[PATCH 55/59] drm/i915: Wire up shrinkctl->nr_scanned

Chris Wilson chris at chris-wilson.co.uk
Mon Oct 2 10:15:04 UTC 2017


shrink_slab() allows us to report back the number of objects we
successfully scanned (out of the target shrinkctl->nr_to_scan). As
report the number of pages owned by each GEM object as a separate item
to the shrinker, we cannot precisely control the number of shrinker
objects we scan on each pass; and indeed may free more than requested.
If we fail to tell the shrinker about the number of objects we process,
it will continue to hold a grudge against us as any objects left
unscanned are added to the next reclaim -- and so we will keep on
"unfairly" shrinking our own slab in comparison to other slabs.

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 cd4a507d5e86..6f15210849fb 100644
--- a/drivers/gpu/drm/i915/i915_gem_shrinker.c
+++ b/drivers/gpu/drm/i915/i915_gem_shrinker.c
@@ -328,8 +328,8 @@ i915_gem_shrink(struct drm_i915_private *dev_priv,
 					count += obj->base.size >> PAGE_SHIFT;
 				}
 				mutex_unlock(&obj->mm.lock);
-				scanned += obj->base.size >> PAGE_SHIFT;
 			}
+			scanned += obj->base.size >> PAGE_SHIFT;
 
 			spin_lock(&dev_priv->mm.obj_lock);
 		}
-- 
2.14.2



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