2013-02-17 190 views
0

当使用clSetKernelArg(memory_object)设置内核参数并使用clEnqueueNDKernelRangeKernel()多次调用内核时,您以前在内核的clSetKernelArg()中将参数设置为的memory_object是从主机传输到GPU,每次调用内核?opencl中的多个内核调用

status = clSetKernelArg(kernel, 0, sizeof(cl_mem), &inbuf); 



    size_t num_total_wi = M * N; 
    size_t num_wg = num_elem/N + ((num_elem/N == 0) ? 0 : 1); 
    size_t num_iter = num_elem/(num_total_wi) + (((num_elem % (num_total_wi)) == 0) ?  0 : 1); 
    for(i = 0; i < num_iter; i++) { 
      size_t global_work_size[3] = {num_total_wi, 1, 1};  
      size_t local_ws[3] = {N, 1, 1}; 
      size_t global_offset[3] = {i * num_total_wi, 0, 0}; 

      clEnqueueNDRangeKernel(queue, kernel, 1, global_offset, global_work_size, local_ws, 0, NULL, NULL); 

    } 

回答

0

存储器传输是通过调用开始clEnqueueWriteBufferclEnqueueWriteImage但当clEnqueueNDRangeKernel被称为最有可能启动。一旦数据传输完毕,您可以随意重复使用内存对象,如果您没有再次明确说明,它将不会再次传输。