You should try glamor from git:
http://cgit.freedesktop.org/xorg/driver/glamor/

(In reply to comment #0)
> When I use a lot of Graphics objects in Mathematica -- the help page of the
> Manipulate operation has a ton -- and scroll through the list, 1 out of 10
> times, X crashes with the following trace:
> 
> [427236.328] (EE) 
> [427236.328] (EE) Backtrace:
> [427236.380] (EE) 0: /usr/bin/X (xorg_backtrace+0x3d) [0x57f67d]
> [427236.380] (EE) 1: /usr/bin/X (0x400000+0x1833e9) [0x5833e9]
> [427236.380] (EE) 2: /usr/lib/libpthread.so.0 (0x7f799d407000+0xf870)
> [0x7f799d416870]
> [427236.380] (EE) 3: /usr/lib/libglamor.so.0 (0x7f799aad8000+0x11e41)
> [0x7f799aae9e41]
> [427236.380] (EE) 4: /usr/lib/libglamor.so.0 (0x7f799aad8000+0x147bf)
> [0x7f799aaec7bf]
> [427236.380] (EE) 5: /usr/lib/libglamor.so.0 (0x7f799aad8000+0x9412)
> [0x7f799aae1412]
> [427236.380] (EE) 6: /usr/lib/libglamor.so.0 (0x7f799aad8000+0xb99c)
> [0x7f799aae399c]
> [427236.380] (EE) 7: /usr/bin/X (0x400000+0x10bb96) [0x50bb96]
> [427236.380] (EE) 8: /usr/bin/X (0x400000+0x10573e) [0x50573e]
> [427236.380] (EE) 9: /usr/bin/X (0x400000+0x373be) [0x4373be]
> [427236.380] (EE) 10: /usr/bin/X (0x400000+0x2693a) [0x42693a]
> [427236.380] (EE) 11: /usr/lib/libc.so.6 (__libc_start_main+0xf5)
> [0x7f799c48abc5]
> [427236.380] (EE) 12: /usr/bin/X (0x400000+0x26c81) [0x426c81]
> [427236.380] (EE) 
> [427236.380] (EE) Segmentation fault at address 0x0
> [427236.380] (EE) 
> Fatal server error:
> [427236.380] (EE) Caught signal 11 (Segmentation fault). Server aborting
> [427236.380] (EE) 
> [427236.380] (EE) 
> Please consult the The X.Org Foundation support 
>          at http://wiki.x.org
>  for help. 
> [427236.380] (EE) Please also check the log file at "/var/log/Xorg.0.log"
> for additional information.
> [427236.380] (EE)
> 
> Here are the relevant symbol map lines:
> 
> 0000000000011920 t glamor_composite_with_shader
> 0000000000012530 t glamor_convert_gradient_picture
> ...
> 00000000000141e0 t glamor_composite_glyph_rects
> 00000000000148b0 t glamor_composite_rects
> ...
> 00000000000093c0 t glamor_glyphs_flush_dst
> 0000000000009450 t glamor_buffer_glyph
> ...
> 000000000000af90 t _glamor_glyphs.isra.12
> 000000000000be70 t glamor_glyphs_fini
> 
> I am running 0.5.1 with this patch:
> https://bugs.freedesktop.org/show_bug.cgi?id=64912
> 
> I recompiled with debug symbols and waiting for the next crash..

could you give a try with git master version? And if it crash again, please provide full gdb back trace information. Thanks.

That's somewhat old bug and I can recall that I tried to produce a meaningful stack trace and didn't get particularly far.

I have not seen this type of crash since then with Mathematica. I am affected by  https://bugs.freedesktop.org/show_bug.cgi?id=79696 however. But since this other bug looks unrelated, I am closing this one as fixed.

Thanks everyone.