Python 如何限制NumPy'使用的线程数；Windows上有OpenBlas吗？

我正在分析Python中脚本的执行时间，我想关闭MKL/OpenBLAS优化。如何在Windows上正确执行此操作

我通过pip安装了带有Python 3.6和numpy 1.16.3的Windows 10 x64

我尝试在Windows（

OPENBLAS\u NUM\u THREADS

，

MKL\u NUM\u THREADS

，

NUMEXPR\u THREADS

，

VECLIB\u MAXIMUM\u THREADS

）和Python脚本中设置系统环境变量：

import os

os.environ["OMP_NUM_THREADS"] = "1"
os.environ["OPENBLAS_NUM_THREADS"] = "1"
os.environ["MKL_NUM_THREADS"] = "1"
os.environ["NUMEXPR_NUM_THREADS"] = "1"
os.environ["VECLIB_MAXIMUM_THREADS"] = "1"

但是执行这段代码：

import numpy as np
N = 10**4
a = np.random.random((N, N))
b = a@a

仍然使用多个线程

我的

np.\uuuu config\uuuuu.show（）

如下所示：

blas_mkl_info:
  NOT AVAILABLE
blis_info:
  NOT AVAILABLE
openblas_info:
    library_dirs = ['C:\\projects\\numpy-wheels\\numpy\\build\\openblas']
    libraries = ['openblas']
    language = f77
    define_macros = [('HAVE_CBLAS', None)]
blas_opt_info:
    library_dirs = ['C:\\projects\\numpy-wheels\\numpy\\build\\openblas']
    libraries = ['openblas']
    language = f77
    define_macros = [('HAVE_CBLAS', None)]
lapack_mkl_info:
  NOT AVAILABLE
openblas_lapack_info:
    library_dirs = ['C:\\projects\\numpy-wheels\\numpy\\build\\openblas']
    libraries = ['openblas']
    language = f77
    define_macros = [('HAVE_CBLAS', None)]
lapack_opt_info:
    library_dirs = ['C:\\projects\\numpy-wheels\\numpy\\build\\openblas']
    libraries = ['openblas']
    language = f77
    define_macros = [('HAVE_CBLAS', None)]

start /affinity 0x4 python script.py

在我的电脑上没有类似于

C:\\projects\\numpy wheels\\numpy\\build\\openblas

的路径，它必须是编译库的机器的路径

我在一个线程上实现执行的技巧是从CMD运行脚本，如下所示：

blas_mkl_info:
  NOT AVAILABLE
blis_info:
  NOT AVAILABLE
openblas_info:
    library_dirs = ['C:\\projects\\numpy-wheels\\numpy\\build\\openblas']
    libraries = ['openblas']
    language = f77
    define_macros = [('HAVE_CBLAS', None)]
blas_opt_info:
    library_dirs = ['C:\\projects\\numpy-wheels\\numpy\\build\\openblas']
    libraries = ['openblas']
    language = f77
    define_macros = [('HAVE_CBLAS', None)]
lapack_mkl_info:
  NOT AVAILABLE
openblas_lapack_info:
    library_dirs = ['C:\\projects\\numpy-wheels\\numpy\\build\\openblas']
    libraries = ['openblas']
    language = f77
    define_macros = [('HAVE_CBLAS', None)]
lapack_opt_info:
    library_dirs = ['C:\\projects\\numpy-wheels\\numpy\\build\\openblas']
    libraries = ['openblas']
    language = f77
    define_macros = [('HAVE_CBLAS', None)]

start /affinity 0x4 python script.py

---

但是这不是管理数学库优化的正确方法（我不确定这个命令是否真的限制了OpenBLAS）。

您应该设置env variable

OMP_NUM_THREADS=1

我尝试过-它不起作用。您应该设置env variable

OMP_NUM_THREADS=1

我尝试过-它不起作用。