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cd9f040df6
The hibernate issues that got fixed in commit985b823b91("drm/i915: fix hibernation since i915 self-reclaim fixes") turn out to have been incomplete. Vefa Bicakci tested lots of hibernate cycles, and without the __GFP_RECLAIMABLE flag the system eventually fails to resume. With the flag added, Vefa can apparently hibernate forever (or until he gets bored running his automated scripts, whichever comes first). The reclaimable flag was there originally, and was one of the flags that were dropped (unintentionally) by commit4bdadb9785("drm/i915: Selectively enable self-reclaim") that introduced all these problems, but I didn't want to just blindly add back all the flags in commit985b823b91, and it looked like __GFP_RECLAIM wasn't necessary. It clearly was. I still suspect that there is some subtle reason we're missing that causes the problems, but __GFP_RECLAIMABLE is certainly not wrong to use in this context, and is what the code historically used. And we have no idea what the causes the corruption without it. Reported-and-tested-by: M. Vefa Bicakci <bicave@superonline.com> Cc: Dave Airlie <airlied@gmail.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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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