无法在基于 C 的 OpenCL 中创建子缓冲区

Question

我无法在 OpenCL vai 我的 c 代码中创建子缓冲区，它返回一个错误代码，表示无效值，我无法追踪它为什么不工作。

    #include <stdio.h>
#include <CL\cl.h>
#define LOG(...) printf(__VA_ARGS__);printf("\n");

static void logError(char * type, cl_int err);
void print_buffer_info();

int main() {
    print_buffer_info();
}

void print_buffer_info() {
    //Get Platform
    cl_platform_id *plid;
    cl_uint no_of_platforms;
    clGetPlatformIDs(2, NULL, &no_of_platforms);
    plid = malloc(sizeof(cl_platform_id)*no_of_platforms);
    clGetPlatformIDs(no_of_platforms, plid, NULL);
    LOG("No of platforms: %d", no_of_platforms);

    //get device 
    cl_device_id *dids;
    cl_uint dev_count;
    clGetDeviceIDs(plid[0], CL_DEVICE_TYPE_GPU, 2, NULL, &dev_count);
    LOG("No of device: %d", dev_count);
    dids = malloc(sizeof(cl_device_id)*dev_count);
    clGetDeviceIDs(plid[0], CL_DEVICE_TYPE_GPU, dev_count, dids, NULL);

    //get context
    cl_context ctxt= clCreateContext(NULL, 1, dids, NULL, NULL, NULL);

    float host_ptr[50];
    cl_int err;
    //create main buffer
    cl_mem main_buffer= clCreateBuffer(ctxt,
        CL_MEM_READ_ONLY | CL_MEM_COPY_HOST_PTR,
        sizeof(host_ptr),
        host_ptr, 
        &err);
    size_t size_main;
    clGetMemObjectInfo(main_buffer, CL_MEM_SIZE, 10, &size_main, &err);
    LOG("Size of main buffer: %d", size_main);
    logError("Main Buffer", err);

    //create sub-buffer
    cl_buffer_region region = {
        .origin = 10 * sizeof(float),
        .size = 10 * sizeof(float)
    };
    LOG("Origin: %d, Size: %d", region.origin, region.size);
    cl_mem sub_buffer = clCreateSubBuffer(main_buffer, 
        CL_MEM_READ_ONLY | CL_MEM_COPY_HOST_PTR, 
        CL_BUFFER_CREATE_TYPE_REGION, 
        &region,
        &err);
    logError("Sub-buffer", err);
    size_t size_sub;
    clGetMemObjectInfo(sub_buffer, CL_MEM_SIZE, 10, &size_sub, NULL);
    LOG("Size of sub buffer: %d", size_sub);
}

static void logError(char * type, cl_int err) {
    if (err < 0) {
        LOG("Cannot create %s : %d", type, err);
        if (CL_INVALID_MEM_OBJECT == err) {
            LOG("CL_INVALID_MEM_OBJECT");
        }
        if (CL_INVALID_VALUE == err) {
            LOG("CL_INVALID_VALUE ");
        }
        if (CL_OUT_OF_RESOURCES == err) {
            LOG("CL_OUT_OF_RESOURCES  ");
        }

        if (CL_OUT_OF_HOST_MEMORY == err) {
            LOG("CL_OUT_OF_HOST_MEMORY  ");
        }

        exit(1);
    }
}

这个程序给出结果：

平台数量：2 设备数量：1 主缓冲区大小：200 原产地：40，尺寸：40 无法创建子缓冲区：-30 CL_INVALID_VALUE

现在我无法弄清楚，为什么创建子缓冲区说：CL_INVALID_VALUE？

Answer 1

如果我这样声明我的子缓冲区，这个问题就解决了：

cl_mem sub_buffer = clCreateSubBuffer(main_buffer, 
        CL_MEM_READ_ONLY, //removed :CL_MEM_COPY_HOST_PTR
        CL_BUFFER_CREATE_TYPE_REGION, 
        &region,
        &err);