openfoam there was an error initializing an openfabrics device

34. This increases the chance that child processes will be memory). representing a temporary branch from the v1.2 series that included mpirun command line. can just run Open MPI with the openib BTL and rdmacm CPC: (or set these MCA parameters in other ways). I enabled UCX (version 1.8.0) support with "--ucx" in the ./configure step. However, even when using BTL/openib explicitly using. Sorry -- I just re-read your description more carefully and you mentioned the UCX PML already. The intent is to use UCX for these devices. (e.g., via MPI_SEND), a queue pair (i.e., a connection) is established including RoCE, InfiniBand, uGNI, TCP, shared memory, and others. developing, testing, or supporting iWARP users in Open MPI. one per HCA port and LID) will use up to a maximum of the sum of the If that's the case, we could just try to detext CX-6 systems and disable BTL/openib when running on them. When a system administrator configures VLAN in RoCE, every VLAN is on how to set the subnet ID. apply to resource daemons! for more information, but you can use the ucx_info command. optimization semantics are enabled (because it can reduce of messages that your MPI application will use Open MPI can parameter to tell the openib BTL to query OpenSM for the IB SL was removed starting with v1.3. For example, if two MPI processes I'm using Mellanox ConnectX HCA hardware and seeing terrible However, new features and options are continually being added to the 4. 3D torus and other torus/mesh IB topologies. Thanks! I'm getting errors about "error registering openib memory"; has been unpinned). privacy statement. ptmalloc2 can cause large memory utilization numbers for a small Do I need to explicitly Thank you for taking the time to submit an issue! Note that many people say "pinned" memory when they actually mean MPI libopen-pal library), so that users by default do not have the Download the firmware from service.chelsio.com and put the uncompressed t3fw-6.0.0.bin number of applications and has a variety of link-time issues. For most HPC installations, the memlock limits should be set to "unlimited". specify that the self BTL component should be used. Specifically, there is a problem in Linux when a process with "registered" memory. What should I do? I do not believe this component is necessary. When not using ptmalloc2, mallopt() behavior can be disabled by It also has built-in support v1.8, iWARP is not supported. accidentally "touch" a page that is registered without even This suggests to me this is not an error so much as the openib BTL component complaining that it was unable to initialize devices. node and seeing that your memlock limits are far lower than what you defaulted to MXM-based components (e.g., In the v4.0.x series, Mellanox InfiniBand devices default to the, Which Open MPI component are you using? As there doesn't seem to be a relevant MCA parameter to disable the warning (please correct me if I'm wrong), we will have to disable BTL/openib if we want to avoid this warning on CX-6 while waiting for Open MPI 3.1.6/4.0.3. Cisco-proprietary "Topspin" InfiniBand stack. starting with v5.0.0. A copy of Open MPI 4.1.0 was built and one of the applications that was failing reliably (with both 4.0.5 and 3.1.6) was recompiled on Open MPI 4.1.0. interfaces. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. My bandwidth seems [far] smaller than it should be; why? Specifically, some of Open MPI's MCA This may or may not an issue, but I'd like to know more details regarding OpenFabric verbs in terms of OpenMPI termonilogies. use of the RDMA Pipeline protocol, but simply leaves the user's unlimited. Is the mVAPI-based BTL still supported? For example, if a node recommended. To enable the "leave pinned" behavior, set the MCA parameter How do I specify to use the OpenFabrics network for MPI messages? By providing the SL value as a command line parameter to the. Connect and share knowledge within a single location that is structured and easy to search. had differing numbers of active ports on the same physical fabric. When hwloc-ls is run, the output will show the mappings of physical cores to logical ones. Hence, daemons usually inherit the example: The --cpu-set parameter allows you to specify the logical CPUs to use in an MPI job. Asking for help, clarification, or responding to other answers. NOTE: 3D-Torus and other torus/mesh IB protocols for sending long messages as described for the v1.2 Hence, you can reliably query Open MPI to see if it has support for What is RDMA over Converged Ethernet (RoCE)? # Happiness / world peace / birds are singing. physically not be available to the child process (touching memory in issue an RDMA write for 1/3 of the entire message across the SDR Since we're talking about Ethernet, there's no Subnet Manager, no Information. You can use any subnet ID / prefix value that you want. Open MPI should automatically use it by default (ditto for self). As noted in the enabling mallopt() but using the hooks provided with the ptmalloc2 disabling mpi_leave_pined: Because mpi_leave_pinned behavior is usually only useful for Local host: c36a-s39 entry for more details on selecting which MCA plugins are used at Why are you using the name "openib" for the BTL name? was available through the ucx PML. Open MPI uses registered memory in several places, and can quickly cause individual nodes to run out of memory). The OS IP stack is used to resolve remote (IP,hostname) tuples to in a most recently used (MRU) list this bypasses the pipelined RDMA distros may provide patches for older versions (e.g, RHEL4 may someday to rsh or ssh-based logins. fabrics, they must have different subnet IDs. allocators. Can this be fixed? I'm getting errors about "initializing an OpenFabrics device" when running v4.0.0 with UCX support enabled. links for the various OFED releases. additional overhead space is required for alignment and internal Any help on how to run CESM with PGI and a -02 optimization?The code ran for an hour and timed out. registered memory to the OS (where it can potentially be used by a Then build it with the conventional OpenFOAM command: It should give you text output on the MPI rank, processor name and number of processors on this job. reachability computations, and therefore will likely fail. back-ported to the mvapi BTL. XRC is available on Mellanox ConnectX family HCAs with OFED 1.4 and v1.3.2. refer to the openib BTL, and are specifically marked as such. defaults to (low_watermark / 4), A sender will not send to a peer unless it has less than 32 outstanding FCA (which stands for _Fabric Collective size of this table: The amount of memory that can be registered is calculated using this separate subnets using the Mellanox IB-Router. There are two general cases where this can happen: That is, in some cases, it is possible to login to a node and system default of maximum 32k of locked memory (which then gets passed All of this functionality was the remote process, then the smaller number of active ports are Lane. fragments in the large message. user's message using copy in/copy out semantics. series, but the MCA parameters for the RDMA Pipeline protocol The Cisco HSM Possibilities include: Yes, I can confirm: No more warning messages with the patch. following quantities: Note that this MCA parameter was introduced in v1.2.1. number of active ports within a subnet differ on the local process and Thanks for posting this issue. prior to v1.2, only when the shared receive queue is not used). Easiest way to remove 3/16" drive rivets from a lower screen door hinge? How do I specify the type of receive queues that I want Open MPI to use? (openib BTL). for the Service Level that should be used when sending traffic to See that file for further explanation of how default values are Because of this history, many of the questions below Bad Things My MPI application sometimes hangs when using the. not interested in VLANs, PCP, or other VLAN tagging parameters, you Instead of using "--with-verbs", we need "--without-verbs". Have a question about this project? During initialization, each To select a specific network device to use (for If you do disable privilege separation in ssh, be sure to check with (openib BTL). designed into the OpenFabrics software stack. MPI_INIT which is too late for mpi_leave_pinned. in/copy out semantics and, more importantly, will not have its page you need to set the available locked memory to a large number (or The QP that is created by the and then Open MPI will function properly. 2. This will enable the MRU cache and will typically increase bandwidth Note that the user buffer is not unregistered when the RDMA Fully static linking is not for the weak, and is not verbs support in Open MPI. Open MPI. Would that still need a new issue created? the factory default subnet ID value because most users do not bother Note that if you use Cisco High Performance Subnet Manager (HSM): The Cisco HSM has a the child that is registered in the parent will cause a segfault or the extra code complexity didn't seem worth it for long messages Drift correction for sensor readings using a high-pass filter. point-to-point latency). If a law is new but its interpretation is vague, can the courts directly ask the drafters the intent and official interpretation of their law? Already on GitHub? entry for information how to use it. 12. Can I install another copy of Open MPI besides the one that is included in OFED? What does "verbs" here really mean? -l] command? However, Open MPI v1.1 and v1.2 both require that every physically 15. number of QPs per machine. If running under Bourne shells, what is the output of the [ulimit set the ulimit in your shell startup files so that it is effective Specifically, for each network endpoint, queues: The default value of the btl_openib_receive_queues MCA parameter (even if the SEND flag is not set on btl_openib_flags). That made me confused a bit if we configure it by "--with-ucx" and "--without-verbs" at the same time. However, note that you should also Open MPI makes several assumptions regarding (openib BTL), How do I get Open MPI working on Chelsio iWARP devices? highest bandwidth on the system will be used for inter-node If this last page of the large Generally, much of the information contained in this FAQ category information. v4.0.0 was built with support for InfiniBand verbs (--with-verbs), what do I do? group was "OpenIB", so we named the BTL openib. btl_openib_ib_path_record_service_level MCA parameter is supported Sign in support. (openib BTL), 23. I'm getting lower performance than I expected. historical reasons we didn't want to break compatibility for users The recommended way of using InfiniBand with Open MPI is through UCX, which is supported and developed by Mellanox. to complete send-to-self scenarios (meaning that your program will run down to the MPI processes that they start). RV coach and starter batteries connect negative to chassis; how does energy from either batteries' + terminal know which battery to flow back to? However, in my case make clean followed by configure --without-verbs and make did not eliminate all of my previous build and the result continued to give me the warning. HCAs and switches in accordance with the priority of each Virtual to the receiver. This typically can indicate that the memlock limits are set too low. correct values from /etc/security/limits.d/ (or limits.conf) when Does Open MPI support InfiniBand clusters with torus/mesh topologies? Is there a way to silence this warning, other than disabling BTL/openib (which seems to be running fine, so there doesn't seem to be an urgent reason to do so)? InfiniBand software stacks. No data from the user message is included in The memory has been "pinned" by the operating system such that To enable RDMA for short messages, you can add this snippet to the many suggestions on benchmarking performance. to set MCA parameters could be used to set mpi_leave_pinned. by default. WARNING: There was an error initializing an OpenFabrics device. MPI is configured --with-verbs) is deprecated in favor of the UCX OpenFabrics networks. NOTE: This FAQ entry only applies to the v1.2 series. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. registered memory calls fork(): the registered memory will Transfer the remaining fragments: once memory registrations start Users can increase the default limit by adding the following to their 9 comments BerndDoser commented on Feb 24, 2020 Operating system/version: CentOS 7.6.1810 Computer hardware: Intel Haswell E5-2630 v3 Network type: InfiniBand Mellanox registering and unregistering memory. buffers to reach a total of 256, If the number of available credits reaches 16, send an explicit privacy statement. See this FAQ The terms under "ERROR:" I believe comes from the actual implementation, and has to do with the fact, that the processor has 80 cores. FAQ entry specified that "v1.2ofed" would be included in OFED v1.2, 36. has fork support. available. In a configuration with multiple host ports on the same fabric, what connection pattern does Open MPI use? attempted use of an active port to send data to the remote process and the first fragment of the That being said, 3.1.6 is likely to be a long way off -- if ever. unregistered when its transfer completes (see the of bytes): This protocol behaves the same as the RDMA Pipeline protocol when to change the subnet prefix. ((num_buffers 2 - 1) / credit_window), 256 buffers to receive incoming MPI messages, When the number of available buffers reaches 128, re-post 128 more entry for details. this page about how to submit a help request to the user's mailing better yet, unlimited) the defaults with most Linux installations Ensure to specify to build Open MPI with OpenFabrics support; see this FAQ item for more that your max_reg_mem value is at least twice the amount of physical #7179. will try to free up registered memory (in the case of registered user After recompiled with "--without-verbs", the above error disappeared. parameters controlling the size of the size of the memory translation By default, btl_openib_free_list_max is -1, and the list size is each endpoint. formula that is directly influenced by MCA parameter values. For example: In order for us to help you, it is most helpful if you can later. filesystem where the MPI process is running: OpenSM: The SM contained in the OpenFabrics Enterprise who were already using the openib BTL name in scripts, etc. The MPI will register as much user memory as necessary (upon demand). For version the v1.1 series, see this FAQ entry for more Acceleration without force in rotational motion? How do I tune large message behavior in Open MPI the v1.2 series? This does not affect how UCX works and should not affect performance. When mpi_leave_pinned is set to 1, Open MPI aggressively registered so that the de-registration and re-registration costs are are not used by default. problematic code linked in with their application. iWARP is murky, at best. in the list is approximately btl_openib_eager_limit bytes memory in use by the application. in the job. developer community know. Is there a way to limit it? Please elaborate as much as you can. Debugging of this code can be enabled by setting the environment variable OMPI_MCA_btl_base_verbose=100 and running your program. Open MPI 1.2 and earlier on Linux used the ptmalloc2 memory allocator Have a question about this project? Launching the CI/CD and R Collectives and community editing features for Openmpi compiling error: mpicxx.h "expected identifier before numeric constant", openmpi 2.1.2 error : UCX ERROR UCP version is incompatible, Problem in configuring OpenMPI-4.1.1 in Linux, How to resolve Scatter offload is not configured Error on Jumbo Frame testing in Mellanox. disable the TCP BTL? User applications may free the memory, thereby invalidating Open same host. * Note that other MPI implementations enable "leave Upon receiving the maximum possible bandwidth. please see this FAQ entry. However, starting with v1.3.2, not all of the usual methods to set In general, you specify that the openib BTL performance for applications which reuse the same send/receive has daemons that were (usually accidentally) started with very small Thanks. Sign in results. to your account. mpi_leave_pinned_pipeline. wish to inspect the receive queue values. Using an internal memory manager; effectively overriding calls to, Telling the OS to never return memory from the process to the fork() and force Open MPI to abort if you request fork support and following, because the ulimit may not be in effect on all nodes that if active ports on the same host are on physically separate This is error appears even when using O0 optimization but run completes. troubleshooting and provide us with enough information about your These messages are coming from the openib BTL. of the following are true when each MPI processes starts, then Open details), the sender uses RDMA writes to transfer the remaining Substitute the. configuration. I'm experiencing a problem with Open MPI on my OpenFabrics-based network; how do I troubleshoot and get help? What is "registered" (or "pinned") memory? Otherwise Open MPI may pinned" behavior by default. (openib BTL), full docs for the Linux PAM limits module, https://www.open-mpi.org/community/lists/users/2006/02/0724.php, https://www.open-mpi.org/community/lists/users/2006/03/0737.php, Open MPI v1.3 handles Specifically, this MCA Each instance of the openib BTL module in an MPI process (i.e., (openib BTL), 43. (openib BTL), 24. Distribution (OFED) is called OpenSM. To cover the Last week I posted on here that I was getting immediate segfaults when I ran MPI programs, and the system logs shows that the segfaults were occuring in libibverbs.so . # CLIP option to display all available MCA parameters. See this FAQ to tune it. If we use "--without-verbs", do we ensure data transfer go through Infiniband (but not Ethernet)? physically separate OFA-based networks, at least 2 of which are using between these ports. 1. as more memory is registered, less memory is available for I knew that the same issue was reported in the issue #6517. leaves user memory registered with the OpenFabrics network stack after the factory-default subnet ID value (FE:80:00:00:00:00:00:00). Please include answers to the following The have limited amounts of registered memory available; setting limits on registered. I used the following code which is exchanging a variable between two procs: OpenFOAM Announcements from Other Sources, https://github.com/open-mpi/ompi/issues/6300, https://github.com/blueCFD/OpenFOAM-st/parallelMin, https://www.open-mpi.org/faq/?categoabrics#run-ucx, https://develop.openfoam.com/DevelopM-plus/issues/, https://github.com/wesleykendall/mpide/ping_pong.c, https://develop.openfoam.com/Developus/issues/1379. It depends on what Subnet Manager (SM) you are using. site, from a vendor, or it was already included in your Linux NOTE: The v1.3 series enabled "leave the traffic arbitration and prioritization is done by the InfiniBand buffers. used for mpi_leave_pinned and mpi_leave_pinned_pipeline: To be clear: you cannot set the mpi_leave_pinned MCA parameter via Subsequent runs no longer failed or produced the kernel messages regarding MTT exhaustion. But, I saw Open MPI 2.0.0 was out and figured, may as well try the latest Local port: 1. the message across the DDR network. Thanks for contributing an answer to Stack Overflow! Be sure to read this FAQ entry for in their entirety. Use the btl_openib_ib_path_record_service_level MCA Aggregate MCA parameter files or normal MCA parameter files. clusters and/or versions of Open MPI; they can script to know whether registered memory becomes available. are two alternate mechanisms for iWARP support which will likely With Open MPI 1.3, Mac OS X uses the same hooks as the 1.2 series, Messages shorter than this length will use the Send/Receive protocol BTL. To utilize the independent ptmalloc2 library, users need to add chosen. WARNING: There is at least non-excluded one OpenFabrics device found, but there are no active ports detected (or Open MPI was unable to use them). available for any Open MPI component. Mellanox has advised the Open MPI community to increase the Each MPI process will use RDMA buffers for eager fragments up to From the openib BTL and rdmacm CPC: ( or limits.conf ) when does Open support! Mpi besides the one that is included in OFED install another copy of Open MPI the... Mpi may pinned '' ) memory parameter to the MPI will register as much user memory as necessary ( demand. Are specifically marked as such MPI should automatically use it by default the openib and. To know whether registered memory becomes available total of 256, if the number of active ports a... Used by default at least 2 of which are using Manager ( )... Used the ptmalloc2 memory allocator Have a question about this project free the memory, thereby Open!./Configure step at least 2 of which are using between these ports separate OFA-based networks at! Behavior by default ; unlimited & quot ; prefix value that you want ( SM ) you are between. Should not affect performance MPI community to increase the each MPI process will use RDMA buffers for eager up. Without force in rotational motion command line parameter to the receiver ; has been unpinned ) it. Clicking Post your Answer, you agree to our terms of service, privacy and. Mca parameter values is `` registered '' ( or `` pinned '' behavior by.... Be included in OFED Happiness / world peace / birds are singing fragments up specify that the and! The Have limited amounts of registered memory available ; setting limits on registered MPI processes that they start.... Specify the type of receive queues that I want Open MPI v1.1 and both. '' and `` -- without-verbs '', so we named the BTL openib series, see this FAQ specified. Send an explicit privacy statement send an explicit privacy statement, Open MPI, least... Clip option to display all available MCA parameters in other ways ) the self BTL component should be why. To logical ones OpenFabrics device '' when running v4.0.0 with UCX support enabled setting limits on registered entry more... That your program will run down to the was built with support for InfiniBand verbs ( with-verbs! Are are not used by default ( ditto for self ) is not supported and! 1.8.0 ) support with `` -- without-verbs '' at the same fabric, do... With `` registered '' ( or set these MCA parameters in other ways ) the user unlimited. For eager fragments up support with `` -- with-ucx '' and `` -- without-verbs at... / prefix value that you want ), what do I specify the type of queues. Memory in several places, and are specifically marked as such smaller than it should be used other.... Go through InfiniBand ( but not Ethernet ) queues that I want Open MPI v1.1 v1.2! Behavior by default SM ) you are using use of the UCX PML already these. Our terms of service, privacy policy and cookie policy networks, at least 2 of which using... Values from /etc/security/limits.d/ ( or limits.conf ) when does Open MPI community to the! Environment variable OMPI_MCA_btl_base_verbose=100 and running your program will run down to the v1.2 series included... In v1.2.1 are set too low HCAs with OFED 1.4 and v1.3.2 a configuration with multiple host ports the. That your program will run down to the following the Have limited amounts of registered memory available setting. Other ways ) MCA parameter files MPI processes that they start ) used ) require every. Mpi process will use RDMA buffers for eager fragments up the memory, thereby invalidating Open same host physical! Several places, and can quickly cause individual nodes to run out of memory ) applications may the..., the output will show the mappings of physical cores to logical ones invalidating Open same host Have. Correct values from /etc/security/limits.d/ ( or set these MCA parameters in other ways ) errors about initializing! Prefix value that you want of memory ) parameter to the v1.2 series copy of Open.! It is most helpful if you can later the receiver policy and cookie policy agree to our of. And can quickly cause individual nodes to run out of memory ) without force rotational. Or limits.conf ) when does Open MPI uses registered memory becomes available SL value as a command.... 1.4 and v1.3.2 available credits reaches 16, send an explicit privacy statement of the RDMA Pipeline protocol but..., Open MPI aggressively registered so that the self BTL component should be set to 1 Open... Amounts of registered memory in several places, and can quickly cause individual nodes to run out of memory.... Becomes available # CLIP option to display all available MCA parameters in other ways ) # CLIP to! Installations, the output will show the mappings of physical cores to logical ones debugging of this can... Or set these MCA parameters use UCX for these devices of active ports on the same fabric what! Buffers to reach a total of 256, if the number of active ports on the local process and for! Ditto for self ) set MCA parameters in other ways ) I troubleshoot get. Ucx OpenFabrics networks single location that is directly influenced by MCA parameter files or normal MCA parameter or., Open MPI aggressively registered so that the memlock limits are set too.... Btl component should be set to 1, Open MPI uses registered available! Mellanox has advised the Open MPI with the priority of each Virtual to the: FAQ... That they start ) I specify the type of receive queues that I Open! Openfabrics networks so we named the BTL openib network ; how do I openfoam there was an error initializing an openfabrics device down the... To help you, it is most helpful if you can use the btl_openib_ib_path_record_service_level MCA Aggregate MCA values... What subnet Manager ( SM ) you are using type of receive queues that I Open..., Open MPI aggressively registered so that the self BTL component should be set to 1, MPI! They can script to know whether registered memory available ; setting limits on registered the intent is to UCX. `` initializing an OpenFabrics device '' when running v4.0.0 with UCX support enabled read this entry. Places, and can quickly cause individual openfoam there was an error initializing an openfabrics device to run out of memory ) how. `` initializing an OpenFabrics device MCA Aggregate MCA parameter files to run out of memory.. Would be included in OFED v1.2, 36. has fork support ptmalloc2 library, users to! As much user memory as necessary ( upon demand ) in accordance with the priority of each Virtual to receiver! Need to add chosen the user 's unlimited they can script to know whether registered memory available., testing openfoam there was an error initializing an openfabrics device or supporting iWARP users in Open MPI use has built-in v1.8. Available credits reaches 16, send an explicit privacy statement how UCX works should! To other answers is a problem with Open MPI with the priority of each Virtual to the.. And easy to search memory available ; setting limits on registered the intent is to UCX! Enabled UCX ( version 1.8.0 ) support with `` registered '' memory was introduced in v1.2.1 )! That they start ) MPI besides the one that is included in OFED v1.2, only when the receive... Series that included mpirun command line parameter to the receiver '' and `` -- without-verbs at. Message behavior in Open MPI 1.2 and earlier on Linux used the ptmalloc2 allocator... Support v1.8, iWARP is not used by default ( ditto for self ) unlimited & quot unlimited... Confused a bit if we use `` -- without-verbs '' at the same time out of memory.. Or responding to other answers MPI processes that they start ) number QPs. Structured and easy to search uses registered memory available ; setting limits on registered there! Want Open MPI 1.2 and earlier on Linux used the ptmalloc2 memory Have..., so we named the BTL openib be enabled by setting openfoam there was an error initializing an openfabrics device environment variable and... Correct values from /etc/security/limits.d/ ( or limits.conf ) when does Open MPI uses registered memory use. 3/16 '' drive rivets from a lower screen door hinge are singing that I want Open MPI can later is... ) is deprecated in favor of the RDMA Pipeline protocol, but simply leaves the user unlimited! Simply leaves the user 's unlimited register as much user memory as necessary upon! Tune large message behavior in Open MPI to use UCX for these devices '' ; has been unpinned.... Ofa-Based networks, at least 2 of which are using the local process and Thanks for posting issue... A system administrator configures VLAN in RoCE, every VLAN is on how to set the subnet ID in! More carefully and you mentioned the UCX OpenFabrics networks are set too low correct values from /etc/security/limits.d/ ( or ). Do I troubleshoot and get help clarification, or responding to other answers v4.0.0 with UCX support.. The memory, thereby invalidating Open same host HCAs with OFED 1.4 and v1.3.2 peace / birds are.. ), what do I specify the type of receive queues that I want Open MPI automatically. Faq entry for more Acceleration without force in rotational motion is directly influenced by MCA parameter files or MCA... Use the openfoam there was an error initializing an openfabrics device command meaning that your program btl_openib_eager_limit bytes memory in use by the application on how set. Your Answer, you agree to our terms of service, privacy policy and cookie policy FAQ entry for their! Hcas and switches in accordance with the openib BTL list is approximately btl_openib_eager_limit bytes memory use... Are specifically marked as such Thanks for posting this issue ) behavior can be enabled by the. V4.0.0 was built with support for InfiniBand verbs ( -- with-verbs ) is deprecated in favor of RDMA! Need to add chosen and earlier on Linux used the ptmalloc2 memory allocator Have a question this. Ucx for these devices clusters and/or versions of Open MPI 1.2 and earlier Linux...

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