[PATCH 5/5] drm/i915: Move the recently scanned objects to the tail after shrinking

[Chris Wilson]

During shrinking, we walk over the list of objects searching for
victims. Any that are not removed are put back into the global list.
Currently, they are put back in order (at the front) which means they
will be first to be scanned again. If we instead move them to the rear
of the list, we will scan new potential victims on the next pass and
waste less time rescanning unshrinkable objects. Normally the lists are
kept in rough order to shrinking (with object least frequently used at
the start), by moving just scanned objects to the rear we are
acknowledging that they are still in use.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_gem_shrinker.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_shrinker.c b/drivers/gpu/drm/i915/i915_gem_shrinker.c
index b504ba091c4f..f4a1515737bd 100644
--- a/drivers/gpu/drm/i915/i915_gem_shrinker.c
+++ b/drivers/gpu/drm/i915/i915_gem_shrinker.c
@@ -232,7 +232,7 @@ i915_gem_shrink(struct drm_i915_private *dev_priv,
 				mutex_unlock(&obj->mm.lock);
 			}
 		}
-		list_splice(&still_in_list, phase->list);
+		list_splice_tail(&still_in_list, phase->list);
 	}
 
 	if (flags & I915_SHRINK_BOUND)
-- 
2.10.1