graphics: reuse texture conversion scratch buffers across uploads

src/graphics/host_gpu/renderer/cache/textureCache.cpp

@@ -583,7 +583,7 @@ bool TextureCache::CopyD16(Image& destination, Image& source) {
 	}
 
 	auto                         depth_buffer = m_tiler.GetScratchBuffer(depth_size);
-	auto                         color_buffer = m_tiler.GetScratchBuffer(color_size);
+	auto                         color_buffer = m_tiler.GetScratchBuffer(color_size, depth_buffer.buffer);
 	const TileManager::D16Layout promote_layout {
 	    .width               = depth.info.extent.width,
 	    .height              = depth.info.extent.height,
@@ -1071,7 +1071,7 @@ void TextureCache::UploadImage(Image& image, Buffer& source, uint64_t source_off
 		                     texels_per_slice > UINT64_MAX / transfer_bytes);
 		const uint64_t transfer_slice = texels_per_slice * transfer_bytes;
 		EXIT_NOT_IMPLEMENTED(transfer_slice > UINT64_MAX / layers);
-		auto promoted = m_tiler.GetScratchBuffer(transfer_slice * layers);
+		auto promoted = m_tiler.GetScratchBuffer(transfer_slice * layers, linear.buffer);
 		m_tiler.ConvertD16(
 		    linear, promoted, TileManager::D16Direction::Promote,
 		    info.pixel_format == vk::Format::eD32SfloatS8Uint,
@@ -1679,7 +1679,7 @@ void TextureCache::DownloadDepth(Image& image, Buffer& destination, uint64_t des
 	auto host_linear = m_tiler.GetScratchBuffer(transfer_size);
 	image.Download(copies, host_linear.buffer, 0, host_linear.size);
 	const bool tiled        = info.IsTiled();
-	auto       guest_linear = tiled ? m_tiler.GetScratchBuffer(info.data.size)
+	auto       guest_linear = tiled ? m_tiler.GetScratchBuffer(info.data.size, host_linear.buffer)
 	                                : TileManager::Result {destination.Handle(), destination_offset,
 	                                                       destination.Size() - destination_offset};
 	m_tiler.ConvertD16(host_linear, guest_linear, TileManager::D16Direction::Demote,

src/graphics/host_gpu/renderer/image/tiler.cpp

@@ -88,30 +88,6 @@ TileManager::~TileManager() {
 	}
 }
 
-TileManager::Scratch TileManager::AllocateScratch(uint64_t size) {
-	EXIT_IF(size == 0);
-	vk::BufferCreateInfo create {};
-	create.size  = size;
-	create.usage = vk::BufferUsageFlagBits::eStorageBuffer | vk::BufferUsageFlagBits::eTransferSrc |
-	               vk::BufferUsageFlagBits::eTransferDst;
-
-	VmaAllocationCreateInfo allocate {};
-	allocate.usage       = VMA_MEMORY_USAGE_AUTO_PREFER_DEVICE;
-	VkBuffer      buffer = VK_NULL_HANDLE;
-	VmaAllocation memory = nullptr;
-	const auto    raw    = static_cast<VkBufferCreateInfo>(create);
-	RequireVulkanSuccess(static_cast<vk::Result>(vmaCreateBuffer(
-	                         m_graphics.allocator, &raw, &allocate, &buffer, &memory, nullptr)),
-	                     "allocate TileManager scratch buffer");
-	return {buffer, memory, size};
-}
-
-void TileManager::DeferDestroy(Scratch scratch) {
-	auto allocator = m_graphics.allocator;
-	m_scheduler.DeferOperation(
-	    [allocator, scratch] { vmaDestroyBuffer(allocator, scratch.buffer, scratch.allocation); });
-}
-
 void TileManager::Prepare(bool tile, uint64_t tiled_capacity, uint64_t linear_capacity,
                           std::span<const GpuTileInfo> infos, uint64_t source_base,
                           uint64_t target_base, std::vector<Dispatch>& dispatches) {
@@ -369,8 +345,7 @@ TileManager::Result TileManager::Detile(vk::Buffer tiled, uint64_t tiled_offset,
 	const uint64_t        source_base = tiled_offset & (descriptor_alignment - 1);
 	std::vector<Dispatch> dispatches;
 	Prepare(false, tiled_capacity, linear_capacity, infos, source_base, 0, dispatches);
-	auto scratch = AllocateScratch(Common::AlignUp(linear_capacity, 4));
+	auto scratch = GetScratchBuffer(linear_capacity, tiled);
-	DeferDestroy(scratch);
 	Record(tiled, tiled_offset, tiled_capacity, scratch.buffer, 0, scratch.size, dispatches,
 	       true);
 	return {scratch.buffer, 0, linear_capacity};
@@ -400,11 +375,9 @@ void TileManager::TileImage(Image& image, std::span<const vk::BufferImageCopy> r
 	    std::max<uint64_t>(limits.minStorageBufferOffsetAlignment, 4);
 	const uint64_t        target_base = tiled_offset & (descriptor_alignment - 1);
 	std::vector<Dispatch> dispatches;
-	// Reserve all stream parameters before creating a scheduler-lived scratch dependency:
+	// Reserve stream parameters before recording the image download and conversion.
-	// StreamBuffer::Map is allowed to submit the current tick when it wraps.
 	Prepare(true, tiled_capacity, linear_capacity, infos, 0, target_base, dispatches);
-	auto linear = AllocateScratch(Common::AlignUp(linear_capacity, 4));
+	auto linear = GetScratchBuffer(linear_capacity, tiled);
-	DeferDestroy(linear);
 	image.Download(regions, linear.buffer, 0, linear.size);
 	Result source {linear.buffer, 0, linear.size};
 	if (transform == ColorTransform::SwapBgra16) {
@@ -414,10 +387,19 @@ void TileManager::TileImage(Image& image, std::span<const vk::BufferImageCopy> r
 	       dispatches, false);
 }
 
-TileManager::Result TileManager::GetScratchBuffer(uint64_t size) {
+TileManager::Result TileManager::GetScratchBuffer(uint64_t size, vk::Buffer input) {
-	auto scratch = AllocateScratch(Common::AlignUp(size, 4));
+	EXIT_IF(size == 0);
-	DeferDestroy(scratch);
+	size = Common::AlignUp(size, 4);
-	return {scratch.buffer, 0, scratch.size};
+	auto& buffer = m_scratch[m_scratch[0] && m_scratch[0]->Handle() == input ? 1 : 0];
+	if (!buffer || buffer->Size() < size) {
+		if (buffer) {
+			m_scheduler.DeferOperation([old = std::move(buffer)]() mutable { old.reset(); });
+		}
+		buffer = std::make_unique<Buffer>(m_graphics, m_scheduler, MemoryUsage::DeviceLocal, 0,
+		    vk::BufferUsageFlagBits::eStorageBuffer | vk::BufferUsageFlagBits::eTransferSrc |
+		        vk::BufferUsageFlagBits::eTransferDst, size);
+	}
+	return {buffer->Handle(), 0, size};
 }
 
 TileManager::StorageBinding TileManager::BindStorage(Result buffer, uint64_t size) const {
@@ -668,9 +650,7 @@ void TileManager::SwapBgra16(Result input, Result output, uint32_t pixels) {
 
 TileManager::Result TileManager::SwapBgra16(Result input) {
 	EXIT_NOT_IMPLEMENTED(input.size == 0 || input.size % 8u != 0 || input.size / 8u > UINT32_MAX);
-	auto output = AllocateScratch(input.size);
+	auto result = GetScratchBuffer(input.size, input.buffer);
-	DeferDestroy(output);
-	Result result {output.buffer, 0, output.size};
 	SwapBgra16(input, result, static_cast<uint32_t>(input.size / 8u));
 	return result;
 }

src/graphics/host_gpu/renderer/image/tiler.h

@@ -6,13 +6,14 @@
 #include "graphics/host_gpu/vulkanCommon.h"
 
 #include <array>
+#include <memory>
 #include <span>
 #include <vector>
-#include <vk_mem_alloc.h>
 
 namespace Libs::Graphics {
 
 class CommandScheduler;
+class Buffer;
 class Image;
 class StreamBuffer;
 struct GraphicContext;
@@ -62,7 +63,7 @@ public:
 	~TileManager();
 	KYTY_CLASS_NO_COPY(TileManager);
 
-	// The returned device-local buffer remains alive through the current scheduler tick.
+	// Consume scratch results before the next acquisition, or pass their buffer as input.
 	[[nodiscard]] Result Detile(vk::Buffer tiled, uint64_t tiled_offset, uint64_t tiled_capacity,
 	                            uint64_t linear_capacity, std::span<const GpuTileInfo> infos);
 	void Tile(vk::Buffer linear, uint64_t linear_offset, uint64_t linear_capacity, vk::Buffer tiled,
@@ -71,7 +72,7 @@ public:
 	               uint64_t tiled_offset, uint64_t tiled_capacity, uint64_t linear_capacity,
 	               std::span<const GpuTileInfo> infos,
 	               ColorTransform               transform = ColorTransform::None);
-	[[nodiscard]] Result GetScratchBuffer(uint64_t size);
+	[[nodiscard]] Result GetScratchBuffer(uint64_t size, vk::Buffer input = nullptr);
 	void                 ConvertD16(Result source, Result target, D16Direction direction, bool d32,
 	                                const D16Layout& layout);
 	[[nodiscard]] Result SwapBgra16(Result input);
@@ -105,23 +106,16 @@ private:
 		uint32_t pipeline_slot = 0;
 		uint64_t params_offset = 0;
 	};
-	struct Scratch {
-		vk::Buffer    buffer     = nullptr;
-		VmaAllocation allocation = nullptr;
-		uint64_t      size       = 0;
-	};
 	struct StorageBinding {
 		vk::DescriptorBufferInfo info;
 		uint32_t                 base = 0;
 	};
 
-	[[nodiscard]] Scratch         AllocateScratch(uint64_t size);
 	[[nodiscard]] StorageBinding  BindStorage(Result buffer, uint64_t size) const;
 	[[nodiscard]] static uint32_t ConversionRows(uint64_t offset, uint64_t row_stride,
 	                                             uint64_t active, uint32_t remaining,
 	                                             uint64_t alignment, uint64_t max_range,
 	                                             uint32_t max_groups) noexcept;
-	void                          DeferDestroy(Scratch scratch);
 	void Prepare(bool tile, uint64_t tiled_capacity, uint64_t linear_capacity,
 	             std::span<const GpuTileInfo> infos, uint64_t source_base, uint64_t target_base,
 	             std::vector<Dispatch>& dispatches);
@@ -134,6 +128,7 @@ private:
 	GraphicContext&                         m_graphics;
 	CommandScheduler&                       m_scheduler;
 	StreamBuffer&                           m_stream_buffer;
+	std::array<std::unique_ptr<Buffer>, 2>   m_scratch;
 	vk::DescriptorSetLayout                 m_descriptor_layout = nullptr;
 	vk::PipelineLayout                      m_pipeline_layout   = nullptr;
 	std::array<vk::Pipeline, PipelineCount> m_pipelines {};

tests/ShaderRecompilerComputeTests.cpp

@@ -15298,6 +15298,40 @@ public:
           source_stage, vk::PipelineStageFlagBits::eHost, {}, 0, nullptr, 1,
           &barrier, 0, nullptr);
     };
+    auto scratch_input = CreateHostBuffer(name, 32, AllFlags,
+        {0x00020001u, 0x00040003u, 0x00060005u, 0x00080007u,
+         0x000a0009u, 0x000c000bu, 0x000e000du, 0x0010000fu});
+    auto scratch_output = CreateHostBuffer(name, 56, AllFlags, {});
+    const auto copy_scratch = [&](TileManager::Result result, uint64_t offset) {
+      const vk::BufferCopy copy{result.offset, offset, result.size};
+      scheduler.Current().Handle().copyBuffer(result.buffer, scratch_output.buffer, 1, &copy);
+    };
+    // Keep all four conversions in flight to check growth, overwrite ordering,
+    // the requested span on reuse, and two simultaneously live workspaces.
+    const auto first = tile_manager.SwapBgra16({scratch_input.buffer, 0, 8});
+    copy_scratch(first, 0);
+    const auto grown = tile_manager.SwapBgra16({scratch_input.buffer, 0, 32});
+    copy_scratch(grown, 8);
+    const auto reused = tile_manager.SwapBgra16({scratch_input.buffer, 8, 8});
+    copy_scratch(reused, 40);
+    const auto paired = tile_manager.SwapBgra16(reused);
+    copy_scratch(paired, 48);
+    Require(name, "scratch workspace reuse",
+            first.buffer != grown.buffer && grown.buffer == reused.buffer &&
+                reused.buffer != paired.buffer && reused.size == 8 && paired.size == 8,
+            "scratch growth, input exclusion, or requested span was lost");
+    host_barrier(scratch_output.buffer, scratch_output.size,
+                    vk::PipelineStageFlagBits::eTransfer, vk::AccessFlagBits::eTransferWrite);
+    scheduler.Finish();
+    Require(name, "scratch workspace GPU contents",
+            ReadBuffer(name, scratch_output, 14) == std::vector<u32>{
+                0x00020003u, 0x00040001u,
+                0x00020003u, 0x00040001u, 0x00060007u, 0x00080005u,
+                0x000a000bu, 0x000c0009u, 0x000e000fu, 0x0010000du,
+                0x00060007u, 0x00080005u, 0x00060005u, 0x00080007u},
+            "scratch reuse overwrote an earlier result or its live conversion input");
+    DestroyBuffer(&scratch_output);
+    DestroyBuffer(&scratch_input);
     const auto gpu_detile =
         [&](const std::vector<uint8_t> &tiled, std::vector<uint8_t> *linear,
             uint64_t tiled_capacity, uint64_t linear_capacity,