topic Hi Gennady, in Intel® oneAPI Math Kernel Library

possible bug in 18.0.2 mkl

may_ka — Wed, 30 May 2018 21:45:09 GMT

Hi there,

the following code yield as segfault at run time:

Program Test
  use lapack95
  Implicit none
  Real*8, allocatable :: x(:,:)
  Integer*8 :: ISError
  if(allocated(x)) Then
    call DPOTRF_F95(A=x,UPLO="U",INFO=ISError)
  End if
End Program Test

compier flags were:

ifort -i8 -warn nounused -warn declarations -O0 -check all -warn interface -check noarg_temp_created -static -c -o NoOMP_MKLSEQ_ifort_4.16.12-1-ARCH/Test.o Test.f90 -I /opt/intel/compilers_and_libraries_2018.2.199/linux/mkl/include/intel64/ilp64

linker flags were:

ifort -i8 -warn nounused -warn declarations -O0 -check all -warn interface -check noarg_temp_created -static -o Test_NoOMP_MKLSEQ_4.16.12-1-ARCH NoOMP_MKLSEQ_ifort_4.16.12-1-ARCH/Test.o    /opt/intel/compilers_and_libraries_2018.2.199/linux/mkl/lib/intel64/libmkl_blas95_ilp64.a /opt/intel/compilers_and_libraries_2018.2.199/linux/mkl/lib/intel64/libmkl_lapack95_ilp64.a -Wl,--start-group /opt/intel/compilers_and_libraries_2018.2.199/linux/mkl/lib/intel64/libmkl_intel_ilp64.a /opt/intel/compilers_and_libraries_2018.2.199/linux/mkl/lib/intel64/libmkl_core.a /opt/intel/compilers_and_libraries_2018.2.199/linux/mkl/lib/intel64/libmkl_sequential.a -Wl,--end-group -lpthread -lm -ldl

runtime output were:

user@linux:~/./Test_NoOMP_MKLSEQ_4.16.12-1-ARCH
Segmentation fault (core dumped)

ifort parallel studio version: 18.0.2, linux kernel: 4.16.12

Does run in 17.07.

Is this a bug and if yes is that fixed in 18.0.3??

Thanks

Cheers

Karl

Update:

may_ka — Thu, 31 May 2018 03:07:54 GMT

Update:

Just installed 18.0.3

stlll the same problem.

Thanks for the report we will

Gennady_F_Intel — Thu, 31 May 2018 05:15:32 GMT

Thanks for the report we will check the problem. But looking at your example, I see potrf routine has not been called at all because of the array X is not allocated. What do check then? It seems you need to allocate and initialize the input X(:,:) array, isn't ?

Hi Gennady,

may_ka — Thu, 31 May 2018 07:42:52 GMT

Hi Gennady,

thanks for the response.

The fact that mkl lapack is not called at all makes it even more wired. The program crashes immediately when started. Only when the mkl lapack call is commented out it works. I have no idea whats going on. Thats why I reported thet compiler and linker flags as well.

Hope that helps.

Cheers

Hi Gennady,

may_ka — Fri, 01 Jun 2018 14:03:48 GMT

Hi Gennady,

the problem seems to be limited to the sequential version of mkl. When linking to the threaded version, its running.

cheers

I am wondering what has

may_ka — Wed, 13 Feb 2019 22:22:29 GMT

I am wondering what has happend to this. I initiated a support ticket which went asleep. I tested 19.02 today and the bug seems to be still not fixed!!

Hello Karl,

Kirill_V_Intel — Wed, 13 Feb 2019 22:32:14 GMT

Hello Karl,

AFAIK, this issue is related to linking with -static in combination with -lpthread (you find a lot information if you search for something like "static pthread segfault") and thus it is not a problem of the MKL. The known fix is to add to your link line the following:
-Wl,--whole-archive -lpthread -Wl,--no-whole-archive

Let me know if this doesn't work for you.

Best,
Kirill

Thanks

may_ka — Wed, 13 Feb 2019 22:44:35 GMT

Thanks