[mvapich-discuss] mvapich2-1.4 bug for profiling tool.

[chan at mcs.anl.gov]

My subscription to mvapich-discuss may have problem, so
cc to panda just in case.

Attached is a patch against mvapich2-1.4 that replaces
the MPI calls by its PMPI calls counterpart.  Without
the patch, any MPE logging application (i.e. created
by "mpicc -mpe=mpilog") that makes MPI_Comm_split(),
MPI_Comm_dup() and MPI_Comm_create() will fail with
following backtrace.  The following is a simple
MPI program distributed with MPICH2/MPE

.../examples_logging> mpiexec -n 4 comm1_isr | & ~/bin/bt2line comm1_isr
......
	At [1]: comm1_isr(CLOG_CommSet_get_IDs+0x5c)[/scratch/jhedden/build/mvapich2/mvapich2-1.4/src/mpe2/src/logging/src/clog_commset.c:466]
	At [2]: comm1_isr(MPI_Comm_test_inter+0xc9)[/scratch/jhedden/build/mvapich2/mvapich2-1.4/src/mpe2/src/wrappers/src/log_mpi_core.c:2698]
	At [3]: comm1_isr(PMPI_Comm_split+0x917)[/scratch/jhedden/build/mvapich2/mvapich2-1.4/src/mpi/comm/comm_split.c:423]
	At [4]: comm1_isr(MPI_Comm_split+0x10e)[/scratch/jhedden/build/mvapich2/mvapich2-1.4/src/mpe2/src/wrappers/src/log_mpi_core.c:2668]
	At [5]: comm1_isr(main+0x182)[/scratch/chan/mpe_work/examples_logging/comm1_isr.c:43]
	At [6]: /lib64/libc.so.6(__libc_start_main+0xf4)[??:0]
	At [7]: comm1_isr[??:0]
......

This affects not only MPE but also other profiling tools.
Without the patch, it could lead to circular profiling
that some profiling tools can't easily handle.  Some workaround
exists in certain situations, but the workaround will have
performance penalty for profiling tools, so MPE that is distributed
with MPICH2 assumes MPI implementation cares about performance and
does not make MPI calls within the implementation, hence the error
we see here.

Hope mvapich team will include the patch in their future release,
i.e. uses PMPI calls instead of MPI calls in the future update.

Thanks,
A.Chan
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