On 1/25/2013 12:19 PM, Steve Wise wrote:
Hello,
I'm tracking an issue I see in openmpi-1.6.3. Running this command on
my chelsio iwarp/rdma setup causes a seg fault every time:
/usr/mpi/gcc/openmpi-1.6.3-dbg/bin/mpirun --np 2 --host
hpc-hn1,hpc-cn2 --mca btl openib,sm,self --mca
btl_openib_ipaddr_include "192.168.170.0/24"
/usr/mpi/gcc/openmpi-1.6.3/tests/IMB-3.2/IMB-MPI1 pingpong
The segfault is during finalization, and I've debugged this to the
point were I see a call to dereg_mem() after the openib blt is
unloaded via dlclose(). dereg_mem() dereferences a function pointer
to call the btl-specific dereg function, in this case it is
openib_dereg_mr(). However, since that btl has already been unloaded,
the deref causes a seg fault. Happens every time with the above mpi job.
Now, I tried this same experiment with openmpi-1.7rc6 and I don't see
the seg fault, and I don't see a call to dereg_mem() after the openib
btl is unloaded. That's all well good. :) But I'd like to get this
fix pushed into 1.6 since that is the current stable release.
Question: Can someone point me to the fix in 1.7?
Thanks,
Steve.
It appears that in ompi_mpi_finalize(), mca_pml_base_close() is called
which unloads the openib btl. Then further down in ompi_mpi_finalize(),
mca_mpool_base_close() is called which ends up calling dereg_mem() which
seg faults trying to call into the unloaded openib btl.
Anybody have thoughts? Anybody care? :)
Steve.
