[PATCH 27/27] drm/i915: Flush the freed object list on file close

[Chris Wilson]

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/gem/i915_gem_object.c | 38 +++-------------------
 drivers/gpu/drm/i915/i915_drv.c            |  3 ++
 drivers/gpu/drm/i915/i915_drv.h            |  1 -
 drivers/gpu/drm/i915/i915_gem.c            |  1 -
 4 files changed, 7 insertions(+), 36 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.c b/drivers/gpu/drm/i915/gem/i915_gem_object.c
index cfed28cc6185..27e6633a64cd 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.c
@@ -195,48 +195,18 @@ static void __i915_gem_free_objects(struct drm_i915_private *i915,
 
 void i915_gem_flush_free_objects(struct drm_i915_private *i915)
 {
-	struct llist_node *freed;
-
-	/* Free the oldest, most stale object to keep the free_list short */
-	freed = NULL;
-	if (!llist_empty(&i915->mm.free_list)) { /* quick test for hotpath */
-		/* Only one consumer of llist_del_first() allowed */
-		spin_lock(&i915->mm.free_lock);
-		freed = llist_del_first(&i915->mm.free_list);
-		spin_unlock(&i915->mm.free_lock);
-	}
-	if (unlikely(freed)) {
-		freed->next = NULL;
+	struct llist_node *freed = llist_del_all(&i915->mm.free_list);
+
+	if (unlikely(freed))
 		__i915_gem_free_objects(i915, freed);
-	}
 }
 
 static void __i915_gem_free_work(struct work_struct *work)
 {
 	struct drm_i915_private *i915 =
 		container_of(work, struct drm_i915_private, mm.free_work);
-	struct llist_node *freed;
-
-	/*
-	 * All file-owned VMA should have been released by this point through
-	 * i915_gem_close_object(), or earlier by i915_gem_context_close().
-	 * However, the object may also be bound into the global GTT (e.g.
-	 * older GPUs without per-process support, or for direct access through
-	 * the GTT either for the user or for scanout). Those VMA still need to
-	 * unbound now.
-	 */
-
-	spin_lock(&i915->mm.free_lock);
-	while ((freed = llist_del_all(&i915->mm.free_list))) {
-		spin_unlock(&i915->mm.free_lock);
 
-		__i915_gem_free_objects(i915, freed);
-		if (need_resched())
-			return;
-
-		spin_lock(&i915->mm.free_lock);
-	}
-	spin_unlock(&i915->mm.free_lock);
+	i915_gem_flush_free_objects(i915);
 }
 
 void i915_gem_free_object(struct drm_gem_object *gem_obj)
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index ad61b943e0fe..9b2cee130dd3 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1885,6 +1885,9 @@ static void i915_driver_postclose(struct drm_device *dev, struct drm_file *file)
 	i915_gem_release(dev, file);
 
 	kfree(file_priv);
+
+	/* Catch up with all the deferred frees from "this" client */
+	i915_gem_flush_free_objects(to_i915(dev));
 }
 
 static void intel_suspend_encoders(struct drm_i915_private *dev_priv)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 47d0c9d6365e..932b152d5ba7 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -767,7 +767,6 @@ struct i915_gem_mm {
 	 */
 	struct llist_head free_list;
 	struct work_struct free_work;
-	spinlock_t free_lock;
 	/**
 	 * Count of objects pending destructions. Used to skip needlessly
 	 * waiting on an RCU barrier if no objects are waiting to be freed.
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 31a6aa7e4837..4e090e1d5641 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1647,7 +1647,6 @@ void i915_gem_init_mmio(struct drm_i915_private *i915)
 static void i915_gem_init__mm(struct drm_i915_private *i915)
 {
 	spin_lock_init(&i915->mm.obj_lock);
-	spin_lock_init(&i915->mm.free_lock);
 
 	init_llist_head(&i915->mm.free_list);
 
-- 
2.22.0