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As the execbuffer dispatch grows ever more complex and involves multiple stages of moving objects into the aperture, we need to take greater care that we do not evict our execbuffer objects prior to dispatch. This is relatively simple as we can just keep the objects pinned for not just the relocation but until we are finished. One such example is the possibility of the context switch causing an eviction or hitting the shrinker in order to fit its object into the aperture. Link: http://lists.freedesktop.org/archives/intel-gfx/2013-November/036166.html Reported-by: "Siluvery, Arun" <arun.siluvery@intel.com> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Ben Widawsky <benjamin.widawsky@intel.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: stable@vger.kernel.org Acked-by: Ben Widawsky <ben@bwidawsk.net> Tested-by: Ben Widawsky <ben@bwidawsk.net> [danvet: Add the additional explanations from Chris to the commit message.] Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
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* For the very latest on DRI development, please see: *
* http://dri.freedesktop.org/ *
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The Direct Rendering Manager (drm) is a device-independent kernel-level
device driver that provides support for the XFree86 Direct Rendering
Infrastructure (DRI).
The DRM supports the Direct Rendering Infrastructure (DRI) in four major
ways:
1. The DRM provides synchronized access to the graphics hardware via
the use of an optimized two-tiered lock.
2. The DRM enforces the DRI security policy for access to the graphics
hardware by only allowing authenticated X11 clients access to
restricted regions of memory.
3. The DRM provides a generic DMA engine, complete with multiple
queues and the ability to detect the need for an OpenGL context
switch.
4. The DRM is extensible via the use of small device-specific modules
that rely extensively on the API exported by the DRM module.
Documentation on the DRI is available from:
http://dri.freedesktop.org/wiki/Documentation
http://sourceforge.net/project/showfiles.php?group_id=387
http://dri.sourceforge.net/doc/
For specific information about kernel-level support, see:
The Direct Rendering Manager, Kernel Support for the Direct Rendering
Infrastructure
http://dri.sourceforge.net/doc/drm_low_level.html
Hardware Locking for the Direct Rendering Infrastructure
http://dri.sourceforge.net/doc/hardware_locking_low_level.html
A Security Analysis of the Direct Rendering Infrastructure
http://dri.sourceforge.net/doc/security_low_level.html