[petsc-users] Problems with DMDAVecGetArrayF90 + Intel

[Randall Mackie]

Thanks Satish, we’ve submitted a bug report with Intel and are following up with them.

Randy


> On Apr 12, 2018, at 12:08 AM, Satish Balay <balay at mcs.anl.gov> wrote:
> 
> I see this error with "-xAVX" build aswell.
> 
> Satish
> 
> On Wed, 11 Apr 2018, Zhang, Hong wrote:
> 
>> Performance wise, I would suggest to use "-xAVX" instead of "-axcore-avx2". Based on our experience with running PETSc on a variety of Xeon processors (including KNL), using AVX2 yields comparable and sometimes worse performance than using AVX. But if your machine supports AVX-512, it is definitely beneficial to use AVX-512.
>> 
>> Hong (Mr.)
>> 
>>> On Apr 5, 2018, at 10:03 AM, Randall Mackie <rlmackie862 at gmail.com> wrote:
>>> 
>>> Dear PETSc users,
>>> 
>>> I’m curious if anyone else experiences problems using DMDAVecGetArrayF90 in conjunction with Intel compilers?
>>> We have had many problems (typically 11 SEGV segmentation violations) when PETSc is compiled in optimize mode (with various combinations of options).
>>> These same codes run valgrind clean with gfortran, so I assume this is an Intel bug, but before we submit a bug report I wanted to see if anyone else had similar experiences?
>>> We have basically gone back and replaced our calls to DMDAVecGetArrayF90 with calls to VecGetArrayF90 and pass those pointers into a “local” subroutine that works fine.
>>> 
>>> In case anyone is curious, the attached test code shows this behavior when PETSc is compiled with the following options:
>>> 
>>> ./configure \
>>> --with-clean=1 \
>>> --with-debugging=0 \
>>> --with-fortran=1 \
>>> --with-64-bit-indices \
>>> --download-mpich=../mpich-3.3a2.tar.gz \
>>> --with-blas-lapack-dir=/opt/intel/mkl \
>>> --with-cc=icc \
>>> --with-fc=ifort \
>>> --with-cxx=icc \
>>> --FOPTFLAGS='-O2 -xSSSE3 -axcore-avx2' \
>>> --COPTFLAGS='-O2 -xSSSE3 -axcore-avx2' \
>>> --CXXOPTFLAGS='-O2 -xSSSE3 -axcore-avx2’ \
>>> 
>>> 
>>> 
>>> Thanks, Randy M.
>>> 
>>> <cmd_test><makefile><test.F90>
>> 
>>