ubuntu - 如何在 Ubuntu 上为 AMD Ryzen Mobile CPU 安装 opencl

Question

我有一台配备 AMD Ryzen 5 2500u(集成了 radeon vega 8 移动 GPU)处理器的笔记本电脑，并使用 Ubuntu 18.04.2。我想在 CPU 和 GPU 上使用 C++ 运行一些 OpenCL 计算。我的问题是我不确定 opencl 如何识别 cpu。

我已经从 amd 网站和 AMD APP SDK 3.0 安装了 amdgpu-pro。运行 clinfo 后，我得到以下输出:

Number of platforms 2

Platform Name Clover

Platform Vendor Mesa

Platform Version OpenCL 1.1 Mesa 18.2.8

Platform Profile FULL_PROFILE

Platform Extensions cl_khr_icd

Platform Extensions function suffix MESA

Platform Name AMD Accelerated

Parallel Processing Platform Vendor Advanced Micro Devices, Inc.

Platform Version OpenCL 2.1 AMD-APP (2671.3)

Platform Profile FULL_PROFILE

Platform Extensions cl_khr_icd cl_amd_event_callback cl_amd_offline_devices

Platform Host timer resolution 1ns

Platform Extensions function suffix AMD

Platform Name Clover

Number of devices 1

Device Name AMD RAVEN (DRM 3.26.0, 4.18.0-16-generic, LLVM 7.0.0)

Device Vendor AMD

Device Vendor ID 0x1002

Device Version OpenCL 1.1 Mesa 18.2.8

Driver Version 18.2.8

Device OpenCL C Version OpenCL C 1.1

Device Type GPU

Device Profile FULL_PROFILE

Device Available Yes

Compiler Available Yes

Max compute units 8

Max clock frequency 1100MHz

Max work item dimensions 3

Max work item sizes 256x256x256

Max work group size 256

Preferred work group size multiple 64

Preferred / native vector sizes
char 16 / 16
short 8 / 8
int 4 / 4
long 2 / 2
half 8 / 8 (cl_khr_fp16) float 4 / 4
double 2 / 2 (cl_khr_fp64)

Half-precision Floating-point support (cl_khr_fp16)

...

Platform Name AMD Accelerated Parallel Processing

Number of devices 1

Device Name gfx902

Device Vendor Advanced Micro Devices, Inc.

Device Vendor ID 0x1002

Device Version OpenCL 1.2 AMD-APP (2671.3)

Driver Version 2671.3 (PAL,HSAIL)

Device OpenCL C Version OpenCL C 1.2

Device Type GPU

Device Board Name (AMD) Unknown AMD GPU

Device Topology (AMD) PCI-E, 05:00.0

Device Profile FULL_PROFILE

.......

NULL platform behavior

clGetPlatformInfo(NULL, CL_PLATFORM_NAME, ...) No platform

clGetDeviceIDs(NULL, CL_DEVICE_TYPE_ALL, ...) No platform

clCreateContext(NULL, ...) [default] No platform

clCreateContext(NULL, ...) [other] Success [MESA]

clCreateContextFromType(NULL, CL_DEVICE_TYPE_DEFAULT) Success (1)

Platform Name                                 Clover

Device Name                                   AMD RAVEN (DRM 3.26.0, 4.18.0-16-generic, LLVM 7.0.0)

clCreateContextFromType(NULL, CL_DEVICE_TYPE_CPU) No devices found in platform

clCreateContextFromType(NULL, CL_DEVICE_TYPE_GPU) Success (1)

Platform Name                                 Clover

Device Name                                   AMD RAVEN (DRM 3.26.0, 4.18.0-16-generic, LLVM 7.0.0)

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                                 Clover

Device Name                                   AMD RAVEN (DRM 3.26.0, 4.18.0-16-generic, LLVM 7.0.0)

带有设备“AMD RAVEN (DRM 3.26.0, 4.18.0-16-generic, LLVM 7.0.0)”的第一个平台“Clover”具有设备类型“GPU”，第二个平台带有设备“gfx902”似乎也是我系统的 GPU。

所以我的问题是:我必须安装什么才能让 opencl 也识别我系统的 cpu？

感谢您的帮助!

Answer 1

将 CPU 与 OpenCL 结合使用自然需要支持 CPU 的 OpenCL 实现。特别是POCL应该可用。 AMD 似乎已经放弃了他们的 CPU OpenCL 实现，而英特尔声称他们的 OpenCL 仅适用于他们的处理器品牌。

顺便说一句，如果尝试将工作自动分配给所有设备，则为同一设备(例如 Clover 和 APP)混合 OpenCL 实现可能会产生令人惊讶的结果。如果您可以指定要使用的设备应该没问题。