[Mesa-dev] [PATCH] anv/cmd_buffer: Avoid unnecessary transitions before fast clears

Jason Ekstrand jason at jlekstrand.net
Mon Feb 26 02:32:56 UTC 2018


Previously, we would always apply the layout transition at the beginning
of the subpass and then do the clear whether fast or slow.  This meant
that there were some cases, specifically when the initial layout is
VK_IMAGE_LAYOUT_UNDEFINED, where we would end up doing a fast-clear or
ambiguate followed immediately by a fast-clear.  This isn't usually
terribly expensive, but it is a waste that we can avoid easily enough
now that we're doing everything at the same time in begin_subpass.

This improves the performance of the Sascha multisampling demo on my
laptop by around 10% by avoiding a duplicate MCS clear.
---
 src/intel/vulkan/genX_cmd_buffer.c | 158 ++++++++++++++++++++++++-------------
 1 file changed, 101 insertions(+), 57 deletions(-)

diff --git a/src/intel/vulkan/genX_cmd_buffer.c b/src/intel/vulkan/genX_cmd_buffer.c
index 98e58ca..743c25c0 100644
--- a/src/intel/vulkan/genX_cmd_buffer.c
+++ b/src/intel/vulkan/genX_cmd_buffer.c
@@ -3436,43 +3436,24 @@ cmd_buffer_begin_subpass(struct anv_cmd_buffer *cmd_buffer,
          target_layout = subpass->attachments[i].layout;
       }
 
-      if (image->aspects & VK_IMAGE_ASPECT_ANY_COLOR_BIT_ANV) {
-         assert(image->aspects == VK_IMAGE_ASPECT_COLOR_BIT);
-
-         uint32_t base_layer, layer_count;
-         if (image->type == VK_IMAGE_TYPE_3D) {
-            base_layer = 0;
-            layer_count = anv_minify(iview->image->extent.depth,
-                                     iview->planes[0].isl.base_level);
-         } else {
-            base_layer = iview->planes[0].isl.base_array_layer;
-            layer_count = fb->layers;
-         }
-
-         transition_color_buffer(cmd_buffer, image, VK_IMAGE_ASPECT_COLOR_BIT,
-                                 iview->planes[0].isl.base_level, 1,
-                                 base_layer, layer_count,
-                                 att_state->current_layout, target_layout);
-      } else if (image->aspects & VK_IMAGE_ASPECT_DEPTH_BIT) {
-         transition_depth_buffer(cmd_buffer, image,
-                                 att_state->current_layout, target_layout);
-         att_state->aux_usage =
-            anv_layout_to_aux_usage(&cmd_buffer->device->info, image,
-                                    VK_IMAGE_ASPECT_DEPTH_BIT, target_layout);
+      uint32_t base_layer, layer_count;
+      if (image->type == VK_IMAGE_TYPE_3D) {
+         base_layer = 0;
+         layer_count = anv_minify(iview->image->extent.depth,
+                                  iview->planes[0].isl.base_level);
+      } else {
+         base_layer = iview->planes[0].isl.base_array_layer;
+         layer_count = fb->layers;
       }
-      att_state->current_layout = target_layout;
-
-      if (att_state->pending_clear_aspects & VK_IMAGE_ASPECT_COLOR_BIT) {
-         assert(att_state->pending_clear_aspects == VK_IMAGE_ASPECT_COLOR_BIT);
-
-         /* Multi-planar images are not supported as attachments */
-         assert(image->aspects == VK_IMAGE_ASPECT_COLOR_BIT);
-         assert(image->n_planes == 1);
 
-         uint32_t base_clear_layer = iview->planes[0].isl.base_array_layer;
-         uint32_t clear_layer_count = fb->layers;
+      /* Clears are based on the image view for 3D surfaces but transitions
+       * are done on an entire miplevel at a time.
+       */
+      uint32_t base_clear_layer = iview->planes[0].isl.base_array_layer;
+      uint32_t clear_layer_count = fb->layers;
 
-         if (att_state->fast_clear) {
+      if (att_state->fast_clear) {
+         if (att_state->pending_clear_aspects & VK_IMAGE_ASPECT_COLOR_BIT) {
             /* We only support fast-clears on the first layer */
             assert(iview->planes[0].isl.base_level == 0);
             assert(iview->planes[0].isl.base_array_layer == 0);
@@ -3484,9 +3465,17 @@ cmd_buffer_begin_subpass(struct anv_cmd_buffer *cmd_buffer,
                anv_image_mcs_op(cmd_buffer, image, VK_IMAGE_ASPECT_COLOR_BIT,
                                 0, 1, ISL_AUX_OP_FAST_CLEAR, false);
             }
+
             base_clear_layer++;
             clear_layer_count--;
 
+            /* Performing a fast clear takes care of all our transition needs
+             * for the first slice.  Increment the base layer and layer count
+             * so that later transitions don't touch layer 0.
+             */
+            base_layer++;
+            layer_count--;
+
             genX(copy_fast_clear_dwords)(cmd_buffer, att_state->color.state,
                                          image, VK_IMAGE_ASPECT_COLOR_BIT,
                                          true /* copy from ss */);
@@ -3507,6 +3496,59 @@ cmd_buffer_begin_subpass(struct anv_cmd_buffer *cmd_buffer,
             }
          }
 
+         if ((att_state->pending_clear_aspects & VK_IMAGE_ASPECT_DEPTH_BIT) &&
+             render_area.offset.x == 0 && render_area.offset.y == 0 &&
+             render_area.extent.width == iview->image->extent.width &&
+             render_area.extent.height == iview->image->extent.height) {
+            /* We currently only support HiZ for single-layer images */
+            assert(iview->image->planes[0].aux_usage == ISL_AUX_USAGE_HIZ);
+            assert(iview->planes[0].isl.base_level == 0);
+            assert(iview->planes[0].isl.base_array_layer == 0);
+            assert(fb->layers == 1);
+
+            anv_image_hiz_clear(cmd_buffer, image,
+                                att_state->pending_clear_aspects,
+                                iview->planes[0].isl.base_level,
+                                0, 1, render_area,
+                                att_state->clear_value.depthStencil.stencil);
+
+            /* Performing a fast clear takes care of all our transition needs
+             * for the attachment.  Set clear_layer_count and layer_count to
+             * indicate that no clears or transitions need to be done.
+             */
+            clear_layer_count = 0;
+            layer_count = 0;
+         }
+      }
+
+      if (image->aspects & VK_IMAGE_ASPECT_ANY_COLOR_BIT_ANV) {
+         assert(image->aspects == VK_IMAGE_ASPECT_COLOR_BIT);
+
+         if (layer_count > 0) {
+            transition_color_buffer(cmd_buffer, image,
+                                    VK_IMAGE_ASPECT_COLOR_BIT,
+                                    iview->planes[0].isl.base_level, 1,
+                                    base_layer, layer_count,
+                                    att_state->current_layout, target_layout);
+         }
+      } else if (image->aspects & VK_IMAGE_ASPECT_DEPTH_BIT) {
+         if (layer_count > 0) {
+            transition_depth_buffer(cmd_buffer, image,
+                                    att_state->current_layout, target_layout);
+         }
+         att_state->aux_usage =
+            anv_layout_to_aux_usage(&cmd_buffer->device->info, image,
+                                    VK_IMAGE_ASPECT_DEPTH_BIT, target_layout);
+      }
+      att_state->current_layout = target_layout;
+
+      if (att_state->pending_clear_aspects & VK_IMAGE_ASPECT_COLOR_BIT) {
+         assert(att_state->pending_clear_aspects == VK_IMAGE_ASPECT_COLOR_BIT);
+
+         /* Multi-planar images are not supported as attachments */
+         assert(image->aspects == VK_IMAGE_ASPECT_COLOR_BIT);
+         assert(image->n_planes == 1);
+
          if (clear_layer_count > 0) {
             assert(image->n_planes == 1);
             anv_image_clear_color(cmd_buffer, image, VK_IMAGE_ASPECT_COLOR_BIT,
@@ -3520,30 +3562,32 @@ cmd_buffer_begin_subpass(struct anv_cmd_buffer *cmd_buffer,
          }
       } else if (att_state->pending_clear_aspects & (VK_IMAGE_ASPECT_DEPTH_BIT |
                                                      VK_IMAGE_ASPECT_STENCIL_BIT)) {
-         if (att_state->fast_clear) {
-            /* We currently only support HiZ for single-layer images */
-            if (att_state->pending_clear_aspects & VK_IMAGE_ASPECT_DEPTH_BIT) {
-               assert(iview->image->planes[0].aux_usage == ISL_AUX_USAGE_HIZ);
-               assert(iview->planes[0].isl.base_level == 0);
-               assert(iview->planes[0].isl.base_array_layer == 0);
-               assert(fb->layers == 1);
-            }
+         if (clear_layer_count > 0) {
+            if (att_state->fast_clear) {
+               /* We currently only support HiZ for single-layer images */
+               if (att_state->pending_clear_aspects & VK_IMAGE_ASPECT_DEPTH_BIT) {
+                  assert(iview->image->planes[0].aux_usage == ISL_AUX_USAGE_HIZ);
+                  assert(iview->planes[0].isl.base_level == 0);
+                  assert(iview->planes[0].isl.base_array_layer == 0);
+                  assert(fb->layers == 1);
+               }
 
-            anv_image_hiz_clear(cmd_buffer, image,
-                                att_state->pending_clear_aspects,
-                                iview->planes[0].isl.base_level,
-                                iview->planes[0].isl.base_array_layer,
-                                fb->layers, render_area,
-                                att_state->clear_value.depthStencil.stencil);
-         } else {
-            anv_image_clear_depth_stencil(cmd_buffer, image,
-                                          att_state->pending_clear_aspects,
-                                          att_state->aux_usage,
-                                          iview->planes[0].isl.base_level,
-                                          iview->planes[0].isl.base_array_layer,
-                                          fb->layers, render_area,
-                                          att_state->clear_value.depthStencil.depth,
-                                          att_state->clear_value.depthStencil.stencil);
+               anv_image_hiz_clear(cmd_buffer, image,
+                                   att_state->pending_clear_aspects,
+                                   iview->planes[0].isl.base_level,
+                                   base_clear_layer, clear_layer_count,
+                                   render_area,
+                                   att_state->clear_value.depthStencil.stencil);
+            } else {
+               anv_image_clear_depth_stencil(cmd_buffer, image,
+                                             att_state->pending_clear_aspects,
+                                             att_state->aux_usage,
+                                             iview->planes[0].isl.base_level,
+                                             base_clear_layer, clear_layer_count,
+                                             render_area,
+                                             att_state->clear_value.depthStencil.depth,
+                                             att_state->clear_value.depthStencil.stencil);
+            }
          }
       } else  {
          assert(att_state->pending_clear_aspects == 0);
-- 
2.5.0.400.gff86faf



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