Nathan,
Thanks for your response.
Yes. My previous mail was the result of uncommented code.
Now I also pulled latest varList source code which uncommented
the section you mentioned, but the result was same.
If MPI_T_cvar_get_info should return MPI_T_ERR_INVALID_INDEX
for variables for unloaded components, not returning
MPI_T_ERR_INVALID_INDEX is the problem.
I run varList on GDB and found that MPI_T_cvar_get_info returns
MPI_T_ERR_INVALID_INDEX for shmem_sysv_priority (this is sane).
But it returns MPI_SUCCESS for shmem_sysv_major_version.
The difference is mbv_flags values. mbv_flags is 0x44 for
shmem_sysv_priority on MPI_T_cvar_get_info call so that
mca_base_var_get function in opal/mca/base/mca_base_var.c
returns OPAL_ERR_NOT_FOUND. But mbv_flags is 0x10003 for
shmem_sysv_major_version so that mca_base_var_get function
returns OPAL_SUCCESS.
Control variables for unloaded components are not deregistered
completely?
I can track it more when I have time.
My environment:
OS: Debian GNU/Linux wheezy
CPU: x86_64
Run: mpiexec -n 1 varList
Open MPI source: trunk r32338 (almost latest)
Open MPI configure:
enable_picky=yes
enable_debug=yes
enable_mem_debug=yes
enable_mem_profile=yes
enable_memchecker=no
enable_mca_no_build=btl-elan,btl-gm,btl-mx,btl-ofud,btl-portals,btl-sctp,btl-template,btl-udapl,common-mx,common-portals,ess-alps,ess-cnos,ess-lsf,ess-portals_utcp,ess-singleton,ess-slurm,grpcomm-cnos,mpool-fake,mtl,notifier,plm-alps,plm-ccp,plm-lsf,plm-process,plm-slurm,plm-submit,plm-tm,plm-xgrid,pml-cm,pml-csum,pml-example,pml-v,ras
enable_contrib_no_build=vt
enable_mpi_cxx=no
enable_mpi_f77=no
enable_mpi_f90=no
enable_ipv6=no
enable_mpi_io=no
with_devel_headers=no
with_wrapper_cflags=-g
with_wrapper_cxxflags=-g
with_wrapper_fflags=-g
with_wrapper_fcflags=-g
Regards,
KAWASHIMA Takahiro
> The problem is the code in question does not check the return code of
> MPI_T_cvar_handle_alloc . We are returning an error and they still try
> to use the handle (which is stale). Uncomment this section of the code:
>
>
> //if (MPI_T_ERR_INVALID_INDEX == err)// { NOTE TZI: This
> variable is not recognized by Mvapich. It is OpenMPI specific.
> // continue;
>
>
> Note that MPI_T_ERR_INVALID_INDEX is in the MPI-3 standard but mvapich
> must not have implemented it (and thus should not claim to be MPI 3.0).
>
> -Nathan
>
> On Wed, Jul 30, 2014 at 12:04:55AM +0900, KAWASHIMA Takahiro wrote:
> > Hi,
> >
> > I encountered the same SEGV reported on the users list when
> > running varList program.
> >
> > http://www.open-mpi.org/community/lists/users/2014/07/24792.php
> >
> > mpiexec -n 1 ./varList:
> > ----------------------------------------------------------------
> > ... snip ...
> > event U/D-2 CHAR n/a ALL
> > event_base_verbose D/D-8 INT n/a
> > LOCAL 0
> > event_libevent2021_event_include U/A-3 CHAR n/a
> > LOCAL poll
> > opal_event_include U/A-3 CHAR n/a
> > LOCAL poll
> > event_libevent2021_major_version D/A-9 INT n/a
> > UNKNOWN 1
> > event_libevent2021_minor_version D/A-9 INT n/a
> > UNKNOWN 9
> > event_libevent2021_release_version D/A-9 INT n/a
> > UNKNOWN 0
> > shmem U/D-2 CHAR n/a ALL
> > shmem_base_verbose D/D-8 INT n/a
> > LOCAL 0
> > shmem_base_RUNTIME_QUERY_hint D/A-9 CHAR n/a
> > ALL-EQ
> > shmem_mmap_priority U/A-3 INT n/a ALL
> > 50
> > shmem_mmap_enable_nfs_warning D/A-9 INT n/a
> > LOCAL true
> > shmem_mmap_relocate_backing_file D/A-9 INT n/a ALL
> > 0
> > shmem_mmap_backing_file_base_dir D/A-9 CHAR n/a ALL
> > /dev/shm
> > shmem_mmap_major_version D/A-9 INT n/a
> > UNKNOWN 1
> > shmem_mmap_minor_version D/A-9 INT n/a
> > UNKNOWN 9
> > shmem_mmap_release_version D/A-9 INT n/a
> > UNKNOWN 0
> > shmem_posix_major_version D/A-9 INT n/a
> > UNKNOWN 1201644720
> > shmem_posix_minor_version D/A-9 INT n/a
> > UNKNOWN 32756
> > shmem_posix_release_version D/A-9 INT n/a
> > UNKNOWN 6
> > [ppc:12688] *** Process received signal ***
> > [ppc:12688] Signal: Segmentation fault (11)
> > [ppc:12688] Signal code: Invalid permissions (2)
> > [ppc:12688] Failing at address: 0x7ff4479f83d8
> > [ppc:12688] [ 0] /lib/x86_64-linux-gnu/libc.so.6(+0x325c0)[0x7ff4493015c0]
> > [ppc:12688] [ 1]
> > /home/rivis/opt/openmpi-trunk-debug/lib/libmpi.so.0(PMPI_T_cvar_read+0xbc)[0x7ff44970abb7]
> > [ppc:12688] [ 2] ./varlist(list_cvars+0x56a)[0x4029bc]
> > [ppc:12688] [ 3] ./varlist(main+0x42b)[0x403598]
> > [ppc:12688] [ 4]
> > /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xfd)[0x7ff4492edeed]
> > [ppc:12688] [ 5] ./varlist[0x4016c9]
> > [ppc:12688] *** End of error message ***
> > ----------------------------------------------------------------
> >
> > I tracked this error and found that this seems related to DSO.
> >
> > The error occurs when accessing value->intval for the
> > control variable shmem_sysv_major_version in MPI_T_cvar_read.
> >
> > https://svn.open-mpi.org/trac/ompi/browser/trunk/ompi/mpi/tool/cvar_read.c
> >
> > The 'value' was gotten by mca_base_var_get_value and it points
> > mca_shmem_sysv_component.super.base_version.mca_component_major_version,
> > which was dlclose'd in MPI_INIT for DSO.
> > (component mmap is selected on my environment)
> >
> > Abnormal shmem_posix_{major,minor,relase}_version values in
> > my output above are the same reason. SEGV occurs if the memory
> > was returned to kernel, and abnormal values are printed
> > if not yet.
> >
> > So this SEGV doesn't occur if I configure Open MPI with
> > --disable-dlopen option. I think it's the reason why Nathan
> > doesn't see this error.
