[PATCH 2/2] drm/i915: Shrink objects prior to hibernation

[Chris Wilson]

In an attempt to keep the hibernation image as same as possible, let's
try and discard any unwanted pages and our own page arrays.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_gem.c | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 04607d4115d6..27e369137946 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4586,7 +4586,12 @@ void i915_gem_load_cleanup(struct drm_device *dev)
 
 int i915_gem_freeze_late(struct drm_i915_private *dev_priv)
 {
-	struct drm_i915_gem_object *obj;
+	struct drm_i915_gem_object *obj, *on;
+	struct list_head *phases[] = {
+		&dev_priv->mm.unbound_list,
+		&dev_priv->mm.bound_list,
+		NULL
+	}, **p;
 
 	/* Called just before we write the hibernation image.
 	 *
@@ -4597,16 +4602,20 @@ int i915_gem_freeze_late(struct drm_i915_private *dev_priv)
 	 *
 	 * To make sure the hibernation image contains the latest state,
 	 * we update that state just before writing out the image.
+	 *
+	 * To try and reduce the hibernation image, we manually shrink
+	 * the objects as well.
 	 */
 
-	list_for_each_entry(obj, &dev_priv->mm.unbound_list, global_list) {
-		obj->base.read_domains = I915_GEM_DOMAIN_CPU;
-		obj->base.write_domain = I915_GEM_DOMAIN_CPU;
-	}
+	for (p = phases; *p; p++) {
+		list_for_each_entry_safe(obj, on, *p, global_list) {
+			/* This is safe as the objects are already idle */
+			if (i915_gem_object_unbind(obj) == 0)
+				i915_gem_object_put_pages(obj);
 
-	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
-		obj->base.read_domains = I915_GEM_DOMAIN_CPU;
-		obj->base.write_domain = I915_GEM_DOMAIN_CPU;
+			obj->base.read_domains = I915_GEM_DOMAIN_CPU;
+			obj->base.write_domain = I915_GEM_DOMAIN_CPU;
+		}
 	}
 
 	return 0;
-- 
2.9.3