[Intel-gfx] [PATCH] drm/i915: Only GGTT vma may be pinned and prevent shrinking

[Chris Wilson]

As only GGTT vma may be permanently pinned and are always at the head of
the object's vma list, as soon as we seen a ppGTT vma we can stop
searching for any_vma_pinned().

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_gem_shrinker.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_shrinker.c b/drivers/gpu/drm/i915/i915_gem_shrinker.c
index 9fe4d0c66549..6dfe66c96081 100644
--- a/drivers/gpu/drm/i915/i915_gem_shrinker.c
+++ b/drivers/gpu/drm/i915/i915_gem_shrinker.c
@@ -66,9 +66,17 @@ static bool any_vma_pinned(struct drm_i915_gem_object *obj)
 {
 	struct i915_vma *vma;
 
-	list_for_each_entry(vma, &obj->vma_list, obj_link)
+	list_for_each_entry(vma, &obj->vma_list, obj_link) {
+		/* Only GGTT vma may be permanently pinned, and are always
+		 * at the start of the list. We can stop hunting as soon
+		 * as we see a ppGTT vma.
+		 */
+		if (!i915_vma_is_ggtt(vma))
+			break;
+
 		if (i915_vma_is_pinned(vma))
 			return true;
+	}
 
 	return false;
 }
-- 
2.11.0