mxnet build with intel mkl always throw error "Intel MKL FATAL ERROR: Cannot load mkl_intel_thread.dll."

Question

• os : windows 10 64bits
• compiler : vc2015 64bits update 3
• mxnet : 1.3.1

Building mxnet 1.3.1（mxnet1.4.0 has bugs, can't build it under windows，please check14203 for more details).

I can build the mxnet with cpp-package, but when I call the forward function o the Executor, it keep throwing

Intel MKL FATAL ERROR: Cannot load mkl_intel_thread.dll.

Following are my steps to build the mxnet

1. git clone --recursive https://github.com/apache/incubator-mxnet mxnet
2. cd mxnet
3. Download intel mkl(w_mkl_2019.2.190.exe)
4. install it
5. open cmake3.11.0
6. 

7. 

   • I disable cpp_package,opencv,cuda,USE_MKLML_MKL(else mshadow will use openBLAS).
   • I disable USE_TENSORRT and USE_VTUNE too

8. press configure，disable BUILD_TESTING

9. press configure again, all green
10. press generate，all green
11. open ALL_BUILD.vcxproj
12. Select Release build
13. All build
14. All green, except install project fail

>file cannot create directory: C:/Program Files/mxnet/lib. Maybe need 1> administrative privileges.

Already open vc as admin, still the same error

15. Add Anaconda3 into PATH
16. Add libmxnet.dll and C:\Program Files (x86)\IntelSWTools\compilers_and_libraries_2019.2.190\windows\redist\intel64_win\mkl\mkl_rt.dll into a folder which could be found by the os
17. select build with cpp_package from cmake gui
18. configure->generate
19. reopen ALL_BUILD.vcxproj
20. Select ALL_BUILD->build
21. Because install do not work，I copy the files lib to build_cpu/install

22. Because lrs and wds of op.h do not declare type，I need to add mx_float for them
23. write a simple program, can compile
24. When I call forward of the Executor，the program throw Intel MKL FATAL ERROR: Cannot load mkl_intel_thread.dll.
25. Add C:\Program Files (x86)\IntelSWTools\compilers_and_libraries_2019.2.190\windows\redist\intel64_win\mkl的mkl_intel_thread.dll into the folder could be found by the os 26.Run again，still the same error Intel MKL FATAL ERROR: Cannot load mkl_intel_thread.dll.

My Anaconda3 install mxnet，it got mkl_intel_thread.dll and mkl_rt.dll too，I wonder there are confliction，problem is I did not add the bin path of Anaconda3 into the PATH.

I tried to copy different mkl_intel_thread.dll and mkl_rt.dll into the folder where the exe at, but every combination of them give me same error.

Those dll come from following path

• C:\Program Files (x86)\IntelSWTools\compilers_and_libraries_2019.2.190\windows\redist\intel64_win\mkl
• C:\Users\yyyy\Anaconda3\envs\gluon\Library\bin
• C:\Users\yyyy\Anaconda3\Library\bin
• C:\Users\yyyy\Anaconda3\pkgs\mkl-2019.1-144\Library\bin

Do anyone know how to solve this issue?Thanks

Answer 1

This problem should be caused by static MKL linkage, here's some advice may helpful to you.

1. Have you ever tried to set environmental variable for pre-load libs,

Here is Linux

export LD_PRELOAD=/opt/intel/mkl/lib/intel64/libmkl_def.so:/opt/intel/mkl/lib/intel64/libmkl_avx2.so:/opt/intel/mkl/lib/intel64/libmkl_core.so:/opt/intel/mkl/lib/intel64/libmkl_intel_lp64.so:/opt/intel/mkl/lib/intel64/libmkl_intel_thread.so:/opt/intel/lib/intel64_lin/libiomp5.so

In windows, setting env by mkl/bin/mklvars.bat intel64, then run your python in same environment

or in python to add the library manually sys.path.append(" your path to the library") or Pyinstaller numpy "Intel MKL FATAL ERROR: Cannot load mkl_intel_thread.dll"...

2. If above suggestions did not help, please try to modify the 'CMakeList.txt' file, change line 44 ~ 47 to single-dynamic linkage and re-cmake to install:

   if(MSVC)
       set(LIBS ${LIBS} mkl_rt ${MKL_COMPILER_LIB_FILE} PARENT_SCOPE)
     else()
       set(LIBS ${LIBS} mkl_rt ${MKL_COMPILER_LIB_FILE} PARENT_SCOPE)