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

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

On Sun, 2014-07-06 at 18:29 +0530, sourab gupta wrote:
> 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

Hi,
Can you please review this patch series.
Thanks,
Sourab