[Intel-gfx] [PATCH 1/2 v2] drm/i915: mark GEM object pages dirty when mapped & written by the CPU

[Chris Wilson]

On Fri, Dec 11, 2015 at 06:08:10PM +0100, Daniel Vetter wrote:
> Hm, I think if you force a fault on relocs and then shrink everything
> really hard before actually managing to submit the batch you could provoke
> this into a proper bug. one-in-a-billion perhaps ;-)

Hmm, you would need to force the slowpath (otherwise all the objects are
reserved and so not swappable). And then we force the presumed_offset to
be invalid but only on the user side - so we don't force the relocations
in this batch. Ok, plausible. But who hits the slowpath? Sigh. Fancy
reviewing some mesa patches?
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre