bug fixes
+ * Assorted i965 driver bug fixes
* Fixed a Windows compilation failure in s_triangle.c
* Fixed a GLSL array indexing bug
* Fixes for building on Haiku
* linux:
4/04: 2.6.28-11.41: Revert MCHBAR patch
4/02: 2.6.28-11.40: Add MCHBAR patch
* libdrm:
4/04: 02_libdrm_nouveau_update.patch: Only affects nouveau code
3/29: libdrm-nouveau1.symbols: Probably innocuous
[Workarounds]
Various people have found one or more of the following have helped to reduce
the frequency or eliminate the freezes:
* Turn off compiz
* AccelMethod UXA
* Set NoAccel true
* Set Virtual to something high
* MigrationHeuristic greedy
* Revert to 2.4 -intel driver
[Current Theory]
A 3D memory buffer accumulates data until something gets in there incorrectly
and leads to a freeze. This can happen either slowly over a long period of
light use, or fairly soon if using the system heavily. It is not simply a
matter of filling the memory up, so the trigger often seems to be random, but
usually follows some sort of graphics transition (such as the 3D effect from
alt-tab, or closing a firefox window).
It is fairly certain that there are multiple freeze bugs present in
X.org with the -intel driver. This causes significant confusion when
people having different bugs think they might have the same one, and
find the symptoms and workarounds don't match. It is also suspected
that the same root bug may have multiple different ways of triggering
it.
+ Increasing the Virtual settings seems to either eliminate or greatly
+ reduce the frequency of these freezes. Presumably this allocates larger
+ memory buffers so the chances of something hitting a wrong thing are
+ greatly lessened. However, none of this is well understood.
+
[Original Report]
I am using kubuntu jaunty beta. My system is freezing randomly. I have the
latest updates.
After freezing the mouse pointer still works. And sometimes the power off
button works. On powering off , when the stage for kubuntu logo comes its
showing a distorted image.
This happens with or without desktop effects. These freezes are very
randomly, but mostly when I run some new applications.
I am using intel graphics.
[lspci]
00:00.0 Host bridge [0600]: Intel Corporation Mobile PM965/GM965/GL960 Memory
Controller Hub [8086:2a00] (rev 0c)
Subsystem: Hewlett-Packard Company Device [103c:30be]
00:02.0 VGA compatible controller [0300]: Intel Corporation Mobile
GM965/GL960 Integrated Graphics Controller [8086:2a02] (rev 0c)
Subsystem: Hewlett-Packard Company Device [103c:30be]
--
[i965] X freezes starting on April 3rd
https://bugs.launchpad.net/bugs/359392
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