[Intel-gfx] [PATCH 2/2 v2] drm/i915: mark GEM objects dirty after overwriting their contents

[Chris Wilson]

On Thu, Dec 10, 2015 at 03:06:55PM +0100, Daniel Vetter wrote:
> On Wed, Dec 09, 2015 at 03:52:52PM +0000, Dave Gordon wrote:
> > In a few places, we fill a GEM object with data, or overwrite some
> > portion of its contents other than a single page. In such cases, we
> > should mark the object dirty so that its pages in the pagecache are
> > written to backing store (rather than discarded) if the object is
> > evicted due to memory pressure.
> > 
> > The cases where only a single page is touched are dealt with in a
> > separate patch.
> > 
> > This incorporates and supercedes Alex Dai's earlier patch
> > [PATCH v1] drm/i915/guc: Fix a fw content lost issue after it is evicted
> > 
> > Signed-off-by: Dave Gordon <david.s.gordon at intel.com>
> > Cc: Alex Dai <yu.dai at intel.com>
> > Cc: Chris Wilson <chris at chris-wilson.co.uk>
> 
> Hm, did you drop the begin_cpu_access dma-buf one here? See my other mail,
> I think that one was legit.

I thought begin-access was the sync point around the per-page mmap(),
but reading the current code "in kernel users", of which it is just
drm/udl. How would we interact with a future dma-buf mmap()?
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre