Increase GPU limits to unconstrain size of resources that can be used

Author: Nelarius

notes/storage_buffer_binding_size.md

@@ -1,5 +1,13 @@
 # `.maxStorageBufferBindingSize`
 
+_Amended: 2024-04-07_
+
+> Dawn's internal storage buffer limit is 256 MiB, or `1 << 28` bytes.
+
+The default max buffer size is 256 MiB. Increasing the max storage buffer binding size alone has not effect, as it is constrained by the max buffer size. Setting `maxBufferSize` > $2^{28}$ bytes unconstrains the storage buffer limit again. At the time of writing, the `maxBufferSize` was 10 GiB on both macOS and Windows.
+
+The storage buffer binding size limit is the one which validation triggers when creating buffers larger than the limit, hence the initial focus on this particular value.
+
 _Written: 2023-11-10_
 
 _Context: when doing texture lookup on the GPU for the first time, it was observed that a single texture buffer can exceed Dawn's internal storage buffer size limit._

src/pt/gpu_limits.hpp

@@ -0,0 +1,39 @@
+#pragma once
+
+namespace nlrs
+{
+constexpr WGPULimits REQUIRED_LIMITS{
+    .maxTextureDimension1D = 0,
+    .maxTextureDimension2D = 0,
+    .maxTextureDimension3D = 0,
+    .maxTextureArrayLayers = 0,
+    .maxBindGroups = 4,
+    .maxBindGroupsPlusVertexBuffers = 0,
+    .maxBindingsPerBindGroup = 8,
+    .maxDynamicUniformBuffersPerPipelineLayout = 0,
+    .maxDynamicStorageBuffersPerPipelineLayout = 0,
+    .maxSampledTexturesPerShaderStage = 0,
+    .maxSamplersPerShaderStage = 0,
+    .maxStorageBuffersPerShaderStage = 8,
+    .maxStorageTexturesPerShaderStage = 0,
+    .maxUniformBuffersPerShaderStage = 1,
+    .maxUniformBufferBindingSize = 1 << 10,
+    .maxStorageBufferBindingSize = 1 << 30,
+    .minUniformBufferOffsetAlignment = 256,
+    .minStorageBufferOffsetAlignment = 256,
+    .maxVertexBuffers = 4,
+    .maxBufferSize = 1 << 30,
+    .maxVertexAttributes = 8,
+    .maxVertexBufferArrayStride = sizeof(float[4]),
+    .maxInterStageShaderComponents = 0,
+    .maxInterStageShaderVariables = 0,
+    .maxColorAttachments = 4,
+    .maxColorAttachmentBytesPerSample = 0,
+    .maxComputeWorkgroupStorageSize = 0,
+    .maxComputeInvocationsPerWorkgroup = 0,
+    .maxComputeWorkgroupSizeX = 0,
+    .maxComputeWorkgroupSizeY = 0,
+    .maxComputeWorkgroupSizeZ = 0,
+    .maxComputeWorkgroupsPerDimension = 0,
+};
+}

src/pt/main.cpp

@@ -1,5 +1,6 @@
 #include "fly_camera_controller.hpp"
 #include "gpu_context.hpp"
+#include "gpu_limits.hpp"
 #include "gui.hpp"
 #include "deferred_renderer.hpp"
 #include "reference_path_tracer.hpp"
@@ -112,11 +113,12 @@ try
         return 0;
     }
 
-    nlrs::GpuContext gpuContext{nlrs::ReferencePathTracer::wgpuRequiredLimits};
-    nlrs::Window     window = [&gpuContext]() -> nlrs::Window {
+    nlrs::GpuContext gpuContext{
+        WGPURequiredLimits{.nextInChain = nullptr, .limits = nlrs::REQUIRED_LIMITS}};
+    nlrs::Window window = [&gpuContext]() -> nlrs::Window {
         const nlrs::WindowDescriptor windowDesc{
-                .windowSize = nlrs::Extent2i{defaultWindowWidth, defaultWindowHeight},
-                .title = "pt-playground 🛝",
+            .windowSize = nlrs::Extent2i{defaultWindowWidth, defaultWindowHeight},
+            .title = "pt-playground 🛝",
         };
         return nlrs::Window{windowDesc, gpuContext};
     }();

src/pt/reference_path_tracer.cpp

@@ -1,5 +1,6 @@
 #include "gpu_bind_group_layout.hpp"
 #include "gpu_context.hpp"
+#include "gpu_limits.hpp"
 #include "reference_path_tracer.hpp"
 #include "shader_source.hpp"
 #include "webgpu_utils.hpp"
@@ -231,7 +232,7 @@ ReferencePathTracer::ReferencePathTracer(
 
         const std::size_t textureDataNumBytes = textureData.size() * sizeof(Texture::BgraPixel);
         const std::size_t maxStorageBufferBindingSize =
-            static_cast<std::size_t>(wgpuRequiredLimits.limits.maxStorageBufferBindingSize);
+            static_cast<std::size_t>(REQUIRED_LIMITS.maxStorageBufferBindingSize);
         if (textureDataNumBytes > maxStorageBufferBindingSize)
         {
             throw std::runtime_error(fmt::format(

src/pt/reference_path_tracer.hpp

@@ -74,45 +74,6 @@ class ReferencePathTracer
     float averageRenderpassDurationMs() const;
     float renderProgressPercentage() const;
 
-    static constexpr WGPURequiredLimits wgpuRequiredLimits{
-        .nextInChain = nullptr,
-        .limits =
-            WGPULimits{
-                .maxTextureDimension1D = 0,
-                .maxTextureDimension2D = 0,
-                .maxTextureDimension3D = 0,
-                .maxTextureArrayLayers = 0,
-                .maxBindGroups = 2,
-                .maxBindGroupsPlusVertexBuffers = 0,
-                .maxBindingsPerBindGroup = 7,
-                .maxDynamicUniformBuffersPerPipelineLayout = 0,
-                .maxDynamicStorageBuffersPerPipelineLayout = 0,
-                .maxSampledTexturesPerShaderStage = 0,
-                .maxSamplersPerShaderStage = 0,
-                .maxStorageBuffersPerShaderStage = 6,
-                .maxStorageTexturesPerShaderStage = 0,
-                .maxUniformBuffersPerShaderStage = 1,
-                .maxUniformBufferBindingSize = 80,
-                .maxStorageBufferBindingSize = 1 << 28, // 256 MiB
-                .minUniformBufferOffsetAlignment = 256,
-                .minStorageBufferOffsetAlignment = 256,
-                .maxVertexBuffers = 1,
-                .maxBufferSize = 0,
-                .maxVertexAttributes = 2,
-                .maxVertexBufferArrayStride = 2 * sizeof(float),
-                .maxInterStageShaderComponents = 0,
-                .maxInterStageShaderVariables = 0,
-                .maxColorAttachments = 0,
-                .maxColorAttachmentBytesPerSample = 0,
-                .maxComputeWorkgroupStorageSize = 0,
-                .maxComputeInvocationsPerWorkgroup = 0,
-                .maxComputeWorkgroupSizeX = 0,
-                .maxComputeWorkgroupSizeY = 0,
-                .maxComputeWorkgroupSizeZ = 0,
-                .maxComputeWorkgroupsPerDimension = 0,
-            },
-    };
-
 private:
     GpuBuffer          mVertexBuffer;
     GpuBuffer          mRenderParamsBuffer;