diff mbox series

[CI,6/6] drm/i915/gem: Drop lru bumping on display unpinning

Message ID 20210119214336.1463-6-chris@chris-wilson.co.uk (mailing list archive)
State New, archived
Headers show
Series [CI,1/6] drm/i915/gem: Almagamate clflushes on suspend | expand

Commit Message

Chris Wilson Jan. 19, 2021, 9:43 p.m. UTC 
Simplify the frontbuffer unpin by removing the lock requirement. The LRU
bumping was primarily to protect the GTT from being evicted and from
frontbuffers being eagerly shrunk. Now we protect frontbuffers from the
shrinker, and we avoid accidentally evicting from the GTT, so the
benefit from bumping LRU is no more, and we can save more time by not.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
---
 drivers/gpu/drm/i915/display/intel_display.c |  7 +--
 drivers/gpu/drm/i915/display/intel_overlay.c |  4 +-
 drivers/gpu/drm/i915/gem/i915_gem_domain.c   | 45 --------------------
 drivers/gpu/drm/i915/gem/i915_gem_object.h   |  1 -
 4 files changed, 4 insertions(+), 53 deletions(-)

Comments

Dave Airlie Feb. 8, 2021, 8:09 p.m. UTC | #1 
On Wed, 20 Jan 2021 at 07:43, Chris Wilson <chris@chris-wilson.co.uk> wrote:
>
> Simplify the frontbuffer unpin by removing the lock requirement. The LRU
> bumping was primarily to protect the GTT from being evicted and from
> frontbuffers being eagerly shrunk. Now we protect frontbuffers from the
> shrinker, and we avoid accidentally evicting from the GTT, so the
> benefit from bumping LRU is no more, and we can save more time by not.
>
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> Reviewed-by: Matthew Auld <matthew.auld@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c |  7 +--
>  drivers/gpu/drm/i915/display/intel_overlay.c |  4 +-
>  drivers/gpu/drm/i915/gem/i915_gem_domain.c   | 45 --------------------
>  drivers/gpu/drm/i915/gem/i915_gem_object.h   |  1 -
>  4 files changed, 4 insertions(+), 53 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 32ff9d201aeb..2bd04e631eaa 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -1430,7 +1430,7 @@ intel_pin_and_fence_fb_obj(struct drm_framebuffer *fb,
>                  */
>                 ret = i915_vma_pin_fence(vma);
>                 if (ret != 0 && INTEL_GEN(dev_priv) < 4) {
> -                       i915_gem_object_unpin_from_display_plane(vma);
> +                       i915_vma_unpin(vma);
>                         vma = ERR_PTR(ret);
>                         goto err;
>                 }
> @@ -1448,12 +1448,9 @@ intel_pin_and_fence_fb_obj(struct drm_framebuffer *fb,
>
>  void intel_unpin_fb_vma(struct i915_vma *vma, unsigned long flags)
>  {
> -       i915_gem_object_lock(vma->obj, NULL);
>         if (flags & PLANE_HAS_FENCE)
>                 i915_vma_unpin_fence(vma);
> -       i915_gem_object_unpin_from_display_plane(vma);
> -       i915_gem_object_unlock(vma->obj);
> -

Why does this drop the locking here without explanation and without
reviewer comments?

Any patches from Chris that touch locking need vastly more review than
rubberstamps.

Dave.
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 32ff9d201aeb..2bd04e631eaa 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -1430,7 +1430,7 @@  intel_pin_and_fence_fb_obj(struct drm_framebuffer *fb,
 		 */
 		ret = i915_vma_pin_fence(vma);
 		if (ret != 0 && INTEL_GEN(dev_priv) < 4) {
-			i915_gem_object_unpin_from_display_plane(vma);
+			i915_vma_unpin(vma);
 			vma = ERR_PTR(ret);
 			goto err;
 		}
@@ -1448,12 +1448,9 @@  intel_pin_and_fence_fb_obj(struct drm_framebuffer *fb,
 
 void intel_unpin_fb_vma(struct i915_vma *vma, unsigned long flags)
 {
-	i915_gem_object_lock(vma->obj, NULL);
 	if (flags & PLANE_HAS_FENCE)
 		i915_vma_unpin_fence(vma);
-	i915_gem_object_unpin_from_display_plane(vma);
-	i915_gem_object_unlock(vma->obj);
-
+	i915_vma_unpin(vma);
 	i915_vma_put(vma);
 }
 
diff --git a/drivers/gpu/drm/i915/display/intel_overlay.c b/drivers/gpu/drm/i915/display/intel_overlay.c
index 6be5d8946c69..8edb9b2cdbeb 100644
--- a/drivers/gpu/drm/i915/display/intel_overlay.c
+++ b/drivers/gpu/drm/i915/display/intel_overlay.c
@@ -360,7 +360,7 @@  static void intel_overlay_release_old_vma(struct intel_overlay *overlay)
 	intel_frontbuffer_flip_complete(overlay->i915,
 					INTEL_FRONTBUFFER_OVERLAY(overlay->crtc->pipe));
 
-	i915_gem_object_unpin_from_display_plane(vma);
+	i915_vma_unpin(vma);
 	i915_vma_put(vma);
 }
 
@@ -861,7 +861,7 @@  static int intel_overlay_do_put_image(struct intel_overlay *overlay,
 	return 0;
 
 out_unpin:
-	i915_gem_object_unpin_from_display_plane(vma);
+	i915_vma_unpin(vma);
 out_pin_section:
 	atomic_dec(&dev_priv->gpu_error.pending_fb_pin);
 
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_domain.c b/drivers/gpu/drm/i915/gem/i915_gem_domain.c
index a6257314be9c..36f54cedaaeb 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_domain.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_domain.c
@@ -434,48 +434,6 @@  i915_gem_object_pin_to_display_plane(struct drm_i915_gem_object *obj,
 	return vma;
 }
 
-static void i915_gem_object_bump_inactive_ggtt(struct drm_i915_gem_object *obj)
-{
-	struct drm_i915_private *i915 = to_i915(obj->base.dev);
-	struct i915_vma *vma;
-
-	if (list_empty(&obj->vma.list))
-		return;
-
-	mutex_lock(&i915->ggtt.vm.mutex);
-	spin_lock(&obj->vma.lock);
-	for_each_ggtt_vma(vma, obj) {
-		if (!drm_mm_node_allocated(&vma->node))
-			continue;
-
-		GEM_BUG_ON(vma->vm != &i915->ggtt.vm);
-		list_move_tail(&vma->vm_link, &vma->vm->bound_list);
-	}
-	spin_unlock(&obj->vma.lock);
-	mutex_unlock(&i915->ggtt.vm.mutex);
-
-	if (i915_gem_object_is_shrinkable(obj)) {
-		unsigned long flags;
-
-		spin_lock_irqsave(&i915->mm.obj_lock, flags);
-
-		if (obj->mm.madv == I915_MADV_WILLNEED &&
-		    !atomic_read(&obj->mm.shrink_pin))
-			list_move_tail(&obj->mm.link, &i915->mm.shrink_list);
-
-		spin_unlock_irqrestore(&i915->mm.obj_lock, flags);
-	}
-}
-
-void
-i915_gem_object_unpin_from_display_plane(struct i915_vma *vma)
-{
-	/* Bump the LRU to try and avoid premature eviction whilst flipping  */
-	i915_gem_object_bump_inactive_ggtt(vma->obj);
-
-	i915_vma_unpin(vma);
-}
-
 /**
  * Moves a single object to the CPU read, and possibly write domain.
  * @obj: object to act on
@@ -616,9 +574,6 @@  i915_gem_set_domain_ioctl(struct drm_device *dev, void *data,
 	else
 		err = i915_gem_object_set_to_cpu_domain(obj, write_domain);
 
-	/* And bump the LRU for this access */
-	i915_gem_object_bump_inactive_ggtt(obj);
-
 	i915_gem_object_unlock(obj);
 
 	if (write_domain)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h
index 0004893450c7..77b2c36b7dac 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h
@@ -492,7 +492,6 @@  i915_gem_object_pin_to_display_plane(struct drm_i915_gem_object *obj,
 				     u32 alignment,
 				     const struct i915_ggtt_view *view,
 				     unsigned int flags);
-void i915_gem_object_unpin_from_display_plane(struct i915_vma *vma);
 
 void i915_gem_object_make_unshrinkable(struct drm_i915_gem_object *obj);
 void i915_gem_object_make_shrinkable(struct drm_i915_gem_object *obj);