On 13 August 2010 05:22, Matthias Jurenz <matthias.jur...@tu-dresden.de> wrote: > On Wednesday 11 August 2010 23:16:50 Lisandro Dalcin wrote: >> On 11 August 2010 03:12, Matthias Jurenz <matthias.jur...@tu-dresden.de> > wrote: >> > Hello Lisandro, >> > >> > this problem will be fixed in the next Open MPI release. There was an >> > obsolete preprocessor condition around the MPI_Init_thread wrapper, so >> > the source code could never be compiled :-( >> > >> > Thanks for the hint. >> > >> > Matthias >> >> OK. Many thanks for you clarification. >> >> BTW, I have and additional issue. I'm trying to build as shared >> library from libvt*.a using by passing -whole-archive to the linker. >> The idea behind this is to use that library with LD_PRELOAD to get MPI >> tracing of a binary compiled with plain mpicc (i.e, not mpicc-vt). For >> example, I managed to get this trick working with MPE. Moreover, I can >> enable MPI profiling at runtime in a Python script using mpi4pt by >> dlopen'ing the shared lib with profiling symbols before loading the >> mpi4py.MPI Python extension module. Being able to profile without a >> recompile is nice ;-) >> >> However, see this: >> >> $ pwd >> /usr/local/openmpi/1.4.2/lib >> >> $ ll libvt* >> -rw-r--r--. 1 root root 410784 2010-05-05 20:40 libvt.a >> -rw-r--r--. 1 root root 197618 2010-05-05 20:40 libvt.fmpi.a >> -rw-r--r--. 1 root root 569128 2010-05-05 20:40 libvt.mpi.a >> -rw-r--r--. 1 root root 503514 2010-05-05 20:40 libvt.omp.a >> -rw-r--r--. 1 root root 661466 2010-05-05 20:40 libvt.ompi.a >> >> $ nm libvt* | grep pomp_rd_table >> U pomp_rd_table >> U pomp_rd_table >> U pomp_rd_table >> U pomp_rd_table >> U pomp_rd_table >> U pomp_rd_table >> U pomp_rd_table >> U pomp_rd_table >> U pomp_rd_table >> U pomp_rd_table >> >> That symbol (and possibly others) are undefined and I cannot found >> them elsewhere. Is there any easy way to build a shared lib with the >> MPI_xxx symbols? >> > > Actually, the symbols above will be defined at compile/link time of the > application by the OpenMP instrumentor "OPARI". > However, while your application doesn't use OpenMP it should work to define > the > missing symbols in a separate source file (see attachment) when building the > shared library: > > gcc -fPIC -I<mpi-includedir>/vampirtrace -shared missing_syms.c -o > libvt.mpi.so -Wl,--whole-archive <mpi-libdir>/libvt.mpi.a <mpi- > libdir>/libotf.a -Wl,--no-whole-archive -ldl -lz -L<mpi-libdir> -lmpi >
OK. Many thanks for the hint. I was able to build a shared lib, dlopen() it at runtime and get MPI traces from Python scripts without need of recompiles with mpicc-vt. Sweet! > FYI, the next Open MPI 1.5 will come with a newer VampirTrace which provides > shared libraries by default. > Nice! ... Perhaps Open MPI mpiexec's could gain a -vt flag to enable traces at runtime (should be easy to implement with LD_PRELOAD, right?)... BTW, I understand Open MPI 1.5 VT will have the MPI_Init_thread() issue fixed. Any chance for v1.4 series? -- Lisandro Dalcin --------------- CIMEC (INTEC/CONICET-UNL) Predio CONICET-Santa Fe Colectora RN 168 Km 472, Paraje El Pozo Tel: +54-342-4511594 (ext 1011) Tel/Fax: +54-342-4511169
