[Intel-gfx] [PATCH] drm/i915: Only move to the CPU write domain if keeping the GTT pages

[Chris Wilson]

On Sun, Aug 09, 2015 at 04:23:01PM +0530, Goel, Akash wrote:
> On 8/7/2015 1:37 PM, Daniel Vetter wrote:
> >I presume though you only want to avoid clflush when actually purging an
> >object, so maybe we can keep this by purging the shmem backing node first
> >and checking here for __I915_MADV_PURGED instead?
> 
> An object marked as MADV_DONT_NEED, implies that it will be
> purged/truncated right away after the call to put_pages_gtt
> function.
> So doing the other way round by purging first and then checking for
> __I915_MADV_PURGED, might be equivalent.

But disregards a few nice sanity checks, which I would like to keep.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre