[Intel-gfx] Bus error in _mesa_texstore_argb8888

[Chris Wilson]

On Fri, 24 Feb 2012 11:39:02 +0100, tomw <tomw at ubilix.com> wrote:
> Hi,
> 
> after loading quite some objects from a ClutterListModel into a
> ClutterListView I'm running into a Bus error as soon as I try to render
> the Listview. As far as I read the gdb output it happens either in
> _mesa_texstore_argb8888. Pls. see the gdb trace below. Is there a way to
> fix it by configuration or is it rather a bug in the code. I'm using the
> latest Q4 stack on an i3-2100T. The Bus error only happens if the number
> of objects exceeds a certain level (> ~70 objects with images and text).

It's a bug in the driver in that it tries to use a GTT mapping on an
8k x 8k object which is the size of the mappable aperture and has no
fallback to handle the failure to fault in the page for writing. Either
mesa or the kernel needs to provide some form of trampolining for such large
bo, or for the kernel to provide a mechanism to only map a rectangular part
of the buffer.

Alternatively, you can see if you can instruct clutter not to generate
such large texture atlases, which is still a heuristic to second guess
the driver...
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre