Re: [PATCH 0/4] Introduce a new create ioctl for user specified

["Gupta, Sourab" <sourab.gupta@intel.com>]

On Fri, 2014-06-20 at 10:02 +0000, Gupta, Sourab wrote:
> From: Sourab Gupta <sourab.gupta@intel.com>
> 
> This patch series introduces a new gem create ioctl for user specified
> placement.
> 
> Despite being a unified memory architecture (UMA) some bits of memory
> are more equal than others. In particular we have the thorny issue of
> stolen memory, memory stolen from the system by the BIOS and reserved
> for igfx use. Stolen memory is required for some functions of the GPU
> and display engine, but in general it goes wasted. Whilst we cannot
> return it back to the system, we need to find some other method for
> utilising it. As we do not support direct access to the physical address
> in the stolen region, it behaves like a different class of memory,
> closer in kin to local GPU memory. This strongly suggests that we need a
> placement model like TTM if we are to fully utilize these discrete
> chunks of differing memory.
>     
> This new create ioctl therefore exists to allow the user to create these
> second class buffer objects from stolen memory. At the moment direct
> access by the CPU through mmaps and pread/pwrite are verboten on the
> objects, and so the user must be aware of the limitations of the objects
> created. Yet, those limitations rarely reduce the desired functionality
> in many use cases and so the user should be able to easily fill the
> stolen memory and so help to reduce overall memory pressure.
>     
> The most obvious use case for stolen memory is for the creation of objects
> for the display engine which already have very similar restrictions on
> access. However, we want a reasonably general ioctl in order to cater
> for diverse scenarios beyond the author's imagination.
> 
> Chris Wilson (3):
>   drm/i915: Clearing buffer objects via blitter engine
>   drm/i915: Introduce a new create ioctl for user specified placement
>   drm/i915: Add support for stealing purgable stolen pages
> 
> Deepak S (1):
>   drm/i915: Clearing buffer objects via blitter engine for Gen8
> 
>  drivers/gpu/drm/i915/Makefile          |   1 +
>  drivers/gpu/drm/i915/i915_dma.c        |   5 +-
>  drivers/gpu/drm/i915/i915_drv.h        |  18 ++-
>  drivers/gpu/drm/i915/i915_gem.c        | 208 ++++++++++++++++++++++++++++++---
>  drivers/gpu/drm/i915/i915_gem_exec.c   | 139 ++++++++++++++++++++++
>  drivers/gpu/drm/i915/i915_gem_stolen.c | 121 +++++++++++++++++--
>  drivers/gpu/drm/i915/i915_gem_tiling.c | 106 +++++++++--------
>  include/uapi/drm/i915_drm.h            | 107 +++++++++++++++++
>  8 files changed, 623 insertions(+), 82 deletions(-)
>  create mode 100644 drivers/gpu/drm/i915/i915_gem_exec.c
> 

Hi,
Can somebody please review this patch series, alongwith the libdrm
changes(http://lists.freedesktop.org/archives/intel-gfx/2014-June/047296.html) and igt (http://lists.freedesktop.org/archives/intel-gfx/2014-June/047295.html)

Thanks,
Sourab