Swati Rawat
90 líneas
2.8 KiB
ReStructuredText
90 líneas
2.8 KiB
ReStructuredText
.. meta::
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:description: Documentation for using rocprofv3 with OpenMP applications
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:keywords: ROCprofiler-SDK tool, OpenMP, rocprofv3, rocprofv3 tool usage, ROCprofiler-SDK command line tool, ROCprofiler-SDK CLI
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.. _using-rocprofv3-with-openmp:
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Using rocprofv3 with OpenMP
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+++++++++++++++++++++++++++++
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For computations offloaded to AMD GPUs using OpenMP (for example, via OpenMP target offload), ``rocprofv3`` can be used to capture and profile GPU activities initiated by these offloaded regions. Note that ``rocprofv3`` doesn't provide native support for profiling CPU-side OpenMP code or parallel regions.
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Example: Vector addition using OpenMP offload on AMD GPUs
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----------------------------------------------------------
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The following example demonstrates how to perform vector addition using OpenMP target offload, enabling workload execution on AMD GPUs.
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**Key steps:**
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- Initialize input arrays on the host.
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- Offload the vector addition computation to the GPU using OpenMP directives.
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- Retrieve and verify the results on the host.
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.. code-block:: c
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#include <stdio.h>
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#include <omp.h>
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#define N 1024
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int main() {
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float a[N], b[N], c[N];
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// Initialize input arrays
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for (int i = 0; i < N; ++i) {
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a[i] = i * 1.0f;
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b[i] = (N - i) * 1.0f;
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}
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// Offload vector addition to GPU
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#pragma omp target teams distribute parallel for map(to: a[0:N], b[0:N]) map(from: c[0:N])
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for (int i = 0; i < N; ++i) {
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c[i] = a[i] + b[i];
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}
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// Verify results
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int errors = 0;
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for (int i = 0; i < N; ++i) {
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if (c[i] != N * 1.0f) {
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errors++;
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}
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}
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if (errors == 0) {
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printf("Vector addition successful!\\n");
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} else {
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printf("Vector addition failed with %d errors.\\n", errors);
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}
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return 0;
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}
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Building the OpenMP offload application
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----------------------------------------
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To compile the application for AMD GPU offload, use the following command:
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.. code-block:: bash
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amdclang++ -fopenmp -fopenmp-targets=amdgcn-amd-amdhsa -L/opt/rocm/lib --offload-arch=gfx9xx -o vector_add <application>
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Profiling the application with rocprofv3
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-----------------------------------------
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To profile the GPU activity during execution, run the application with ``rocprofv3``:
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.. code-block:: bash
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rocprofv3 -s --output-format csv -- ./vector_add
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Upon execution, ``rocprofv3`` generates several CSV trace files, such as:
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- <pid>_kernel_trace.csv
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- <pid>_hsa_api_trace.csv
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- <pid>_memory_copy_trace.csv
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- <pid>_memory_allocation_trace.csv
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- <pid>_scratch_memory_trace.csv
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The preceding files contain detailed profiling information about GPU kernel execution, HSA API calls, memory operations, and more, enabling comprehensive analysis of the offloaded workload.
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