VML crash when calling custom DLL from multiple threads on Windows 7 x64

gabriel_i_r — Tue, 27 Sep 2011 19:36:12 GMT

Hello,

Im encountering crashes when calling MKL Vector Math Library (VML) functions in a custom DLL from a multithreaded C# program on 64-bit Windows 7.

The crash occurs when calling vsAdd, but not when calling cblas_saxpy, and only occurs when calling into a custom DLL (built using the makefile in the MKL builder directory). Calling mkl_rt.dll works ok. Using more than 1 thread is necessary to cause the crash, and it is not entirely deterministic.

I have put together a small, self-contained test-case to demonstrate the problem: In the attached ZIP archive, youll find two Windows batch files and a C# source file. Execute the batch files to build the custom DLL and 4 different programs, each for a slight variation of the test case (you may need to adjust the paths in the batch files and in the C# source file: I'm using MKL 10.3 update 6 installed in the default directory on Win 7 x64).

Run each of the four generated test-*.exe programs. On my system, 3 of the 4 execute and quit cleanly without errors. However test-custom-vml.exe will crash about 75% of the time. As you can see by inspecting the C# source and the batch files, the only difference among the 4 is in which MKL function is called (vsAdd vs cblas_saxpy) and whether the function resides in mkl_rt.dll or mkl_custom.dll

I've reproduced this problem on a Xeon E5335 system and on a Core i7 970 system, though the crash probability on the Core i7 system is somewhat lower than the Xeon (you'll have to try running it several times). 32-bit DLLs (built with nmake libia32) appear to have the same problem as well. Haven't tried other operating systems.

I'm not experienced with debugging non-managed code, but as best I can tell the problem occurs as the threads are shutting down. Debugging test-custom-vml.exe in Visual Studio 2010 brings up a message about heap corruption.

Any help on how I can get the VML to work from the custom DLL would be appreciated. I know the MKL is supposed to be thread-safe, and I'm even calling MKL_Set_Num_Threads(1) at the top of my program, so this crash is confusing.

Thank you in advance for your time.

Regards,

Gabriel

VML crash when calling custom DLL from multiple threads on Wind

Gennady_F_Intel — Wed, 28 Sep 2011 05:57:13 GMT

Gabriel, thanks for the issue - we will check how it works on our side and will back soon.

VML crash when calling custom DLL from multiple threads on Wind

Gennady_F_Intel — Wed, 28 Sep 2011 12:52:57 GMT

The problem has been reproduced on our side to.The root cause investigation of the problem is ongoing.

topic VML crash when calling custom DLL from multiple threads on Windows 7 x64 in Intel® oneAPI Math Kernel Library

VML crash when calling custom DLL from multiple threads on Windows 7 x64

VML crash when calling custom DLL from multiple threads on Wind

VML crash when calling custom DLL from multiple threads on Wind