Re: [PATCH] drm/i915: Flush pending GTT writes before unbinding

[Joonas Lahtinen <joonas.lahtinen@linux.intel.com>]

On Mon, 2017-12-04 at 12:43 +0000, Chris Wilson wrote:
> From the shrinker paths, we want to relinquish the GPU and GGTT access to
> the object, releasing the backing storage back to the system for
> swapout. As a part of that process we would unpin the pages, marking
> them for access by the CPU (for the swapout/swapin). However, if that
> process was interrupted after unbind the vma, we missed a flush of the
> inflight GGTT writes before we made that GTT space available again for
> reuse, with the prospect that we would redirect them to another page.
> 
> The bug dates back to the introduction of multiple GGTT vma, but the
> code itself dates to commit 02bef8f98d26 ("drm/i915: Unbind closed vma
> for i915_gem_object_unbind()").
> 
> Fixes: 02bef8f98d26 ("drm/i915: Unbind closed vma for i915_gem_object_unbind()")
> Fixes: c5ad54cf7dd8 ("drm/i915: Use partial view in mmap fault handler")
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
> Cc: stable@vger.kernel.org

Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

Regards, Joonas
-- 
Joonas Lahtinen
Open Source Technology Center
Intel Corporation