add a tester for profiling event profiling queries

Author: bashbaug

samples/99_profbench/CMakeLists.txt

@@ -0,0 +1,10 @@
+# Copyright (c) 2026 Ben Ashbaugh
+#
+# SPDX-License-Identifier: MIT
+
+add_opencl_sample(
+    TEST
+    NUMBER 99
+    TARGET profbench
+    VERSION 120
+    SOURCES main.cpp)

samples/99_profbench/main.cpp

@@ -0,0 +1,133 @@
+/*
+// Copyright (c) 2026 Ben Ashbaugh
+//
+// SPDX-License-Identifier: MIT
+*/
+
+#include <popl/popl.hpp>
+#include <CL/opencl.hpp>
+#include <chrono>
+#include "util.hpp"
+
+static const char kernelString[] = R"CLC(
+kernel void inc_buffer(global int* dst)
+{
+    atomic_inc(dst);
+}
+)CLC";
+
+int main(
+    int argc,
+    char** argv )
+{
+    int platformIndex = 0;
+    int deviceIndex = 0;
+
+    size_t numEvents = 1024 * 1024;
+
+    {
+        popl::OptionParser op("Supported Options");
+        op.add<popl::Value<int>>("p", "platform", "Platform Index", platformIndex, &platformIndex);
+        op.add<popl::Value<int>>("d", "device", "Device Index", deviceIndex, &deviceIndex);
+        op.add<popl::Value<size_t>>("n", "numevents", "Number of Events", numEvents, &numEvents);
+
+        bool printUsage = false;
+        try {
+            op.parse(argc, argv);
+        } catch (std::exception& e) {
+            fprintf(stderr, "Error: %s\n\n", e.what());
+            printUsage = true;
+        }
+
+        if (printUsage || !op.unknown_options().empty() || !op.non_option_args().empty()) {
+            fprintf(stderr,
+                "Usage: profbench [options]\n"
+                "%s", op.help().c_str());
+            return -1;
+        }
+    }
+
+    std::vector<cl::Platform> platforms;
+    cl::Platform::get(&platforms);
+
+    if (!checkPlatformIndex(platforms, platformIndex)) {
+        return -1;
+    }
+
+    printf("Running on platform: %s\n",
+        platforms[platformIndex].getInfo<CL_PLATFORM_NAME>().c_str() );
+
+    std::vector<cl::Device> devices;
+    platforms[platformIndex].getDevices(CL_DEVICE_TYPE_ALL, &devices);
+
+    printf("Running on device: %s\n",
+        devices[deviceIndex].getInfo<CL_DEVICE_NAME>().c_str() );
+
+    cl::Context context{devices[deviceIndex]};
+    cl::CommandQueue commandQueue{context, devices[deviceIndex], CL_QUEUE_PROFILING_ENABLE};
+
+    cl::Program program{ context, kernelString };
+    program.build();
+    cl::Kernel kernel = cl::Kernel{ program, "inc_buffer" };
+
+    cl::Buffer buf = cl::Buffer{
+        context,
+        CL_MEM_ALLOC_HOST_PTR,
+        sizeof(cl_int) };
+
+    kernel.setArg(0, buf);
+
+    const cl_int zero = 0;
+    commandQueue.enqueueFillBuffer(buf, zero, 0, sizeof(zero));
+
+    std::vector<cl::Event>  events;
+    events.reserve(numEvents);
+
+    printf("Enqueueing kernels to create %zu events...\n", numEvents);
+    for (int i = 0; i < numEvents; i++) {
+        cl::Event event;
+        commandQueue.enqueueNDRangeKernel(
+            kernel,
+            cl::NullRange,
+            cl::NDRange{1},
+            cl::NullRange,
+            nullptr,
+            &event);
+        events.push_back(std::move(event));
+    }
+
+    printf("Waiting for %zu kernels to complete...\n", numEvents);
+    commandQueue.finish();
+
+    cl_ulong totalTimeNS = 0;
+    printf("Querying profiling data for %zu events...\n", numEvents);
+
+    auto start = std::chrono::system_clock::now();
+
+    for (const auto& event : events) {
+        totalTimeNS =
+            event.getProfilingInfo<CL_PROFILING_COMMAND_END>() -
+            event.getProfilingInfo<CL_PROFILING_COMMAND_START>();
+    }
+
+    auto end = std::chrono::system_clock::now();
+    std::chrono::duration<float> queryTimeS = end - start;
+    printf("Querying profiling data took %f s (%f us per event)\n",
+        queryTimeS.count(), queryTimeS.count() * 1000000 / numEvents);
+
+    int result = 0;
+    commandQueue.enqueueReadBuffer(
+        buf,
+        CL_TRUE,
+        0,
+        sizeof(result),
+        &result);
+
+    if (result == numEvents) {
+        printf("Success.\n");
+    } else {
+        printf("Unexpected result: %d\n", result);
+    }
+
+    return 0;
+}

samples/CMakeLists.txt

@@ -78,6 +78,8 @@ add_subdirectory( 06_ndrangekernelfromfile )
 add_subdirectory( 10_queueexperiments )
 add_subdirectory( 16_floatatomics )
 
+add_subdirectory( 99_profbench )
+
 set(BUILD_EXTENSION_SAMPLES TRUE)
 if(NOT TARGET OpenCLExt)
     message(STATUS "Skipping Extension Samples - OpenCL Extension Loader is not found.")