例如,在内核启动之前,可能会对输入缓冲区进行CPU缓存刷新。 CPU缓存操作有一个极其容易被测量的开销值,即CL_PROFILING_COMMAND_QUEUED和CL_PROFILING_COMMAND_SUBMIT之间的增量,如图4-1所示。在某些情况下,clEnqueueMapBuffer/Image和clEnqueueUnmapBuffer/Image的执行时间会增加。CPU缓存操作的成本通常随内存对象大小而线...
clWaitForEvents(1, &timing_event); clGetEventProfilingInfo(timing_event, CL_PROFILING_COMMAND_QUEUED, sizeof(cl_ulong), &t_queued, nullptr); clGetEventProfilingInfo(timing_event, CL_PROFILING_COMMAND_SUBMIT, sizeof(cl_ulong), &t_submit, nullptr); clGetEventProfilingInfo(timing_event, CL_PROFI...
void PrintProfilingInfo(cl_event event) { cl_ulong t_queued; cl_ulong t_submitted; cl_ulong t_started; cl_ulong t_ended; cl_ulong t_completed; clGetEventProfilingInfo(event, CL_PROFILING_COMMAND_QUEUED, sizeof(cl_ulong), &t_queued, NULL); clGetEventProfilingInfo(event, CL_PROFILING_COMM...
使用了类似的代码来做android下opencl的时间测试: cl::CommandQueue queue(context, devices[0],CL_QUEUE_PROFILING_ENABLE, &err); cl::Event event; //... event.wait(); // cl_ulong startTime=0, endTime=0, queued=0, submit=0; event.getProfilingInfo(CL_PROFILING_COMMAND_START, &startTime);...
CPU cache操作会有可以测量的损失,可以通过clEnqueueNDRangeKernel中的CL_PROFILING_COMMAND_QUEUED与CL_PROFILING_COMMAND_SUBMIT之间的差值查看,如图4-1显示的那样。在某些情况下,clEnqueueMapBuffer/Image和clEnqueueUnmapBuffer/Image的执行时间可能会增加。一个CPU cache操作的耗时通常会随着内存对象的大小线性增加。
对于clEnqueeNDRangeKernel调用,使用clGetEventProfilingInfo函数和四个分析参数,包括CL_PROFILING_COMMAND_(QUEUED, SUBMIT, START,and END),可以在Adreno GPU中提供内核启动延迟和内核执行时间的准确图片。如下图所示: 三、总结 本篇文章介绍了Adreno OpenCL应用程序开发过程中的CPU和GPU定时器相关内容,大家对此部分内容...
These overheads are measured in uCLBench using the OpenCL profiling event mechanism – we define the invoca- tion overhead as the elapsed time between the CL PROFILING COMMAND QUEUED and CL PROFILING COMMAND START events, and the compilation time as the time spent in the clBuildProgram call. ...
Important difference between OpenCL events profiling method and host-based time difference method: OpenCL events profiling method provides distinct measurements for each stage of the OpenCL pipeline: CL_PROFILING_COMMAND_QUEUED CL_PROFILING_COMMAND_SUBMIT CL_PROFILING_COMMAND_START CL_...
void Event::FillTimingInfo(const int idx) { int sidx, eidx; if (idx == ALL_EVENTS) { sidx = 0; eidx = count-1; } else sidx = eidx = idx; for (int i=sidx ; i<=eidx ; ++i) { cl_int err; err = clGetEventProfilingInfo(event, CL_PROFILING_COMMAND_QUEUED, sizeof(cl_ul...
OpenCL provides four timestamps: • CL_PROFILING_COMMAND_QUEUED - Indicates when the command is enqueued into a command-queue on the host. This is set by the OpenCL runtime when the user calls an clEnqueue* function. • CL_PROFILING_COMMAND_SUBMIT - Indicates when the command is ...