Re: [OMPI users] OpenMPI 4.1.0 misidentifies x86 capabilities

[Jeff Squyres (jsquyres) via users]

On Feb 11, 2021, at 11:55 AM, Max R. Dechantsreiter  
wrote:
> 
> Not sure about the latest, but I built v4.1.x-202102090356-380ac96
> without errors, then used that to successfully build andd test
> GROMACS parallel mdrun.

Great!

> While I do not like using non-release versions, this is promising;
> will there be a bugfix release any time soon?

We just released 4.1.1RC1 yesterday: 
https://www.mail-archive.com/devel@lists.open-mpi.org/msg21252.html

-- 
Jeff Squyres
jsquy...@cisco.com

Re: [OMPI users] OpenMPI 4.1.0 misidentifies x86 capabilities

[Max R. Dechantsreiter via users]

On Thu, Feb 11, 2021 at 04:46:44PM +, Jeff Squyres (jsquyres) wrote:
> We did have some issues with 4.1.0 and AVX, but we have fixed everything that 
> we were aware of.
> 
> I'd be curious to know if you still have build failures in the latest 4.1.x 
> nightly snapshot.

Not sure about the latest, but I built v4.1.x-202102090356-380ac96
without errors, then used that to successfully build andd test
GROMACS parallel mdrun.

While I do not like using non-release versions, this is promising;
will there be a bugfix release any time soon?

> If you do, can you send the following:
> 
> - stdout/stderr from running configure
> - config.log
> - stdout/stderr from running "make V=1" (for brevity, you can "make", get to 
> the failure, and then "make V=1" to get just the details of the compile 
> failure, vs. the details of the entire make with oodles of lengthy successful 
> compiles)

(I find it is better to set MAKEFLAGS="VERBOSE=1" to be sure any
submakes get the news - I always build that way.)

> 
> 
> > On Feb 11, 2021, at 9:15 AM, Max R. Dechantsreiter 
> >  wrote:
> > 
> > ...The error that prompted me to start this thread occurred
> > during "make all" with 4.1.0:
> > 
> > .
> > .
> > .
> > Making all in mca/op/avx
> > gmake[2]: Entering directory 
> > `/home/maxd/XX/Build/openmpi-4.1.0_gcc-10.2.0/ompi/mca/op/avx'
> >  CC   op_avx_component.lo
> >  CC   liblocal_ops_avx_la-op_avx_functions.lo
> >  CCLD liblocal_ops_avx.la
> >  CC   liblocal_ops_avx512_la-op_avx_functions.lo
> > op_avx_functions.c: In function 'ompi_op_avx_2buff_bxor_uint64_t_avx512':
> > op_avx_functions.c:208:21: warning: AVX512F vector return without AVX512F 
> > enabled changes the ABI [-Wpsabi]
> >  208 | __m512i vecA =  _mm512_loadu_si512((__m512i*)in);
> >\
> >  | ^~~~
> > op_avx_functions.c:263:5: note: in expansion of macro 
> > 'OP_AVX_AVX512_BIT_FUNC'
> >  263 | OP_AVX_AVX512_BIT_FUNC(name, type_size, type, op);   
> >\
> >  | ^~
> > op_avx_functions.c:573:5: note: in expansion of macro 'OP_AVX_BIT_FUNC'
> >  573 | OP_AVX_BIT_FUNC(bxor, 64, uint64_t, xor)
> >  | ^~~
> > In file included from 
> > /home/maxd/XX/opt/gnu/gcc-10.2.0/lib/gcc/x86_64-linux-gnu/10.2.0/include/immintrin.h:55,
> > from op_avx_functions.c:26:
> > op_avx_functions.c: In function 'ompi_op_avx_2buff_max_int8_t_avx512':
> > /home/maxd/XX/opt/gnu/gcc-10.2.0/lib/gcc/x86_64-linux-gnu/10.2.0/include/avx512fintrin.h:6429:1:
> >  error: inlining failed in call to 'always_inline' '_mm512_storeu_si512': 
> > target specific option mismatch
> > 6429 | _mm512_storeu_si512 (void *__P, __m512i __A)
> >  | ^~~
> > op_avx_functions.c:73:13: note: called from here
> >   73 | _mm512_storeu_si512((__m512*)out, res);  
> >   \
> >  | ^~
> > op_avx_functions.c:124:5: note: in expansion of macro 'OP_AVX_AVX512_FUNC'
> >  124 | OP_AVX_AVX512_FUNC(name, type_sign, type_size, type, op);
> >   \
> >  | ^~
> > op_avx_functions.c:454:5: note: in expansion of macro 'OP_AVX_FUNC'
> >  454 | OP_AVX_FUNC(max, i, 8,int8_t, max)
> >  | ^~~
> > In file included from 
> > /home/maxd/XX/opt/gnu/gcc-10.2.0/lib/gcc/x86_64-linux-gnu/10.2.0/include/immintrin.h:65,
> > from op_avx_functions.c:26:
> > /home/maxd/XX/opt/gnu/gcc-10.2.0/lib/gcc/x86_64-linux-gnu/10.2.0/include/avx512bwintrin.h:1984:1:
> >  error: inlining failed in call to 'always_inline' '_mm512_max_epi8': 
> > target specific option mismatch
> > 1984 | _mm512_max_epi8 (__m512i __A, __m512i __B)
> >  | ^~~
> > op_avx_functions.c:72:27: note: called from here
> >   72 | __m512i res = 
> > _mm512_##op##_ep##type_sign##type_size(vecA, vecB);  \
> >  |   
> > ^~
> > op_avx_functions.c:124:5: note: in expansion of macro 'OP_AVX_AVX512_FUNC'
> >  124 | OP_AVX_AVX512_FUNC(name, type_sign, type_size, type, op);
> >   \
> >  | ^~
> > op_avx_functions.c:454:5: note: in expansion of macro 'OP_AVX_FUNC'
> >  454 | OP_AVX_FUNC(max, i, 8,int8_t, max)
> >  | ^~~
> > In file included from 
> > /home/maxd/XX/opt/gnu/gcc-10.2.0/lib/gcc/x86_64-linux-gnu/10.2.0/include/immintrin.h:55,
> > from op_avx_functions.c:26:
> > .
> > .
> > .
> > 
> > End result: the build failed.
> > 
> > My build of v4.1.x-202102090356-380ac96 threw no errors.
> > I will continue with an attempt to build GROMACS using
> > that 4.1.x snapshot.
> > 
> > 
> > On Thu, Feb 11, 2021 at 01:10:42PM +, Max R. Dechantsreiter wrote:
> >> I ran into a problem with 

Re: [OMPI users] GROMACS with openmpi

[Jeff Squyres (jsquyres) via users]

You might want to ask your question to the Gromacs community -- they can 
probably be more helpful than we can (we know little / nothing about Gromacs).

Good luck!



On Feb 11, 2021, at 10:46 AM, Wenhao Yao via users 
mailto:users@lists.open-mpi.org>> wrote:


Thanks for helping me though it a question out of topic,
   Could I know under which category should I 
run the given command from your side. For example under OPENMPI's or any of 
GROMACS...
Thanks for your attention, I appreciate any suggestions from your side.







Best,




On Thu, Feb 11, 2021 at 3:36 AM Gilles Gouaillardet via users 
mailto:users@lists.open-mpi.org>> wrote:

This is not an Open MPI question, and hence not a fit for this mailing list.



But here we go:

first, try

cmake -DGMX_MPI=ON ...

if it fails, try

cmake -DGMX_MPI=ON -DCMAKE_C_COMPILER=mpicc -DCMAKE_CXX_COMPILER=mpicxx ...



Cheers,



Gilles

- Original Message -

Hi, MPI developers and users,
   I want to run GROMACS using gmx_mpi rather than gmx, could you give 
me a hand on how to do that?
Thanks a lot!



Cheers,





--
Jeff Squyres
jsquy...@cisco.com

Re: [OMPI users] OpenMPI 4.1.0 misidentifies x86 capabilities

[Jeff Squyres (jsquyres) via users]

We did have some issues with 4.1.0 and AVX, but we have fixed everything that 
we were aware of.

I'd be curious to know if you still have build failures in the latest 4.1.x 
nightly snapshot.

If you do, can you send the following:

- stdout/stderr from running configure
- config.log
- stdout/stderr from running "make V=1" (for brevity, you can "make", get to 
the failure, and then "make V=1" to get just the details of the compile 
failure, vs. the details of the entire make with oodles of lengthy successful 
compiles)


> On Feb 11, 2021, at 9:15 AM, Max R. Dechantsreiter 
>  wrote:
> 
> ...The error that prompted me to start this thread occurred
> during "make all" with 4.1.0:
> 
> .
> .
> .
> Making all in mca/op/avx
> gmake[2]: Entering directory 
> `/home/maxd/XX/Build/openmpi-4.1.0_gcc-10.2.0/ompi/mca/op/avx'
>  CC   op_avx_component.lo
>  CC   liblocal_ops_avx_la-op_avx_functions.lo
>  CCLD liblocal_ops_avx.la
>  CC   liblocal_ops_avx512_la-op_avx_functions.lo
> op_avx_functions.c: In function 'ompi_op_avx_2buff_bxor_uint64_t_avx512':
> op_avx_functions.c:208:21: warning: AVX512F vector return without AVX512F 
> enabled changes the ABI [-Wpsabi]
>  208 | __m512i vecA =  _mm512_loadu_si512((__m512i*)in);  
>  \
>  | ^~~~
> op_avx_functions.c:263:5: note: in expansion of macro 'OP_AVX_AVX512_BIT_FUNC'
>  263 | OP_AVX_AVX512_BIT_FUNC(name, type_size, type, op); 
>  \
>  | ^~
> op_avx_functions.c:573:5: note: in expansion of macro 'OP_AVX_BIT_FUNC'
>  573 | OP_AVX_BIT_FUNC(bxor, 64, uint64_t, xor)
>  | ^~~
> In file included from 
> /home/maxd/XX/opt/gnu/gcc-10.2.0/lib/gcc/x86_64-linux-gnu/10.2.0/include/immintrin.h:55,
> from op_avx_functions.c:26:
> op_avx_functions.c: In function 'ompi_op_avx_2buff_max_int8_t_avx512':
> /home/maxd/XX/opt/gnu/gcc-10.2.0/lib/gcc/x86_64-linux-gnu/10.2.0/include/avx512fintrin.h:6429:1:
>  error: inlining failed in call to 'always_inline' '_mm512_storeu_si512': 
> target specific option mismatch
> 6429 | _mm512_storeu_si512 (void *__P, __m512i __A)
>  | ^~~
> op_avx_functions.c:73:13: note: called from here
>   73 | _mm512_storeu_si512((__m512*)out, res);
> \
>  | ^~
> op_avx_functions.c:124:5: note: in expansion of macro 'OP_AVX_AVX512_FUNC'
>  124 | OP_AVX_AVX512_FUNC(name, type_sign, type_size, type, op);  
> \
>  | ^~
> op_avx_functions.c:454:5: note: in expansion of macro 'OP_AVX_FUNC'
>  454 | OP_AVX_FUNC(max, i, 8,int8_t, max)
>  | ^~~
> In file included from 
> /home/maxd/XX/opt/gnu/gcc-10.2.0/lib/gcc/x86_64-linux-gnu/10.2.0/include/immintrin.h:65,
> from op_avx_functions.c:26:
> /home/maxd/XX/opt/gnu/gcc-10.2.0/lib/gcc/x86_64-linux-gnu/10.2.0/include/avx512bwintrin.h:1984:1:
>  error: inlining failed in call to 'always_inline' '_mm512_max_epi8': target 
> specific option mismatch
> 1984 | _mm512_max_epi8 (__m512i __A, __m512i __B)
>  | ^~~
> op_avx_functions.c:72:27: note: called from here
>   72 | __m512i res = _mm512_##op##_ep##type_sign##type_size(vecA, 
> vecB);  \
>  |   
> ^~
> op_avx_functions.c:124:5: note: in expansion of macro 'OP_AVX_AVX512_FUNC'
>  124 | OP_AVX_AVX512_FUNC(name, type_sign, type_size, type, op);  
> \
>  | ^~
> op_avx_functions.c:454:5: note: in expansion of macro 'OP_AVX_FUNC'
>  454 | OP_AVX_FUNC(max, i, 8,int8_t, max)
>  | ^~~
> In file included from 
> /home/maxd/XX/opt/gnu/gcc-10.2.0/lib/gcc/x86_64-linux-gnu/10.2.0/include/immintrin.h:55,
> from op_avx_functions.c:26:
> .
> .
> .
> 
> End result: the build failed.
> 
> My build of v4.1.x-202102090356-380ac96 threw no errors.
> I will continue with an attempt to build GROMACS using
> that 4.1.x snapshot.
> 
> 
> On Thu, Feb 11, 2021 at 01:10:42PM +, Max R. Dechantsreiter wrote:
>> I ran into a problem with 4.1.0 several weeks ago,
>> and no longer recall precisely how; I am now rebuilding
>> both 4.1.0 and a recent 4.1.x, then will use them to
>> build GROMACS, probably the application I was attemping
>> back then.
>> 
>> But I do have this from my notes (for 4.1.0):
>> 
>> mpicc -fopenmp hybrid_hello.c
>> export OMP_NUM_THREADS=2
>> mpirun -np 2 ./a.out
>> # [server.clearlight.us:18349] mca_base_component_repository_open: unable to 
>> open mca_op_avx: 
>> /home/maxd/XX/opt/gnu/openmpi-4.1.0_gcc-10.2.0/lib/openmpi/mca_op_avx.so:
>>  undefined symbol: ompi_op_avx_functions_avx512 (ignored)
>> # [server.clearlight.us:18348] 

Re: [OMPI users] GROMACS with openmpi

[Wenhao Yao via users]

Thanks for helping me though it a question out of topic,
   Could I know under which category should
I run the given command from your side. For example under OPENMPI's or any
of GROMACS...
Thanks for your attention, I appreciate any suggestions from your side.







Best,




On Thu, Feb 11, 2021 at 3:36 AM Gilles Gouaillardet via users <
users@lists.open-mpi.org> wrote:

> This is not an Open MPI question, and hence not a fit for this mailing
> list.
>
>
>
> But here we go:
>
> first, try
>
> cmake -DGMX_MPI=ON ...
>
> if it fails, try
>
> cmake -DGMX_MPI=ON -DCMAKE_C_COMPILER=mpicc -DCMAKE_CXX_COMPILER=mpicxx ...
>
>
>
> Cheers,
>
>
>
> Gilles
>
> - Original Message -
>
>
> Hi, MPI developers and users,
>I want to run GROMACS using *gmx_mpi* rather than *gmx*, could
> you give me a hand on how to do that?
> Thanks a lot!
>
>
>
> Cheers,
>
>
>
>
>

Re: [OMPI users] OpenMPI 4.1.0 misidentifies x86 capabilities

[Max R. Dechantsreiter via users]

...The error that prompted me to start this thread occurred
during "make all" with 4.1.0:

.
.
.
Making all in mca/op/avx
gmake[2]: Entering directory 
`/home/maxd/XX/Build/openmpi-4.1.0_gcc-10.2.0/ompi/mca/op/avx'
  CC   op_avx_component.lo
  CC   liblocal_ops_avx_la-op_avx_functions.lo
  CCLD liblocal_ops_avx.la
  CC   liblocal_ops_avx512_la-op_avx_functions.lo
op_avx_functions.c: In function 'ompi_op_avx_2buff_bxor_uint64_t_avx512':
op_avx_functions.c:208:21: warning: AVX512F vector return without AVX512F 
enabled changes the ABI [-Wpsabi]
  208 | __m512i vecA =  _mm512_loadu_si512((__m512i*)in);   
\
  | ^~~~
op_avx_functions.c:263:5: note: in expansion of macro 'OP_AVX_AVX512_BIT_FUNC'
  263 | OP_AVX_AVX512_BIT_FUNC(name, type_size, type, op);  
\
  | ^~
op_avx_functions.c:573:5: note: in expansion of macro 'OP_AVX_BIT_FUNC'
  573 | OP_AVX_BIT_FUNC(bxor, 64, uint64_t, xor)
  | ^~~
In file included from 
/home/maxd/XX/opt/gnu/gcc-10.2.0/lib/gcc/x86_64-linux-gnu/10.2.0/include/immintrin.h:55,
 from op_avx_functions.c:26:
op_avx_functions.c: In function 'ompi_op_avx_2buff_max_int8_t_avx512':
/home/maxd/XX/opt/gnu/gcc-10.2.0/lib/gcc/x86_64-linux-gnu/10.2.0/include/avx512fintrin.h:6429:1:
 error: inlining failed in call to 'always_inline' '_mm512_storeu_si512': 
target specific option mismatch
 6429 | _mm512_storeu_si512 (void *__P, __m512i __A)
  | ^~~
op_avx_functions.c:73:13: note: called from here
   73 | _mm512_storeu_si512((__m512*)out, res); 
   \
  | ^~
op_avx_functions.c:124:5: note: in expansion of macro 'OP_AVX_AVX512_FUNC'
  124 | OP_AVX_AVX512_FUNC(name, type_sign, type_size, type, op);   
   \
  | ^~
op_avx_functions.c:454:5: note: in expansion of macro 'OP_AVX_FUNC'
  454 | OP_AVX_FUNC(max, i, 8,int8_t, max)
  | ^~~
In file included from 
/home/maxd/XX/opt/gnu/gcc-10.2.0/lib/gcc/x86_64-linux-gnu/10.2.0/include/immintrin.h:65,
 from op_avx_functions.c:26:
/home/maxd/XX/opt/gnu/gcc-10.2.0/lib/gcc/x86_64-linux-gnu/10.2.0/include/avx512bwintrin.h:1984:1:
 error: inlining failed in call to 'always_inline' '_mm512_max_epi8': target 
specific option mismatch
 1984 | _mm512_max_epi8 (__m512i __A, __m512i __B)
  | ^~~
op_avx_functions.c:72:27: note: called from here
   72 | __m512i res = _mm512_##op##_ep##type_sign##type_size(vecA, 
vecB);  \
  |   
^~
op_avx_functions.c:124:5: note: in expansion of macro 'OP_AVX_AVX512_FUNC'
  124 | OP_AVX_AVX512_FUNC(name, type_sign, type_size, type, op);   
   \
  | ^~
op_avx_functions.c:454:5: note: in expansion of macro 'OP_AVX_FUNC'
  454 | OP_AVX_FUNC(max, i, 8,int8_t, max)
  | ^~~
In file included from 
/home/maxd/XX/opt/gnu/gcc-10.2.0/lib/gcc/x86_64-linux-gnu/10.2.0/include/immintrin.h:55,
 from op_avx_functions.c:26:
.
.
.

End result: the build failed.

My build of v4.1.x-202102090356-380ac96 threw no errors.
I will continue with an attempt to build GROMACS using
that 4.1.x snapshot.


On Thu, Feb 11, 2021 at 01:10:42PM +, Max R. Dechantsreiter wrote:
> I ran into a problem with 4.1.0 several weeks ago,
> and no longer recall precisely how; I am now rebuilding
> both 4.1.0 and a recent 4.1.x, then will use them to
> build GROMACS, probably the application I was attemping
> back then.
> 
> But I do have this from my notes (for 4.1.0):
> 
> mpicc -fopenmp hybrid_hello.c
> export OMP_NUM_THREADS=2
> mpirun -np 2 ./a.out
> # [server.clearlight.us:18349] mca_base_component_repository_open: unable to 
> open mca_op_avx: 
> /home/maxd/XX/opt/gnu/openmpi-4.1.0_gcc-10.2.0/lib/openmpi/mca_op_avx.so:
>  undefined symbol: ompi_op_avx_functions_avx512 (ignored)
> # [server.clearlight.us:18348] mca_base_component_repository_open: unable to 
> open mca_op_avx: 
> /home/maxd/XX/opt/gnu/openmpi-4.1.0_gcc-10.2.0/lib/openmpi/mca_op_avx.so:
>  undefined symbol: ompi_op_avx_functions_avx512 (ignored)
> # Hello from thread 0 out of 2 from process 0 out of 2 on server.clearlight.us
> # Hello from thread 1 out of 2 from process 0 out of 2 on server.clearlight.us
> # Hello from thread 0 out of 2 from process 1 out of 2 on server.clearlight.us
> # Hello from thread 1 out of 2 from process 1 out of 2 on server.clearlight.us
> 
> (where I X-ed out confidential details).  Not an error,
> but surely indicative of something amiss.
> 
> More to come!
> 
> 
> On Thu, Feb 11, 2021 at 02:02:48AM +, Jeff Squyres (jsquyres) via users 
> wrote:
> > 

Re: [OMPI users] OpenMPI 4.1.0 misidentifies x86 capabilities

[Max R. Dechantsreiter via users]

I ran into a problem with 4.1.0 several weeks ago,
and no longer recall precisely how; I am now rebuilding
both 4.1.0 and a recent 4.1.x, then will use them to
build GROMACS, probably the application I was attemping
back then.

But I do have this from my notes (for 4.1.0):

mpicc -fopenmp hybrid_hello.c
export OMP_NUM_THREADS=2
mpirun -np 2 ./a.out
# [server.clearlight.us:18349] mca_base_component_repository_open: unable to 
open mca_op_avx: 
/home/maxd/XX/opt/gnu/openmpi-4.1.0_gcc-10.2.0/lib/openmpi/mca_op_avx.so:
 undefined symbol: ompi_op_avx_functions_avx512 (ignored)
# [server.clearlight.us:18348] mca_base_component_repository_open: unable to 
open mca_op_avx: 
/home/maxd/XX/opt/gnu/openmpi-4.1.0_gcc-10.2.0/lib/openmpi/mca_op_avx.so:
 undefined symbol: ompi_op_avx_functions_avx512 (ignored)
# Hello from thread 0 out of 2 from process 0 out of 2 on server.clearlight.us
# Hello from thread 1 out of 2 from process 0 out of 2 on server.clearlight.us
# Hello from thread 0 out of 2 from process 1 out of 2 on server.clearlight.us
# Hello from thread 1 out of 2 from process 1 out of 2 on server.clearlight.us

(where I X-ed out confidential details).  Not an error,
but surely indicative of something amiss.

More to come!


On Thu, Feb 11, 2021 at 02:02:48AM +, Jeff Squyres (jsquyres) via users 
wrote:
> I think Max did try the latest 4.1 nightly build (from an off-list email), 
> and his problem still persisted.
> 
> Max: can you describe exactly how Open MPI failed?  All you said was:
> 
> >> Consequently AVX512 intrinsic functions were erroneously
> >> deployed, resulting in OpenMPI failure.
> 
> Can you provide more details?
> 
> 
> > On Feb 10, 2021, at 6:09 PM, Gilles Gouaillardet via users 
> >  wrote:
> > 
> > Max,
> > 
> > at configure time, Open MPI detects the *compiler* capabilities.
> > In your case, your compiler can emit AVX512 code.
> > (and fwiw, the tests are only compiled and never executed)
> > 
> > Then at *runtime*, Open MPI detects the *CPU* capabilities.
> > In your case, it should not invoke the functions containing AVX512 code.
> > 
> > That being said, several changes were made to the op/avx component,
> > so if you are experiencing some crashes, I do invite you to give a try to 
> > the
> > latest nightly snapshot for the v4.1.x branch.
> > 
> > 
> > Cheers,
> > 
> > Gilles
> > 
> > On Wed, Feb 10, 2021 at 10:43 PM Max R. Dechantsreiter via users
> >  wrote:
> >> 
> >> Configuring OpenMPI 4.1.0 with GCC 10.2.0 on
> >> Intel(R) Xeon(R) CPU E5-2620 v3, a Haswell processor
> >> that supports AVX2 but not AVX512, resulted in
> >> 
> >> checking for AVX512 support (no additional flags)... no
> >> checking for AVX512 support (with -march=skylake-avx512)... yes
> >> 
> >> in "configure" output, and in config.log
> >> 
> >> MCA_BUILD_ompi_op_has_avx512_support_FALSE='#'
> >> MCA_BUILD_ompi_op_has_avx512_support_TRUE=''
> >> 
> >> Consequently AVX512 intrinsic functions were erroneously
> >> deployed, resulting in OpenMPI failure.
> >> 
> >> The relevant test code was in essence
> >> 
> >> cat > conftest.c << EOF
> >> #include 
> >> 
> >> int main()
> >> {
> >>__m512 vA, vB;
> >> 
> >>_mm512_add_ps(vA, vB);
> >> 
> >>return 0;
> >> }
> >> EOF
> >> 
> >> The problem with this is that the result of the function
> >> is never used, so at optimization level higher than O0
> >> the compiler elimates the function as "dead code" (DCE).
> >> To wit,
> >> 
> >> gcc -O3 -march=skylake-avx512 -S conftest.c
> >> 
> >> yields
> >> 
> >>.file   "conftest.c"
> >>.text
> >>.section.text.startup,"ax",@progbits
> >>.p2align 4
> >>.globl  main
> >>.type   main, @function
> >> main:
> >> .LFB5345:
> >>.cfi_startproc
> >>xorl%eax, %eax
> >>ret
> >>.cfi_endproc
> >> .LFE5345:
> >>.size   main, .-main
> >>.ident  "GCC: (GNU) 10.2.0"
> >>.section.note.GNU-stack,"",@progbits
> >> 
> >> Compare this with the result of
> >> 
> >> gcc -O0 -march=skylake-avx512 -S conftest.c
> >> 
> >> in which the function IS called:
> >> 
> >>.file   "conftest.c"
> >>.text
> >>.globl  main
> >>.type   main, @function
> >> main:
> >> .LFB4092:
> >>.cfi_startproc
> >>pushq   %rbp
> >>.cfi_def_cfa_offset 16
> >>.cfi_offset 6, -16
> >>movq%rsp, %rbp
> >>.cfi_def_cfa_register 6
> >>andq$-64, %rsp
> >>subq$136, %rsp
> >>vmovaps 72(%rsp), %zmm0
> >>vmovaps %zmm0, -56(%rsp)
> >>vmovaps 8(%rsp), %zmm0
> >>vmovaps %zmm0, -120(%rsp)
> >>movl$0, %eax
> >>leave
> >>.cfi_def_cfa 7, 8
> >>ret
> >>.cfi_endproc
> >> .LFE4092:
> >>.size   main, .-main
> >>.ident  "GCC: (GNU) 10.2.0"
> >>.section.note.GNU-stack,"",@progbits
> >> 
> >> Note the use of a 512-bit 

Re: [OMPI users] GROMACS with openmpi

[Gilles Gouaillardet via users]

This is not an Open MPI question, and hence not a fit for this mailing 
list.



But here we go:

first, try

cmake -DGMX_MPI=ON ...

if it fails, try

cmake -DGMX_MPI=ON -DCMAKE_C_COMPILER=mpicc -DCMAKE_CXX_COMPILER=mpicxx .
..



Cheers,



Gilles 

- Original Message -


Hi, MPI developers and users,
   I want to run GROMACS using gmx_mpi rather than gmx, could 
you give me a hand on how to do that? 
Thanks a lot!



Cheers,