在OpenCL中创建子缓冲区 [英] creating subbuffer in openCL
本文介绍了在OpenCL中创建子缓冲区的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我正在尝试在OpenCL中运行我的第一批代码。为了创建子缓冲区,我有"OpenCL in Action"一书中的以下代码。代码显示创建子缓冲区失败的错误。我的电脑配备英特尔CPU和NVIDIA GPU。然而,当我在另一台装有AMD CPU和GPU的计算机上运行代码时,它工作得很好。你知道为什么这个代码不能在非AMD平台上运行吗? 以下是错误:
代码是这样的:
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#ifdef MAC
#include <OpenCL/cl.h>
#else
#include <CL/cl.h>
#endif
/* Find a GPU or CPU associated with the first available platform */
cl_device_id create_device() {
cl_platform_id platform;
cl_device_id dev;
int err;
/* Identify a platform */
err = clGetPlatformIDs(1, &platform, NULL);
if (err < 0) {
perror("Couldn't identify a platform");
exit(1);
}
/* Access a device */
err = clGetDeviceIDs(platform, CL_DEVICE_TYPE_GPU, 1, &dev, NULL);
if (err == CL_DEVICE_NOT_FOUND) {
err = clGetDeviceIDs(platform, CL_DEVICE_TYPE_CPU, 1, &dev, NULL);
}
if (err < 0) {
perror("Couldn't access any devices");
exit(1);
}
return dev;
}
int main() {
/* Host/device data structures */
cl_device_id device;
cl_context context;
cl_int err;
/* Data and buffers */
float main_data[100] = {};
cl_mem main_buffer, sub_buffer;
void *main_buffer_mem = NULL, *sub_buffer_mem = NULL;
size_t main_buffer_size, sub_buffer_size;
cl_buffer_region region;
/* Create device and context */
device = create_device();
context = clCreateContext(NULL, 1, &device, NULL, NULL, &err);
if (err < 0) {
perror("Couldn't create a context");
exit(1);
}
/* Create a buffer to hold 100 floating-point values */
main_buffer = clCreateBuffer(context, CL_MEM_READ_ONLY |
CL_MEM_COPY_HOST_PTR, sizeof(main_data), main_data, &err);
if (err < 0) {
perror("Couldn't create a buffer");
exit(1);
}
/* Create a sub-buffer */
/* Modified on 2/12/2014 to account for unaligned memory error */
region.origin = 0 * sizeof(float);
region.size = 20 * sizeof(float);
sub_buffer = clCreateSubBuffer(main_buffer, CL_MEM_READ_ONLY |
CL_MEM_COPY_HOST_PTR, CL_BUFFER_CREATE_TYPE_REGION, ®ion, &err);
if (err < 0) {
perror("Couldn't create a sub-buffer.");
exit(1);
}
/* Obtain size information about the buffers */
clGetMemObjectInfo(main_buffer, CL_MEM_SIZE,
sizeof(main_buffer_size), &main_buffer_size, NULL);
clGetMemObjectInfo(sub_buffer, CL_MEM_SIZE,
sizeof(sub_buffer_size), &sub_buffer_size, NULL);
printf("Main buffer size: %lu
", main_buffer_size);
printf("Sub-buffer size: %lu
", sub_buffer_size);
/* Obtain the host pointers */
clGetMemObjectInfo(main_buffer, CL_MEM_HOST_PTR, sizeof(main_buffer_mem),
&main_buffer_mem, NULL);
clGetMemObjectInfo(sub_buffer, CL_MEM_HOST_PTR, sizeof(sub_buffer_mem),
&sub_buffer_mem, NULL);
printf("Main buffer memory address: %p
", main_buffer_mem);
printf("Sub-buffer memory address: %p
", sub_buffer_mem);
/* Print the address of the main data */
printf("Main array address: %p
", main_data);
/* Deallocate resources */
clReleaseMemObject(main_buffer);
clReleaseMemObject(sub_buffer);
clReleaseContext(context);
return 0;
}
推荐答案
因为您在创建main_buffer
时已经为缓冲区分配了内存,所以在获取子缓冲区时不需要再次分配内存。您应该仅使用CL_MEM_READ_ONLY
作为cl_mem_flags
:
sub_buffer = clCreateSubBuffer(main_buffer, CL_MEM_READ_ONLY,
CL_BUFFER_CREATE_TYPE_REGION, ®ion, &err);
这篇关于在OpenCL中创建子缓冲区的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
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