[Intel-gfx] [PATCH 16/16] drm/i915: Introduce mapping of user pages into video memory (userptr) ioctl

[Chris Wilson]

On Sat, 1 Dec 2012 00:06:43 +0100, Daniel Vetter <daniel at ffwll.ch> wrote:
> Quick review:
> - I don't like the internal byte offset we add/substract for relocations.
>   mmap works on page boundaries, imo gpu mmap should do the same.

However, the necessity is that I work on unaligned boundaries since I
have no control over how the clients allocate the memory to be mapped,
or which bytes within that memory are associated with a particular
pixmap. The XShm API is such that not even the ShmSegment is passed down
to the driver. That vies with the lack of explicit synchronisation
points as being the worst elements of its design.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre