[Intel-gfx] [PATCH 3/3] drm/i915: Use insert_page for pwrite_fast

[Ankitprasad Sharma]

On Wed, 2015-11-18 at 10:59 +0100, Daniel Vetter wrote:
> On Thu, Nov 05, 2015 at 05:15:59PM +0530, ankitprasad.r.sharma at intel.com wrote:
> > From: Ankitprasad Sharma <ankitprasad.r.sharma at intel.com>
> > 
> > In pwrite_fast, map an object page by page if obj_ggtt_pin fails. First,
> > we try a nonblocking pin for the whole object (since that is fastest if
> > reused), then failing that we try to grab one page in the mappable
> > aperture. It also allows us to handle objects larger than the mappable
> > aperture (e.g. if we need to pwrite with vGPU restricting the aperture
> > to a measely 8MiB or something like that).
> 
> We already have a fallback to the shmem pwrite. Why do we need this?
This is mainly for the non-shmem backed objects, as we do not have
fallback path for that. Agree for the shmem backed objects, as we
already have a fallback.

Would like to request Chris, if he can clarify further.

Thanks, 
Ankit