sudo apt-get update
sudo apt install opencl-headers
sudo apt install ocl-icd-libopencl1
sudo apt install ocl-icd-opencl-dev
sudo apt install clinfo
sudo apt-get update && sudo apt-get install cmake git g++
git clone https://github.com/krrishnarraj/clpeak
mkdir clpeak/build
cd clpeak/build
cmake ..
make -j$(nproc)
./clpeak
coolpi@Ubuntu:~/share/clpeak/build$ ./clpeak
arm_release_ver: g13p0-01eac0, rk_so_ver: 3
Platform: ARM Platform
Device: Mali-G610 r0p0
Driver version : 3.0 (Linux ARM64)
Compute units : 4
Clock frequency : 1000 MHz
Global memory bandwidth (GBPS)
float : 22.23
float2 : 23.83
float4 : 24.41
float8 : 19.66
float16 : 11.79
Single-precision compute (GFLOPS)
float : 447.13
float2 : 476.05
float4 : 471.84
float8 : 440.87
float16 : 415.77
Half-precision compute (GFLOPS)
half : 447.20
half2 : 888.10
half4 : 922.15
half8 : 897.12
half16 : 857.05
No double precision support! Skipped
Integer compute (GIOPS)
int : 126.60
int2 : 127.16
int4 : 126.57
int8 : 125.25
int16 : 125.70
Integer compute Fast 24bit (GIOPS)
int : 126.62
int2 : 127.18
int4 : 126.67
int8 : 125.28
int16 : 125.77
Transfer bandwidth (GBPS)
enqueueWriteBuffer : 7.76
enqueueReadBuffer : 8.84
enqueueWriteBuffer non-blocking : 7.79
enqueueReadBuffer non-blocking : 8.87
enqueueMapBuffer(for read) : 63.02
memcpy from mapped ptr : 10.38
enqueueUnmap(after write) : 63.96
memcpy to mapped ptr : 10.39
Kernel launch latency : 19.68 us
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef MAC
#include <OpenCL/cl.h>
#else
#include <CL/cl.h>
#endif
int main() {
/* Host data structures */
cl_platform_id *platforms;
//每一个cl_platform_id 结构表示一个在主机上的OpenCL执行平台，就是指电脑中支持OpenCL的硬件，如nvidia显卡，intel CPU和显卡，AMD显卡和CPU等
cl_uint num_platforms;
cl_int i, err, platform_index = -1;
/* Extension data */
char* ext_data;
size_t ext_size;
const char icd_ext[] = "cl_khr_icd";
//要使platform工作，需要两个步骤。1 需要为cl_platform_id结构分配内存空间。2 需要调用clGetPlatformIDs初始化这些数据结构。一般还需要步骤0：询问主机上有多少platforms
/* Find number of platforms */
//返回值如果为-1就说明调用函数失败，如果为0标明成功
//第二个参数为NULL代表要咨询主机上有多少个platform，并使用num_platforms取得实际flatform数量。
//第一个参数为1，代表我们需要取最多1个platform。可以改为任意大如：INT_MAX整数最大值。但是据说0，否则会报错，实际测试好像不会报错。下面是步骤0：询问主机有多少platforms
err = clGetPlatformIDs(5, NULL, &num_platforms);
if(err < 0) {
perror("Couldn't find any platforms.");
exit(1);
}
printf("I have platforms: %d\n", num_platforms); //本人计算机上显示为2，有intel和nvidia两个平台
/* Access all installed platforms */
//步骤1 创建cl_platform_id，并分配空间
platforms = (cl_platform_id*)
malloc(sizeof(cl_platform_id) * num_platforms);
//步骤2 第二个参数用指针platforms存储platform
clGetPlatformIDs(num_platforms, platforms, NULL);
/* Find extensions of all platforms */
//获取额外的平台信息。上面已经取得了平台id了，那么就可以进一步获取更加详细的信息了。
//一个for循环获取所有的主机上的platforms信息
for(i=0; i<num_platforms; i++)
{
/* Find size of extension data */
//也是和前面一样，先设置第三和第四个参数为0和NULL，然后就可以用第五个参数ext_size获取额外信息的长度了。
err = clGetPlatformInfo(platforms[i],
CL_PLATFORM_EXTENSIONS, 0, NULL, &ext_size);
if(err < 0)
{
perror("Couldn't read extension data.");
exit(1);
}
printf("The size of extension data is: %d\n", (int)ext_size);//我的计算机显示224.
/* Access extension data */
//这里的ext_data相当于一个缓存，存储相关信息。
ext_data = (char*)malloc(ext_size);
//这个函数就是获取相关信息的函数，第二个参数指明了需要什么样的信息，如这里的CL_PLATFORM_EXTENSIONS表示是opencl支持的扩展功能信息。我计算机输出一大串，机器比较新（专门为了学图形学而购置的电脑），支持的东西比较多。
clGetPlatformInfo(platforms[i], CL_PLATFORM_EXTENSIONS,
ext_size, ext_data, NULL);
printf("Platform %d supports extensions: %s\n", i, ext_data);
//这里是输出生产商的名字，比如我显卡信息是：NVIDIA CUDA
char *name = (char*)malloc(ext_size);
clGetPlatformInfo(platforms[i], CL_PLATFORM_NAME,
ext_size, name, NULL);
printf("Platform %d name: %s\n", i, name);
//这里是供应商信息，我显卡信息：NVIDIA Corporation
char *vendor = (char*)malloc(ext_size);
clGetPlatformInfo(platforms[i], CL_PLATFORM_VENDOR,
ext_size, vendor, NULL);
printf("Platform %d vendor: %s\n", i, vendor);
//最高支持的OpenCL版本，本机显示：OpenCL1.1 CUDA 4.2.1
char *version = (char*)malloc(ext_size);
clGetPlatformInfo(platforms[i], CL_PLATFORM_VERSION,
ext_size, version, NULL);
printf("Platform %d version: %s\n", i, version);
//这个只有两个值：full profile 和 embeded profile
char *profile = (char*)malloc(ext_size);
clGetPlatformInfo(platforms[i], CL_PLATFORM_PROFILE,
ext_size, profile, NULL);
printf("Platform %d full profile or embeded profile?: %s\n", i, profile);
/* Look for ICD extension */
//如果支持ICD这一扩展功能的platform，输出显示，本机的Intel和Nvidia都支持这一扩展功能
if(strstr(ext_data, icd_ext) != NULL)
platform_index = i;
//std::cout<<"Platform_index = "<<platform_index<<std::endl;
printf("Platform_index is: %d\n", platform_index);
/* Display whether ICD extension is supported */
if(platform_index > -1)
printf("Platform %d supports the %s extension.\n",
platform_index, icd_ext);
//释放空间
free(ext_data);
free(name);
free(vendor);
free(version);
free(profile);
}
if(platform_index <= -1)
printf("No platforms support the %s extension.\n", icd_ext);
/* Deallocate resources */
free(platforms);
return 0;
}
gcc opencl_hello.c -o opencl_hello -lOpenCL
coolpi@Ubuntu:~/share$ ./opencl_hello
I have platforms: 1
arm_release_ver: g13p0-01eac0, rk_so_ver: 3
The size of extension data is: 1364
Platform 0 supports extensions: cl_khr_global_int32_base_atomics cl_khr_global_int32_extended_atomics cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_byte_addressable_store cl_khr_3d_image_writes cl_khr_int64_base_atomics cl_khr_int64_extended_atomics cl_khr_fp16 cl_khr_icd cl_khr_egl_image cl_khr_image2d_from_buffer cl_khr_depth_images cl_khr_subgroups cl_khr_subgroup_extended_types cl_khr_subgroup_non_uniform_vote cl_khr_subgroup_ballot cl_khr_subgroup_non_uniform_arithmetic cl_khr_subgroup_shuffle cl_khr_subgroup_shuffle_relative cl_khr_subgroup_clustered_reduce cl_khr_subgroup_rotate cl_khr_il_program cl_khr_priority_hints cl_khr_create_command_queue cl_khr_spirv_no_integer_wrap_decoration cl_khr_extended_versioning cl_khr_device_uuid cl_khr_suggested_local_work_size cl_khr_extended_bit_ops cl_khr_integer_dot_product cl_khr_semaphore cl_khr_external_semaphore cl_khr_external_semaphore_sync_fd cl_khr_command_buffer cl_arm_core_id cl_arm_printf cl_arm_non_uniform_work_group_size cl_arm_import_memory cl_arm_import_memory_dma_buf cl_arm_import_memory_host cl_arm_integer_dot_product_int8 cl_arm_integer_dot_product_accumulate_int8 cl_arm_integer_dot_product_accumulate_saturate_int8 cl_arm_scheduling_controls cl_arm_controlled_kernel_termination cl_ext_cxx_for_opencl cl_ext_image_tiling_control cl_ext_image_requirements_info cl_ext_image_from_buffer
Platform 0 name: ARM Platform
Platform 0 vendor: ARM
Platform 0 version: OpenCL 3.0 v1.g13p0-01eac0.a8b6f0c7e1f83c654c60d1775112dbe4
Platform 0 full profile or embeded profile?: FULL_PROFILE
Platform_index is: 0
Platform 0 supports the cl_khr_icd extension.