[Intel-gfx] [PATCH v6] drm/i915: Cache LRC state page in the context

[Chris Wilson]

On Fri, Jan 15, 2016 at 05:12:45PM +0000, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> LRC lifetime is well defined so we can cache the page pointing
> to the object backing store in the context in order to avoid
> walking over the object SG page list from the interrupt context
> without the big lock held.
> 
> v2: Also cache the mapping. (Chris Wilson)
> v3: Unmap on the error path.
> v4: No need to cache the page. (Chris Wilson)
> v5: No need to dirty the page on unpin. (Chris Wilson)
> v6: kmap() cannot fail and use kmap_to_page to simplify unpin.
>     (Chris Wilson)
> 
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Dave Gordon <david.s.gordon at intel.com>
Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre