Are your processes places the same way with the two MPI implementations? Per-node vs. per-core ?
george. On Dec 20, 2010, at 11:14 , Gilbert Grosdidier wrote: > Bonjour, > > I am now at a loss with my running of OpenMPI (namely 1.4.3) > on a SGI Altix cluster with 2048 or 4096 cores, running over Infiniband. > > After fixing several rather obvious failures with Ralph, Jeff and John help, > I am now facing the bottom of this story since : > - there are no more obvious failures with messages > - compared to the running of the application with SGI-MPT, the CPU > performances I get > are very low, decreasing when the number of cores increases (cf below) > - these performances are highly reproducible > - I tried a very high number of -mca parameters, to no avail > > If I take as a reference the MPT CPU speed performance, > it is of about 900 (in some arbitrary unit), whatever the > number of cores I used (up to 8192). > > But, when running with OMPI, I get: > - 700 with 1024 cores (which is already rather low) > - 300 with 2048 cores > - 60 with 4096 cores. > > The computing loop, over which the above CPU performance is evaluated, > includes > a stack of MPI exchanges [per core : 8 x (MPI_Isend + MPI_Irecv) + > MPI_Waitall] > > The application is of the 'domain partition' type, > and the performances, together with the memory footprint, > are very identical on all cores. The memory footprint is twice higher in > the OMPI case (1.5GB/core) than in the MPT case (0.7GB/core). > > What could be wrong with all these, please ? > > I provided (in attachment) the 'ompi_info -all ' output. > The config.log is in attachment as well. > I compiled OMPI with icc. I checked numa and affinity are OK. > > I use the following command to run my OMPI app: > "mpiexec -mca btl_openib_rdma_pipeline_send_length 65536\ > -mca btl_openib_rdma_pipeline_frag_size 65536\ > -mca btl_openib_min_rdma_pipeline_size 65536\ > -mca btl_self_rdma_pipeline_send_length 262144\ > -mca btl_self_rdma_pipeline_frag_size 262144\ > -mca plm_rsh_num_concurrent 4096 -mca mpi_paffinity_alone 1\ > -mca mpi_leave_pinned 1 -mca btl_sm_max_send_size 128\ > -mca coll_tuned_pre_allocate_memory_comm_size_limit 128\ > -mca btl_openib_cq_size 128 -mca btl_ofud_rd_num 128\ > -mca mpool_rdma_rcache_size_limit 131072 -mca mpi_preconnect_mpi 0\ > -mca mpool_sm_min_size 131072 -mca mpi_abort_print_stack 1\ > -mca btl sm,openib,self -mca btl_openib_want_fork_support 0\ > -mca opal_set_max_sys_limits 1 -mca osc_pt2pt_no_locks 1\ > -mca osc_rdma_no_locks 1\ > $PBS_JOBDIR/phmc_tm_p2.$PBS_JOBID -v -f $Jinput". > > OpenIB info: > > 1) OFED-1.4.1, installed by SGI SGI > > 2) Linux xxxxxx 2.6.16.60-0.42.10-smp #1 SMP Tue Apr 27 05:11:27 UTC 2010 > x86_64 x86_64 x86_64 GNU/Linux > OS : SGI ProPack 6SP5 for Linux, Build 605r1.sles10-0909302200 > > 3) Running most probably an SGI subnet manager > > 4) > ibv_devinfo (on a worker node) > hca_id: mlx4_0 > fw_ver: 2.7.000 > node_guid: 0030:48ff:ffcc:4c44 > sys_image_guid: 0030:48ff:ffcc:4c47 > vendor_id: 0x02c9 > vendor_part_id: 26418 > hw_ver: 0xA0 > board_id: SM_2071000001000 > phys_port_cnt: 2 > port: 1 > state: PORT_ACTIVE (4) > max_mtu: 2048 (4) > active_mtu: 2048 (4) > sm_lid: 1 > port_lid: 6009 > port_lmc: 0x00 > > port: 2 > state: PORT_ACTIVE (4) > max_mtu: 2048 (4) > active_mtu: 2048 (4) > sm_lid: 1 > port_lid: 6010 > port_lmc: 0x00 > > 5) > ifconfig -a (on a worker node) > eth0 Link encap:Ethernet HWaddr 00:30:48:CE:73:30 > inet adr:192.168.159.10 Bcast:192.168.159.255 Masque:255.255.255.0 > adr inet6: fe80::230:48ff:fece:7330/64 Scope:Lien > UP BROADCAST NOTRAILERS RUNNING MULTICAST MTU:1500 Metric:1 > RX packets:32337499 errors:0 dropped:0 overruns:0 frame:0 > TX packets:34733462 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 lg file transmission:1000 > RX bytes:11486224753 (10954.1 Mb) TX bytes:16450996864 (15688.8 Mb) > Mémoire:fbc60000-fbc80000 > > eth1 Link encap:Ethernet HWaddr 00:30:48:CE:73:31 > BROADCAST MULTICAST MTU:1500 Metric:1 > RX packets:0 errors:0 dropped:0 overruns:0 frame:0 > TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 lg file transmission:1000 > RX bytes:0 (0.0 b) TX bytes:0 (0.0 b) > Mémoire:fbce0000-fbd00000 > > ib0 Link encap:UNSPEC HWaddr > 80-00-00-48-FE-C0-00-00-00-00-00-00-00-00-00-00 > inet adr:10.148.9.198 Bcast:10.148.255.255 Masque:255.255.0.0 > adr inet6: fe80::230:48ff:ffcc:4c45/64 Scope:Lien > UP BROADCAST RUNNING MULTICAST MTU:65520 Metric:1 > RX packets:115055101 errors:0 dropped:0 overruns:0 frame:0 > TX packets:5390843 errors:0 dropped:182 overruns:0 carrier:0 > collisions:0 lg file transmission:256 > RX bytes:49592870352 (47295.4 Mb) TX bytes:43566897620 (41548.6 Mb) > > ib1 Link encap:UNSPEC HWaddr > 80-00-00-49-FE-C0-00-00-00-00-00-00-00-00-00-00 > inet adr:10.149.9.198 Bcast:10.149.255.255 Masque:255.255.0.0 > adr inet6: fe80::230:48ff:ffcc:4c46/64 Scope:Lien > UP BROADCAST RUNNING MULTICAST MTU:65520 Metric:1 > RX packets:673448 errors:0 dropped:0 overruns:0 frame:0 > TX packets:187 errors:0 dropped:5 overruns:0 carrier:0 > collisions:0 lg file transmission:256 > RX bytes:37713088 (35.9 Mb) TX bytes:11228 (10.9 Kb) > > lo Link encap:Boucle locale > inet adr:127.0.0.1 Masque:255.0.0.0 > adr inet6: ::1/128 Scope:Hôte > UP LOOPBACK RUNNING MTU:16436 Metric:1 > RX packets:33504149 errors:0 dropped:0 overruns:0 frame:0 > TX packets:33504149 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 lg file transmission:0 > RX bytes:5100850397 (4864.5 Mb) TX bytes:5100850397 (4864.5 Mb) > > sit0 Link encap:IPv6-dans-IPv4 > NOARP MTU:1480 Metric:1 > RX packets:0 errors:0 dropped:0 overruns:0 frame:0 > TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 lg file transmission:0 > RX bytes:0 (0.0 b) TX bytes:0 (0.0 b) > > 6) > limit (on a worker node) > cputime unlimited > filesize unlimited > datasize unlimited > stacksize 300000 kbytes > coredumpsize 0 kbytes > memoryuse unlimited > vmemoryuse unlimited > descriptors 16384 > memorylocked unlimited > maxproc 303104 > > If some info is still missing despite all my efforts, please ask. > > Thanks in advance for any hints, Best, G. > > > <config.log.gz><ompi_info-all.001.gz>_______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users
