[Intel-gfx] [PATCH v2] drm/i915: Assert we do not try to expand VMA for hugepage inside GGTT

[Joonas Lahtinen]

On Mon, 2017-10-09 at 10:20 +0100, Chris Wilson wrote:
> We only apply the hugepage PD redirection inside the ppGTT, so during
> i915_vma_insert() we want to exclude the GGTT from the additional
> alignment constraints (thereby avoiding the extra GTT pressure from
> fragmentation). Add an assert to document that intention alongside the
> comment.
> 
> v2: After discussion with Matthew, make it a blanket GGTT ban
> (previously we allowed the expansion for appgtt, and so indirectly
> ggtt). There are issues we need to fix before allowing the current
> appgtt to be used with hugepages, and if we do, we probably want more
> care over when to expand/align, as the mappable aperture inside the ggtt
> is precious.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Matthew Auld <matthew.william.auld at gmail.com>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> Reviewed-by: Matthew Auld <matthew.william.auld at gmail.com>

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

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