[OMPI devel] Valgrind warning in MPI_Win_allocate[_shared]()
Just built 1.8.3 for another round of testing with mpi4py. I'm getting
the following valgrind warning:
==4718== Conditional jump or move depends on uninitialised value(s)
==4718==at 0xD0D9F4C: component_select (osc_sm_component.c:333)
==4718==by 0x4CF44F6: ompi_osc_base_select (osc_base_init.c:73)
==4718==by 0x4C68B69: ompi_win_allocate (win.c:182)
==4718==by 0x4CBB8C2: PMPI_Win_allocate (pwin_allocate.c:79)
==4718==by 0x400898: main (in /home/dalcinl/Devel/BUGS-MPI/openmpi/a.out)
The offending code is in ompi/mca/osc/sm/osc_sm_component.c, it seems
you forgot to initialize the "blocking_fence" to a default true or
false value.
bool blocking_fence;
int flag;
if (OMPI_SUCCESS != ompi_info_get_bool(info, "blocking_fence",
&blocking_fence, &flag)) {
goto error;
}
if (blocking_fence) {
--
Lisandro Dalcin
Research Scientist
Computer, Electrical and Mathematical Sciences & Engineering (CEMSE)
Numerical Porous Media Center (NumPor)
King Abdullah University of Science and Technology (KAUST)
http://numpor.kaust.edu.sa/
4700 King Abdullah University of Science and Technology
al-Khawarizmi Bldg (Bldg 1), Office # 4332
Thuwal 23955-6900, Kingdom of Saudi Arabia
http://www.kaust.edu.sa
Office Phone: +966 12 808-0459
Re: [OMPI devel] Different behaviour with MPI_IN_PLACE in MPI_Reduce_scatter() and MPI_Ireduce_scatter()
On 22 April 2014 03:02, George Bosilca wrote: > Btw, the proposed validator was incorrect the first printf instead of > > printf(“[%d] rbuf[%d]=%2d expected:%2d\n”, rank, 0, recvbuf[i], size); > > should be > > printf(“[%d] rbuf[%d]=%2d expected:%2d\n”, rank, 0, recvbuf[0], size); > I'm testing this with 1.8.3 after fixed the my incorrect printf, and still get different results (and the nbcoll one is wrong) using one process (for two or more everything's OK). $ mpicc -DNBCOLL=0 ireduce_scatter.c && mpiexec -n 1 ./a.out [0] rbuf[0]= 1 expected: 1 $ mpicc -DNBCOLL=1 ireduce_scatter.c && mpiexec -n 1 ./a.out [0] rbuf[0]=60 expected: 1 -- Lisandro Dalcin Research Scientist Computer, Electrical and Mathematical Sciences & Engineering (CEMSE) Numerical Porous Media Center (NumPor) King Abdullah University of Science and Technology (KAUST) http://numpor.kaust.edu.sa/ 4700 King Abdullah University of Science and Technology al-Khawarizmi Bldg (Bldg 1), Office # 4332 Thuwal 23955-6900, Kingdom of Saudi Arabia http://www.kaust.edu.sa Office Phone: +966 12 808-0459
Re: [OMPI devel] Neighbor collectives with periodic Cartesian topologies of size one
On 25 September 2014 20:50, Nathan Hjelm wrote:
> On Tue, Aug 26, 2014 at 07:03:24PM +0300, Lisandro Dalcin wrote:
>> I finally managed to track down some issues in mpi4py's test suite
>> using Open MPI 1.8+. The code below should be enough to reproduce the
>> problem. Run it under valgrind to make sense of my following
>> diagnostics.
>>
>> In this code I'm creating a 2D, periodic Cartesian topology out of
>> COMM_SELF. In this case, the process in COMM_SELF has 4 logical in/out
>> links to itself. So we have size=1 but indegree=outdegree=4. However,
>> in ompi/mca/coll/basic/coll_basic_module.c, "size * 2" request are
>> being allocated to manage communication:
>>
>> if (OMPI_COMM_IS_INTER(comm)) {
>> size = ompi_comm_remote_size(comm);
>> } else {
>> size = ompi_comm_size(comm);
>> }
>> basic_module->mccb_num_reqs = size * 2;
>> basic_module->mccb_reqs = (ompi_request_t**)
>> malloc(sizeof(ompi_request_t *) * basic_module->mccb_num_reqs);
>>
>> I guess you have to also special-case for topologies and allocate
>> indegree+outdegree requests (not sure about this number, just
>> guessing).
>>
>
> I wish this was possible but the topology information is not available
> at that point. We may be able to change that but I don't see the work
> completing anytime soon. I committed an alternative fix as r32796 and
> CMR'd it to 1.8.3. I can confirm that the attached reproducer no longer
> produces a SEGV. Let me know if you run into any more issues.
>
Did your fix get in for 1.8.3? I'm still getting the segfault.
--
Lisandro Dalcin
Research Scientist
Computer, Electrical and Mathematical Sciences & Engineering (CEMSE)
Numerical Porous Media Center (NumPor)
King Abdullah University of Science and Technology (KAUST)
http://numpor.kaust.edu.sa/
4700 King Abdullah University of Science and Technology
al-Khawarizmi Bldg (Bldg 1), Office # 4332
Thuwal 23955-6900, Kingdom of Saudi Arabia
http://www.kaust.edu.sa
Office Phone: +966 12 808-0459
Re: [OMPI devel] Different behaviour with MPI_IN_PLACE in MPI_Reduce_scatter() and MPI_Ireduce_scatter()
Lisandro, Good catch. Indeed the MPI_Ireduce_scatter was not covering the case where MPI_IN_PLACE was used over a communicator with a single participant. I pushed a patch and schedule it for 1.8.4. Check https://svn.open-mpi.org/trac/ompi/ticket/4924 for more info. Thanks, George. On Sun, Sep 28, 2014 at 6:29 AM, Lisandro Dalcin wrote: > On 22 April 2014 03:02, George Bosilca wrote: > > Btw, the proposed validator was incorrect the first printf instead of > > > > printf(“[%d] rbuf[%d]=%2d expected:%2d\n”, rank, 0, recvbuf[i], size); > > > > should be > > > > printf(“[%d] rbuf[%d]=%2d expected:%2d\n”, rank, 0, recvbuf[0], size); > > > > I'm testing this with 1.8.3 after fixed the my incorrect printf, and > still get different results (and the nbcoll one is wrong) using one > process (for two or more everything's OK). > > $ mpicc -DNBCOLL=0 ireduce_scatter.c && mpiexec -n 1 ./a.out > [0] rbuf[0]= 1 expected: 1 > > $ mpicc -DNBCOLL=1 ireduce_scatter.c && mpiexec -n 1 ./a.out > [0] rbuf[0]=60 expected: 1 > > > -- > Lisandro Dalcin > > Research Scientist > Computer, Electrical and Mathematical Sciences & Engineering (CEMSE) > Numerical Porous Media Center (NumPor) > King Abdullah University of Science and Technology (KAUST) > http://numpor.kaust.edu.sa/ > > 4700 King Abdullah University of Science and Technology > al-Khawarizmi Bldg (Bldg 1), Office # 4332 > Thuwal 23955-6900, Kingdom of Saudi Arabia > http://www.kaust.edu.sa > > Office Phone: +966 12 808-0459 >
