radv: Use an array to store descriptor sets.

The vram_list linked list resulted in lots of pointer chasing.
Replacing this with an array instead improves descriptor set
allocation CPU usage by 3x at least (when also considering the free),
because it had to iterate through 300-400 sets on average.

Not a huge improvement as the pre-improvement CPU usage was only
about 2.3% in the busiest thread.

Reviewed-by: Dave Airlie <[email protected]>

2 files changed, 50 insertions, 26 deletions

diff --git a/src/amd/vulkan/radv_descriptor_set.c b/src/amd/vulkan/radv_descriptor_set.c
index 167944f4e2f..317a2b37c43 100644
--- a/src/amd/vulkan/radv_descriptor_set.c
+++ b/src/amd/vulkan/radv_descriptor_set.c
@@ -295,6 +295,11 @@ radv_descriptor_set_create(struct radv_device *device,
 		uint32_t layout_size = align_u32(layout->size, 32);
 		set->size = layout->size;
 
+		if (!pool->host_memory_base && pool->entry_count == pool->max_entry_count) {
+			vk_free2(&device->alloc, NULL, set);
+			return vk_error(VK_ERROR_OUT_OF_POOL_MEMORY_KHR);
+		}
+
 		/* try to allocate linearly first, so that we don't spend
 		 * time looking for gaps if the app only allocates &
 		 * resets via the pool. */
@@ -302,21 +307,21 @@ radv_descriptor_set_create(struct radv_device *device,
 			set->bo = pool->bo;
 			set->mapped_ptr = (uint32_t*)(pool->mapped_ptr + pool->current_offset);
 			set->va = radv_buffer_get_va(set->bo) + pool->current_offset;
+			if (!pool->host_memory_base) {
+				pool->entries[pool->entry_count].offset = pool->current_offset;
+				pool->entries[pool->entry_count].size = layout_size;
+				pool->entries[pool->entry_count].set = set;
+				pool->entry_count++;
+			}
 			pool->current_offset += layout_size;
-			list_addtail(&set->vram_list, &pool->vram_list);
 		} else if (!pool->host_memory_base) {
 			uint64_t offset = 0;
-			struct list_head *prev = &pool->vram_list;
-			struct radv_descriptor_set *cur;
+			int index;
 
-			assert(!pool->host_memory_base);
-			LIST_FOR_EACH_ENTRY(cur, &pool->vram_list, vram_list) {
-				uint64_t start = (uint8_t*)cur->mapped_ptr - pool->mapped_ptr;
-				if (start - offset >= layout_size)
+			for (index = 0; index < pool->entry_count; ++index) {
+				if (pool->entries[index].offset - offset >= layout_size)
 					break;
-
-				offset = start + cur->size;
-				prev = &cur->vram_list;
+				offset = pool->entries[index].offset + pool->entries[index].size;
 			}
 
 			if (pool->size - offset < layout_size) {
@@ -326,7 +331,12 @@ radv_descriptor_set_create(struct radv_device *device,
 			set->bo = pool->bo;
 			set->mapped_ptr = (uint32_t*)(pool->mapped_ptr + offset);
 			set->va = radv_buffer_get_va(set->bo) + offset;
-			list_add(&set->vram_list, prev);
+			memmove(&pool->entries[index + 1], &pool->entries[index],
+				sizeof(pool->entries[0]) * (pool->entry_count - index));
+			pool->entries[index].offset = offset;
+			pool->entries[index].size = layout_size;
+			pool->entries[index].set = set;
+			pool->entry_count++;
 		} else
 			return vk_error(VK_ERROR_OUT_OF_POOL_MEMORY_KHR);
 	}
@@ -361,8 +371,17 @@ radv_descriptor_set_destroy(struct radv_device *device,
 {
 	assert(!pool->host_memory_base);
 
-	if (free_bo && set->size)
-		list_del(&set->vram_list);
+	if (free_bo && set->size && !pool->host_memory_base) {
+		uint32_t offset = (uint8_t*)set->mapped_ptr - pool->mapped_ptr;
+		for (int i = 0; i < pool->entry_count; ++i) {
+			if (pool->entries[i].offset == offset) {
+				memmove(&pool->entries[i], &pool->entries[i+1],
+					sizeof(pool->entries[i]) * (pool->entry_count - i - 1));
+				--pool->entry_count;
+				break;
+			}
+		}
+	}
 	vk_free2(&device->alloc, NULL, set);
 }
 
@@ -414,6 +433,8 @@ VkResult radv_CreateDescriptorPool(
 		host_size += sizeof(struct radeon_winsys_bo*) * bo_count;
 		host_size += sizeof(struct radv_descriptor_range) * range_count;
 		size += host_size;
+	} else {
+		size += sizeof(struct radv_descriptor_pool_entry) * pCreateInfo->maxSets;
 	}
 
 	pool = vk_alloc2(&device->alloc, pAllocator, size, 8,
@@ -435,8 +456,8 @@ VkResult radv_CreateDescriptorPool(
 		pool->mapped_ptr = (uint8_t*)device->ws->buffer_map(pool->bo);
 	}
 	pool->size = bo_size;
+	pool->max_entry_count = pCreateInfo->maxSets;
 
-	list_inithead(&pool->vram_list);
 	*pDescriptorPool = radv_descriptor_pool_to_handle(pool);
 	return VK_SUCCESS;
 }
@@ -453,9 +474,8 @@ void radv_DestroyDescriptorPool(
 		return;
 
 	if (!pool->host_memory_base) {
-		list_for_each_entry_safe(struct radv_descriptor_set, set,
-		                         &pool->vram_list, vram_list) {
-			radv_descriptor_set_destroy(device, pool, set, false);
+		for(int i = 0; i < pool->entry_count; ++i) {
+			radv_descriptor_set_destroy(device, pool, pool->entries[i].set, false);
 		}
 	}
 
@@ -473,14 +493,12 @@ VkResult radv_ResetDescriptorPool(
 	RADV_FROM_HANDLE(radv_descriptor_pool, pool, descriptorPool);
 
 	if (!pool->host_memory_base) {
-		list_for_each_entry_safe(struct radv_descriptor_set, set,
-		                         &pool->vram_list, vram_list) {
-			radv_descriptor_set_destroy(device, pool, set, false);
+		for(int i = 0; i < pool->entry_count; ++i) {
+			radv_descriptor_set_destroy(device, pool, pool->entries[i].set, false);
 		}
+		pool->entry_count = 0;
 	}
 
-	list_inithead(&pool->vram_list);
-
 	pool->current_offset = 0;
 	pool->host_memory_ptr = pool->host_memory_base;
 
diff --git a/src/amd/vulkan/radv_private.h b/src/amd/vulkan/radv_private.h
index 83965b41b27..51bdde20323 100644
--- a/src/amd/vulkan/radv_private.h
+++ b/src/amd/vulkan/radv_private.h
@@ -612,8 +612,6 @@ struct radv_descriptor_set {
 	uint32_t *mapped_ptr;
 	struct radv_descriptor_range *dynamic_descriptors;
 
-	struct list_head vram_list;
-
 	struct radeon_winsys_bo *descriptors[0];
 };
 
@@ -623,17 +621,25 @@ struct radv_push_descriptor_set
 	uint32_t capacity;
 };
 
+struct radv_descriptor_pool_entry {
+	uint32_t offset;
+	uint32_t size;
+	struct radv_descriptor_set *set;
+};
+
 struct radv_descriptor_pool {
 	struct radeon_winsys_bo *bo;
 	uint8_t *mapped_ptr;
 	uint64_t current_offset;
 	uint64_t size;
 
-	struct list_head vram_list;
-
 	uint8_t *host_memory_base;
 	uint8_t *host_memory_ptr;
 	uint8_t *host_memory_end;
+
+	uint32_t entry_count;
+	uint32_t max_entry_count;
+	struct radv_descriptor_pool_entry entries[0];
 };
 
 struct radv_descriptor_update_template_entry {