MacBook（AMD显卡）配置PyTorch MPS加速失败求助

问题 #

设备是搭载Radeon Pro 555显卡、运行Ventura系统的MacBook，想配置PyTorch的MPS加速来跑Stable Diffusion。按苹果官方教程操作后，用Python脚本验证MPS支持时出现了RuntimeError。已经把Python从3.12.1降级到3.11.1，还重装了最新的PyTorch nightly版本，但问题依旧没解决。

验证代码和错误信息如下：

Python 3.11.1 (v3.11.1:a7a450f84a, Dec  6 2022, 15:24:06) [Clang 13.0.0 (clang-1300.0.29.30)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import torch
>>> if torch.backends.mps.is_available():
...     mps_device = torch.device("mps")
...     x = torch.ones(1, device=mps_device)
...     print (x)
... else:
...     print ("MPS device not found.")
... 
Traceback (most recent call last):
  File "<stdin>", line 4, in <module>
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/torch/_tensor.py", line 461, in __repr__
    return torch._tensor_str._str(self, tensor_contents=tensor_contents)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/torch/_tensor_str.py", line 677, in _str
    return _str_intern(self, tensor_contents=tensor_contents)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/torch/_tensor_str.py", line 597, in _str_intern
    tensor_str = _tensor_str(self, indent)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/torch/_tensor_str.py", line 349, in _tensor_str
    formatter = _Formatter(get_summarized_data(self) if summarize else self)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/torch/_tensor_str.py", line 137, in __init__
    nonzero_finite_vals = torch.masked_select(
                          ^^^^^^^^^^^^^^^^^^^^
RuntimeError: Failed to create indexing library, error: Error Domain=MTLLibraryErrorDomain Code=3 "program_source:168:1: error: type 'const constant ulong3 *' is not valid for attribute 'buffer'
REGISTER_INDEX_OP_ALL_DTYPES(select);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
program_source:160:5: note: expanded from macro 'REGISTER_INDEX_OP_ALL_DTYPES'
    REGISTER_INDEX_OP(8bit,  idx64, char,  INDEX_OP_TYPE, ulong3);    \
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
program_source:138:5: note: expanded from macro 'REGISTER_INDEX_OP'
    constant IDX_DTYPE   * offsets           [[buffer(3)]],                        \
    ^                                          ~~~~~~~~~
program_source:168:1: note: type 'ulong3' (vector of 3 'unsigned long' values) cannot be used in buffer pointee type
program_source:160:59: note: expanded from macro 'REGISTER_INDEX_OP_ALL_DTYPES'
    REGISTER_INDEX_OP(8bit,  idx64, char,  INDEX_OP_TYPE, ulong3);    \
                                                          ^
program_source:168:1: error: explicit instantiation of 'index_select' does not refer to a function template, variable template, member function, member class, or static data member
REGISTER_INDEX_OP_ALL_DTYPES(select);
^
program_source:160:5: note: expanded from macro 'REGISTER_INDEX_OP_ALL_DTYPES'
    REGISTER_INDEX_OP(8bit,  idx64, char,  INDEX_OP_TYPE, ulong3);    \
    ^
program_source:134:13: note: expanded from macro 'REGISTER_INDEX_OP'
kernel void index_ ## INDEX_OP_TYPE<DTYPE, IDX_DTYPE>(                             \
            ^
<scratch space>:9:1: note: expanded from here
index_select
^
program_source:20:13: note: candidate template ignored: substitution failure [with T = char, OffsetsT = unsigned long __attribute__((ext_vector_type(3)))]: type 'unsigned long const constant * __attribute__((ext_vector_type(3)))' is not valid for attribute 'buffer'
kernel void index_select(
            ^
program_source:168:1: error: type 'const constant ulong3 *' is not valid for attribute 'buffer'
REGISTER_INDEX_OP_ALL_DTYPES(select);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
program_source:162:5: note: expanded from macro 'REGISTER_INDEX_OP_ALL_DTYPES'
    REGISTER_INDEX_OP(16bit, idx64, short, INDEX_OP_TYPE, ulong3);    \
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
program_source:138:5: note: expanded from macro 'REGISTER_INDEX_OP'
    constant IDX_DTYPE   * offsets           [[buffer(3)]],                        \
    ^                                          ~~~~~~~~~
program_source:168:1: note: type 'ulong3' (vector of 3 'unsigned long' values) cannot be used in buffer pointee type
program_source:162:59: note: expanded from macro 'REGISTER_INDEX_OP_ALL_DTYPES'
    REGISTER_INDEX_OP(16bit, idx64, short, INDEX_OP_TYPE, ulong3);    \
                                                          ^
program_source:168:1: error: explicit instantiation of 'index_select' does not refer to a function template, variable template, member function, member class, or static data member
REGISTER_INDEX_OP_ALL_DTYPES(select);
^
program_source:162:5: note: expanded from macro 'REGISTER_INDEX_OP_ALL_DTYPES'
    REGISTER_INDEX_OP(16bit, idx64, short, INDEX_OP_TYPE, ulong3);    \
    ^
program_source:134:13: note: expanded from macro 'REGISTER_INDEX_OP'
kernel void index_ ## INDEX_OP_TYPE<DTYPE, IDX_DTYPE>(                             \
            ^
<scratch space>:17:1: note: expanded from here
index_select
^

....
...
program_source:248:13: note: candidate template ignored: substitution failure [with T = metal::_atomic<int, void>, E = int, OffsetsT = unsigned long __attribute__((ext_vector_type(3)))]: type 'unsigned long const constant * __attribute__((ext_vector_type(3)))' is not valid for attribute 'buffer'
kernel void index_put_accumulate_native_dtypes(
            ^
}

解决方案 #

1. 降级PyTorch到兼容版本 #

你的Radeon Pro 555属于AMD GCN 4架构，PyTorch nightly版本使用了较新的Metal特性，老显卡不支持。换用PyTorch 2.0.1稳定版，这个版本的MPS实现兼容老款AMD显卡：

pip install torch==2.0.1 torchvision==0.15.2 torchaudio==2.0.2

2. 重新验证MPS支持 #

安装完成后，再次运行验证代码，确认MPS可以正常工作：

import torch
if torch.backends.mps.is_available():
    mps_device = torch.device("mps")
    x = torch.ones(1, device=mps_device)
    print(x)
else:
    print("MPS device not found.")

3. 配置Stable Diffusion使用MPS #

在Stable Diffusion的启动脚本里指定MPS设备：

import torch
device = torch.device("mps" if torch.backends.mps.is_available() else "cpu")

或者在启动命令里加参数--device mps（不同版本的Stable Diffusion参数可能略有不同，按需调整）。

4. 更新系统补丁 #

把Ventura系统更新到最新补丁版本（比如13.6及以上），Apple会在补丁里修复部分Metal兼容性问题。

内容的提问来源于stack exchange，提问作者Pica