OpenCL-101
Learn OpenCL step by step as below.
- OpenCL Examples
- Installation Guide of OpenCL
1. OpenCL Examples
- vec-add-standard: An standard OpenCL example, accomplish addition operation of two int-type arrays (vectors).
- vec-add-simple: An simple addition operation of two vectors (NOT recommanded).
- bandwidth: Measure bandwith for various variable type.
- mat-transpose: An demo of matrix transpose with two OpenCL kernels.
2. Installation Guide of OpenCL
You can choose one or two ways to use OpenCL:
- Install OpenCL on Ubuntu 16.04 64-bit
- Using OpenCL by Docker
- Using OpenCL by WSL2
2.1 Install OpenCL on Ubuntu 16.04 64-bit
# below instructions refer linux安装opencl：ubuntu14.04+opencl1.1 - qccz123456的博客 - CSDN博客
# http://blog.csdn.net/qccz123456/article/details/52606788
$ sudo apt-get update
$ sudo apt-get install build-essential g++ cmake
$ sudo apt-get install clang libclang-3.4-dev libclang-dev libclang1
$ sudo apt-get install ocl-icd-opencl-dev ocl-icd-libopencl1
$ sudo apt-get install opencl-headers ocl-icd-dev ocl-icd-libopencl1
# below instructions refer Ubuntu 16.04.2 下为 Intel 显卡启用 OpenCL_Linux教程_Linux公社-Linux系统门户网站
# http://www.linuxidc.com/Linux/2017-03/141455.htm
$ sudo apt install ocl-icd-libopencl1
$ sudo apt install opencl-headers
$ sudo apt install clinfo
$ sudo apt install ocl-icd-opencl-dev
$ sudo apt install beignet2.2 Using OpenCL by Docker
Using Docker is convenient, which you don't need config and install enviroments for all about OpenCL. Of course, install Docker Community Edition first and then search relative images in DockerHub.
After finish Docker installation, please follow this instruction from chihchun/opencl-intel. If anything goes normally, using command below in command line:
$ docker run -t -i --device /dev/dri:/dev/dri \
chihchun/hashcat-beignet hashcat -bIt will print similar messages as Verify installation.
2.3 Verify Installation
Using instruction below, successful installation will print same following messages:
$ clinfo
# print message below
Number of platforms 1
Platform Name Intel Gen OCL Driver
Platform Vendor Intel
Platform Version OpenCL 1.2 beignet 1.1.1
Platform Profile FULL_PROFILE
Platform 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_spir cl_khr_icd
Platform Extensions function suffix Intel
Platform Name Intel Gen OCL Driver
Number of devices 1
Device Name Intel(R) HD Graphics IvyBridge M GT2
Device Vendor Intel
Device Vendor ID 0x8086
Device Version OpenCL 1.2 beignet 1.1.1
Driver Version 1.1.1
Device OpenCL C Version OpenCL C 1.2 beignet 1.1.1
Device Type GPU
Device Profile FULL_PROFILE
Max compute units 16
Max clock frequency 1000MHz
Device Partition (core)
Max number of sub-devices 1
Supported partition types None, None, None
Max work item dimensions 3
Max work item sizes 512x512x512
Max work group size 512
Preferred work group size multiple 16
Preferred / native vector sizes
char 16 / 8
short 8 / 8
int 4 / 4
long 2 / 2
half 0 / 8 (n/a)
float 4 / 4
double 0 / 2 (n/a)
Half-precision Floating-point support (n/a)
Single-precision Floating-point support (core)
Denormals No
Infinity and NANs Yes
Round to nearest Yes
Round to zero No
Round to infinity No
IEEE754-2008 fused multiply-add No
Support is emulated in software No
Correctly-rounded divide and sqrt operations No
Double-precision Floating-point support (n/a)
Address bits 32, Little-Endian
Global memory size 2147483648 (2GiB)
Error Correction support No
Max memory allocation 1073741824 (1024MiB)
Unified memory for Host and Device Yes
Minimum alignment for any data type 128 bytes
Alignment of base address 1024 bits (128 bytes)
Global Memory cache type Read/Write
Global Memory cache size 8192
Global Memory cache line 64 bytes
Image support Yes
Max number of samplers per kernel 16
Max size for 1D images from buffer 65536 pixels
Max 1D or 2D image array size 2048 images
Max 2D image size 8192x8192 pixels
Max 3D image size 8192x8192x2048 pixels
Max number of read image args 128
Max number of write image args 8
Local memory type Global
Local memory size 65536 (64KiB)
Max constant buffer size 134217728 (128MiB)
Max number of constant args 8
Max size of kernel argument 1024
Queue properties
Out-of-order execution No
Profiling Yes
Prefer user sync for interop Yes
Profiling timer resolution 80ns
Execution capabilities
Run OpenCL kernels Yes
Run native kernels Yes
SPIR versions <printDeviceInfo:138: get SPIR versions size : error -30>
printf() buffer size 1048576 (1024KiB)
Built-in kernels __cl_copy_region_align4;__cl_copy_region_align16;__cl_cpy_region_unalign_same_offset;__cl_copy_region_unalign_dst_offset;__cl_copy_region_unalign_src_offset;__cl_copy_buffer_rect;__cl_copy_image_1d_to_1d;__cl_copy_image_2d_to_2d;__cl_copy_image_3d_to_2d;__cl_copy_image
_2d_to_3d;__cl_copy_image_3d_to_3d;__cl_copy_image_2d_to_buffer;__cl_copy_image_3d_to_buffer;__cl_copy_buffer_to_image_2d;__cl_copy_buffer_to_image_3d;__cl_fill_region_unalign;__cl_fill_region_align2;__cl_fill_region_align4;__cl_fill_region_align8_2;__cl_fill_region_align8_4;__cl_fill_region_align8_8;__cl_fill_region_
align8_16;__cl_fill_region_align128;__cl_fill_image_1d;__cl_fill_image_1d_array;__cl_fill_image_2d;__cl_fill_image_2d_array;__cl_fill_image_3d;
Device Available Yes
Compiler Available Yes
Linker Available Yes
Device 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_spir cl_khr_icd
NULL platform behavior
clGetPlatformInfo(NULL, CL_PLATFORM_NAME, ...) Intel Gen OCL Driver
clGetDeviceIDs(NULL, CL_DEVICE_TYPE_ALL, ...) Success [Intel]
clCreateContext(NULL, ...) [default] Success [Intel]
clCreateContextFromType(NULL, CL_DEVICE_TYPE_CPU) No devices found in platform
clCreateContextFromType(NULL, CL_DEVICE_TYPE_GPU) Success (1)
Platform Name Intel Gen OCL Driver
Device Name Intel(R) HD Graphics IvyBridge M GT2
clCreateContextFromType(NULL, CL_DEVICE_TYPE_ACCELERATOR) No devices found in platform
clCreateContextFromType(NULL, CL_DEVICE_TYPE_CUSTOM) No devices found in platform
clCreateContextFromType(NULL, CL_DEVICE_TYPE_ALL) Success (1)
Platform Name Intel Gen OCL Driver
Device Name Intel(R) HD Graphics IvyBridge M GT2
ICD loader properties
ICD loader Name OpenCL ICD Loader
ICD loader Vendor OCL Icd free software
ICD loader Version 2.2.8
ICD loader Profile OpenCL 1.2
NOTE: your OpenCL library declares to support OpenCL 1.2,
but it seems to support up to OpenCL 2.1 too.
How to compile OpenCL example in GCC?
Precisely, the kernel compilation in OpenCL is make in running time (library call).
In Gcc, for compilation, you only need the headers (aviables on Kronos site). But for linkage, you have to install OpenCL compatible driver.
in the Makefile :
- for Mac OSX : -framework OpenCL
- for Linux : -lOpenCL
ref: How to compile OpenCL example in GCC?
https://forums.khronos.org/showthread.php/5728-How-to-compile-OpenCL-example-in-GCC
3. Using OpenCL by WSL2
- guide: https://devblogs.microsoft.com/commandline/oneapi-l0-openvino-and-opencl-coming-to-the-windows-subsystem-for-linux-for-intel-gpus/
- link: https://www.intel.com/content/www/us/en/artificial-intelligence/harness-the-power-of-intel-igpu-on-your-machine.html
Other problems
git error: unable to auto-detect email address
yuanshuai@firefly:~/code/OpenCL-101$ git commit -m "update README.md"
*** Please tell me who you are.
Run
git config --global user.email "[email protected]"
git config --global user.name "Your Name"
to set your account's default identity.
Omit --global to set the identity only in this repository.
fatal: unable to auto-detect email address (got 'yuanshuai@firefly.(none)')After following instructions above, it still occured same error message. I reset user.email and user.name using git config --local user.email "[email protected]" and git config --local user.name "Your name" and it's okay!
ref: git中报unable to auto-detect email address 错误的解决拌办法 - liufangbaishi2014的博客 - CSDN博客 http://blog.csdn.net/liufangbaishi2014/article/details/50037507