Dear Open MPI developer,
we have both Open MPI 1.6(.5) and 1.8(.3) in our cluster, configured to be used with Platform LSF.
One of our users run into an issue when trying to link his code (combination of lex/C and Fortran) with v.1.8, whereby with OpenMPI/1.6er the code can be linked OK.
> $ make
> mpif90 -c main.f90
> yacc -d example4.y
> mpicc -c y.tab.c
> mpicc -c mymain.c
> lex example4.l
> mpicc -c lex.yy.c
> mpif90 -o example main.o y.tab.o mymain.o lex.yy.o
> ld: y.tab.o(.text+0xd9): unresolvable R_X86_64_PC32 relocation against symbol `yylval'
> ld: y.tab.o(.text+0x16f): unresolvable R_X86_64_PC32 relocation against symbol `yyval'
> .......
looking into "mpif90 --show-me" let us see that the link line and possibly the philosophy behind it has been changed, there is also a note on it:
# Note that per
https://svn.open-mpi.org/trac/ompi/ticket/3422, we
# intentionally only link in the MPI libraries (ORTE, OPAL, etc. are
# pulled in implicitly) because we intend MPI applications to only use
# the MPI API.
Well, by now we know two workarounds:
a) add "-lbat -llsf" to the link line
b) add " -Wl,--as-needed" to the link line
What would be better? Maybe one of this should be added to linker_flags=..." in the .../share/openmpi/mpif90-wrapper-data.txt file? As of the note above, (b) would be better?
Best
Paul Kapinos
P.S. $ mpif90 --show-me
1.6.5
ifort -nofor-main -I/opt/MPI/openmpi-1.6.5/linux/intel/include -fexceptions -I/opt/MPI/openmpi-1.6.5/linux/intel/lib -L/opt/lsf/9.1/linux2.6-glibc2.3-x86_64/lib -L/opt/MPI/openmpi-1.6.5/linux/intel/lib -lmpi_f90 -lmpi_f77 -lmpi -losmcomp -lrdmacm -libverbs -lrt -lnsl -lutil -lpsm_infinipath -lbat -llsf -ldl -lm -lnuma -lrt -lnsl -lutil
1.8.3
ifort -I/opt/MPI/openmpi-1.8.3/linux/intel/include -fexceptions -I/opt/MPI/openmpi-1.8.3/linux/intel/lib -L/opt/lsf/9.1/linux2.6-glibc2.3-x86_64/lib -Wl,-rpath -Wl,/opt/lsf/9.1/linux2.6-glibc2.3-x86_64/lib -Wl,-rpath -Wl,/opt/MPI/openmpi-1.8.3/linux/intel/lib -Wl,--enable-new-dtags -L/opt/MPI/openmpi-1.8.3/linux/intel/lib -lmpi_usempif08 -lmpi_usempi_ignore_tkr -lmpi_mpifh -lmpi
P.S.2 $ man ld
....
--as-needed
--no-as-needed
This option affects ELF DT_NEEDED tags for dynamic libraries
mentioned on the command line after the --as-needed option.
Normally the linker will add a DT_NEEDED tag for each dynamic
library mentioned on the command line, regardless of whether the
library is actually needed or not. --as-needed causes a DT_NEEDED
tag to only be emitted for a library that satisfies an undefined
symbol reference from a regular object file or, if the library is
not found in the DT_NEEDED lists of other libraries linked up to
that point, an undefined symbol reference from another dynamic
library. --no-as-needed restores the default behaviour.
....
--
Dipl.-Inform. Paul Kapinos - High Performance Computing,
RWTH Aachen University, IT Center
Seffenter Weg 23, D 52074 Aachen (Germany)
Tel: +49 241/80-24915
