Hello, I've been having trouble for awhile now running some OpenMPI+IB jobs on multiple tasks. The problems are all "hangs" and are not reproducible - the same execution started again will in general proceed just fine where previously it got stuck, but then later get stuck. These stuck processes are pegged at 100% CPU usage and remain there for days if not killed.
The same nature of problem exists in oMPI 1.2.5, 1.4.2, and 1.5.3 (for the code I am running). This is quite possible some problem in the configuration/cluster, I am not claiming that it is a bug in oMPI, but was just hopeful that someone might have a guess as to what is going on. In ancient 1.2.5 the problem manifests as (I attach gdb to the stalled process on one of the child nodes): -------------------------------------------------------------------- (gdb) bt #0 0x00002b8135b3f699 in ibv_cmd_create_qp () from /usr/lib64/libmlx4-rdmav2.so #1 0x00002b8135b3faa6 in ibv_cmd_create_qp () from /usr/lib64/libmlx4-rdmav2.so #2 0x00002b813407bff1 in btl_openib_component_progress () from /n/sw/openmpi-1.2.5-gcc-4.1.2/lib/openmpi/mca_btl_openib.so #3 0x00002b8133e6f04a in mca_bml_r2_progress () from /n/sw/openmpi-1.2.5-gcc-4.1.2/lib/openmpi/mca_bml_r2.so #4 0x00002b812f52c9ba in opal_progress () from /n/sw/openmpi-1.2.5-gcc-4.1.2/lib64/libopen-pal.so.0 #5 0x00002b812f067b05 in ompi_request_wait_all () from /n/sw/openmpi-1.2.5-gcc-4.1.2/lib64/libmpi.so.0 #6 0x0000000000000000 in ?? () (gdb) next Single stepping until exit from function ibv_cmd_create_qp, which has no line number information. 0x00002b8135b3f358 in pthread_spin_unlock@plt () from /usr/lib64/libmlx4-rdmav2.so (gdb) next Single stepping until exit from function pthread_spin_unlock@plt, which has no line number information. 0x00000038c860b760 in pthread_spin_unlock () from /lib64/libpthread.so.0 (gdb) next Single stepping until exit from function pthread_spin_unlock, which has no line number information. 0x00002b8135b3fc21 in ibv_cmd_create_qp () from /usr/lib64/libmlx4-rdmav2.so (gdb) next Single stepping until exit from function ibv_cmd_create_qp, which has no line number information. 0x00002b813407bff1 in btl_openib_component_progress () from /n/sw/openmpi-1.2.5-gcc-4.1.2/lib/openmpi/mca_btl_openib.so (gdb) next Single stepping until exit from function btl_openib_component_progress, which has no line number information. 0x00002b8133e6f04a in mca_bml_r2_progress () from /n/sw/openmpi-1.2.5-gcc-4.1.2/lib/openmpi/mca_bml_r2.so (gdb) next Single stepping until exit from function mca_bml_r2_progress, which has no line number information. 0x00002b812f52c9ba in opal_progress () from /n/sw/openmpi-1.2.5-gcc-4.1.2/lib64/libopen-pal.so.0 (gdb) next Single stepping until exit from function opal_progress, which has no line number information. 0x00002b812f067b05 in ompi_request_wait_all () from /n/sw/openmpi-1.2.5-gcc-4.1.2/lib64/libmpi.so.0 (gdb) next Single stepping until exit from function ompi_request_wait_all, which has no line number information. ---hang--- (infinite loop?) On a different task: 0x00002ba2383b4982 in opal_progress () from /n/sw/openmpi-1.2.5-gcc-4.1.2/lib64/libopen-pal.so.0 (gdb) bt #0 0x00002ba2383b4982 in opal_progress () from /n/sw/openmpi-1.2.5-gcc-4.1.2/lib64/libopen-pal.so.0 #1 0x00002ba237eefb05 in ompi_request_wait_all () from /n/sw/openmpi-1.2.5-gcc-4.1.2/lib64/libmpi.so.0 #2 0x0000000000000000 in ?? () (gdb) next Single stepping until exit from function opal_progress, which has no line number information. 0x00002ba237eefb05 in ompi_request_wait_all () from /n/sw/openmpi-1.2.5-gcc-4.1.2/lib64/libmpi.so.0 (gdb) next Single stepping until exit from function ompi_request_wait_all, which has no line number information. ---hang--- -------------------------------------------------------------------- On 1.5.3 a similar "hang" problem happens but the backtrace goes back to the original code call which is a MPI_Sendrecv(): -------------------------------------------------------------------- 3510 OPAL_THREAD_UNLOCK(&endpoint->eager_rdma_local.lock); (gdb) bt #0 progress_one_device () at btl_openib_component.c:3510 #1 btl_openib_component_progress () at btl_openib_component.c:3541 #2 0x00002b722f348b35 in opal_progress () at runtime/opal_progress.c:207 #3 0x00002b722f287025 in opal_condition_wait (buf=0x2aaaab636298, count=251328, datatype=0x6ef240, dst=12, tag=35, sendmode=MCA_PML_BASE_SEND_STANDARD, comm=0x6ee430) at ../../../../opal/threads/condition.h:99 #4 ompi_request_wait_completion (buf=0x2aaaab636298, count=251328, datatype=0x6ef240, dst=12, tag=35, sendmode=MCA_PML_BASE_SEND_STANDARD, comm=0x6ee430) at ../../../../ompi/request/request.h:377 #5 mca_pml_ob1_send (buf=0x2aaaab636298, count=251328, datatype=0x6ef240, dst=12, tag=35, sendmode=MCA_PML_BASE_SEND_STANDARD, comm=0x6ee430) at pml_ob1_isend.c:125 #6 0x00002b722f1cb568 in PMPI_Sendrecv (sendbuf=0x2aaba9587398, sendcount=251328, sendtype=0x6ef240, dest=12, sendtag=35, recvbuf=0x2aaba7a555f8, recvcount=259008, recvtype=0x6ef240, source=12, recvtag=35, comm=0x6ee430, status=0x6f2160) at psendrecv.c:84 #7 0x0000000000472fd5 in voronoi_ghost_search (T=0xf70b40) at voronoi_ghost_search.c:190 #8 0x00000000004485c6 in create_mesh () at voronoi.c:107 #9 0x0000000000411b1c in run () at run.c:215 #10 0x0000000000410d8a in main (argc=3, argv=0x7fff3fc25948) at main.c:190 (gdb) next 3466 for(i = 0; i < c; i++) { (gdb) next 3467 endpoint = device->eager_rdma_buffers[i]; (gdb) next 3469 if(!endpoint) (gdb) next 3472 OPAL_THREAD_LOCK(&endpoint->eager_rdma_local.lock); (gdb) next 3473 frag = MCA_BTL_OPENIB_GET_LOCAL_RDMA_FRAG(endpoint, (gdb) next 3476 if(MCA_BTL_OPENIB_RDMA_FRAG_LOCAL(frag)) { (gdb) next 3510 OPAL_THREAD_UNLOCK(&endpoint->eager_rdma_local.lock); -------------------------------------------------------------------- The OS is: Linux version 2.6.18-194.32.1.el5 (mockbu...@builder10.centos.org) (gcc version 4.1.2 20080704 (Red Hat 4.1.2-48)) The output from ibv_devinfo: -------------------------------------------------------------------- hca_id: mlx4_0 transport: InfiniBand (0) fw_ver: 2.5.000 node_guid: 0018:8b90:97fe:2149 sys_image_guid: 0018:8b90:97fe:214c vendor_id: 0x02c9 vendor_part_id: 25418 hw_ver: 0xA0 board_id: DEL08C0000001 phys_port_cnt: 2 port: 1 state: PORT_ACTIVE (4) max_mtu: 2048 (4) active_mtu: 2048 (4) sm_lid: 2 port_lid: 166 port_lmc: 0x00 port: 2 state: PORT_DOWN (1) max_mtu: 2048 (4) active_mtu: 2048 (4) sm_lid: 0 port_lid: 0 port_lmc: 0x00 -------------------------------------------------------------------- I am no MPI expert but just hopeful of any suggestions. Thanks! Dylan Nelson