wehub-resource-sync
33 lines
1.4 KiB
Markdown
33 lines
1.4 KiB
Markdown
# libnd4j CUDA Kernel Launch Configuration
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This part of the libnd4j codebase provides a centralized way to handle CUDA launch configurations. It allows customization of launch dimensions using environment variables.
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## Conceptual Overview
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The code sets up CUDA launch configurations for a wide range of algorithms used in the libnd4j codebase. These configurations are expressed as `dim3` structures, representing grid and block dimensions for launching CUDA kernels. The configurations are stored in a map, improving performance via a caching mechanism.
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### Key Feature
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A significant feature of this code is the flexibility it offers, allowing users to specify custom launch dimensions through environment variables. This enables modifications of these configurations at both compile-time and runtime.
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## Examples of Usage
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```cpp
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// Fetching Launch Dimensions
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dim3 launchDims = getLaunchDims("matrixMultiply");
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//invoke your cuda function
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yourKernel<<<launchDims.y,launchDims.x,launchDims.z>>>
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//This returns the blocks, threads and shared memory used for the kernel.
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```
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The launch configuration can be found in
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```bash
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../include/execution/cuda/LaunchDims.h
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../include/execution/cuda/LaunchDims.cu
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```
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Every kernel has environment variables that work at build time and runtime.
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Build time is used to modify defaults. Runtime is used to override buildtime and defaults.
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