drm/i915: Stash a pointer to the obj's resv in the vma

During execbuf, a mandatory step is that we add this request (this
fence) to each object's reservation_object. Inside execbuf, we track the
vma, and to add the fence to the reservation_object then means having to
first chase the obj, incurring another cache miss. We can reduce the
 number of cache misses by stashing a pointer to the reservation_object
in the vma itself.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170616140525.6394-1-chris@chris-wilson.co.uk

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/i915_vma.h b/drivers/gpu/drm/i915/i915_vma.h
index 04d7a5da70fd..4a673fc1a432 100644
--- a/drivers/gpu/drm/i915/i915_vma.h
+++ b/drivers/gpu/drm/i915/i915_vma.h
@@ -50,6 +50,7 @@ struct i915_vma {
 	struct drm_i915_gem_object *obj;
 	struct i915_address_space *vm;
 	struct drm_i915_fence_reg *fence;
+	struct reservation_object *resv; /** Alias of obj->resv */
 	struct sg_table *pages;
 	void __iomem *iomap;
 	u64 size;
@@ -111,8 +112,8 @@ struct i915_vma {
 	/**
 	 * Used for performing relocations during execbuffer insertion.
 	 */
-	struct hlist_node exec_node;
 	struct drm_i915_gem_exec_object2 *exec_entry;
+	struct hlist_node exec_node;
 	u32 exec_handle;
 
 	struct i915_gem_context *ctx;