[Intel-gfx] [RFC 2/3] drm/i915: Track aggregate per-object VMA pin count

[Tvrtko Ursulin]

From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

This allows trivial (non-iterating) i915_gem_obj_is_pinned
implementation which in turns prevents i915_gem_madvise_ioctl
showing up in profiles in benchmarks like SynMark2/OglDrvCtx.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h            |  9 ++++++++-
 drivers/gpu/drm/i915/i915_gem.c            | 15 +++++----------
 drivers/gpu/drm/i915/i915_gem_execbuffer.c |  4 +++-
 3 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 6f1e0f127c0a..589256e2ebe9 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2104,6 +2104,9 @@ struct drm_i915_gem_object {
 	/** List of VMAs backed by this object */
 	struct list_head vma_list;
 
+	/** Aggregate pin count of all VMAs backed by this object. */
+	unsigned int vma_pin_count;
+
 	/** Stolen memory for this object, instead of being backed by shmem. */
 	struct drm_mm_node *stolen;
 	struct list_head global_list;
@@ -3236,7 +3239,11 @@ i915_gem_obj_to_ggtt(struct drm_i915_gem_object *obj)
 {
 	return i915_gem_obj_to_ggtt_view(obj, &i915_ggtt_view_normal);
 }
-bool i915_gem_obj_is_pinned(struct drm_i915_gem_object *obj);
+
+static inline bool i915_gem_obj_is_pinned(struct drm_i915_gem_object *obj)
+{
+	return obj->vma_pin_count > 0;
+}
 
 /* Some GGTT VM helpers */
 static inline struct i915_hw_ppgtt *
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 261a3ef72828..0549dea683e1 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4311,6 +4311,8 @@ i915_gem_object_do_pin(struct drm_i915_gem_object *obj,
 	}
 
 	vma->pin_count++;
+	obj->vma_pin_count++;
+
 	return 0;
 }
 
@@ -4351,6 +4353,7 @@ i915_gem_object_ggtt_unpin_view(struct drm_i915_gem_object *obj,
 	WARN_ON(!i915_gem_obj_ggtt_bound_view(obj, view));
 
 	--vma->pin_count;
+	--obj->vma_pin_count;
 }
 
 int
@@ -4583,6 +4586,8 @@ void i915_gem_free_object(struct drm_gem_object *gem_obj)
 	list_for_each_entry_safe(vma, next, &obj->vma_list, obj_link) {
 		int ret;
 
+		GEM_BUG_ON(obj->vma_pin_count < vma->pin_count);
+		obj->vma_pin_count -= vma->pin_count;
 		vma->pin_count = 0;
 		ret = i915_vma_unbind(vma);
 		if (WARN_ON(ret == -ERESTARTSYS)) {
@@ -5326,16 +5331,6 @@ unsigned long i915_gem_obj_size(struct drm_i915_gem_object *o,
 	return 0;
 }
 
-bool i915_gem_obj_is_pinned(struct drm_i915_gem_object *obj)
-{
-	struct i915_vma *vma;
-	list_for_each_entry(vma, &obj->vma_list, obj_link)
-		if (vma->pin_count > 0)
-			return true;
-
-	return false;
-}
-
 /* Like i915_gem_object_get_page(), but mark the returned page dirty */
 struct page *
 i915_gem_object_get_dirty_page(struct drm_i915_gem_object *obj, int n)
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 6f4f2a6cdf93..b4c787763955 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -218,8 +218,10 @@ i915_gem_execbuffer_unreserve_vma(struct i915_vma *vma)
 	if (entry->flags & __EXEC_OBJECT_HAS_FENCE)
 		i915_gem_object_unpin_fence(obj);
 
-	if (entry->flags & __EXEC_OBJECT_HAS_PIN)
+	if (entry->flags & __EXEC_OBJECT_HAS_PIN) {
 		vma->pin_count--;
+		obj->vma_pin_count--;
+	}
 
 	entry->flags &= ~(__EXEC_OBJECT_HAS_FENCE | __EXEC_OBJECT_HAS_PIN);
 }
-- 
1.9.1