Open MPI main development repository (BSD license)
https://github.com/open-mpi/ompi
09f98cb165
* Resolve set-but-not-used issues * Resolve incorrect const notation (I checked with George first to see what const notation he actually wanted) * Comment out unused code (didn't delete it because it's useful debugging code) * Resolve int<-->void* casting * Resolved signed / unsigned comparisons This commit was SVN r30225. |
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configure.ac | ||
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VERSION |
Copyright (c) 2004-2007 The Trustees of Indiana University and Indiana University Research and Technology Corporation. All rights reserved. Copyright (c) 2004-2007 The University of Tennessee and The University of Tennessee Research Foundation. All rights reserved. Copyright (c) 2004-2008 High Performance Computing Center Stuttgart, University of Stuttgart. All rights reserved. Copyright (c) 2004-2007 The Regents of the University of California. All rights reserved. Copyright (c) 2006-2012 Cisco Systems, Inc. All rights reserved. Copyright (c) 2006-2011 Mellanox Technologies. All rights reserved. Copyright (c) 2006-2012 Oracle and/or its affiliates. All rights reserved. Copyright (c) 2007 Myricom, Inc. All rights reserved. Copyright (c) 2008 IBM Corporation. All rights reserved. Copyright (c) 2010 Oak Ridge National Labs. All rights reserved. Copyright (c) 2011 University of Houston. All rights reserved. Copyright (c) 2013 Intel, Inc. All rights reserved $COPYRIGHT$ Additional copyrights may follow $HEADER$ =========================================================================== When submitting questions and problems, be sure to include as much extra information as possible. This web page details all the information that we request in order to provide assistance: http://www.open-mpi.org/community/help/ The best way to report bugs, send comments, or ask questions is to sign up on the user's and/or developer's mailing list (for user-level and developer-level questions; when in doubt, send to the user's list): users@open-mpi.org devel@open-mpi.org Because of spam, only subscribers are allowed to post to these lists (ensure that you subscribe with and post from exactly the same e-mail address -- joe@example.com is considered different than joe@mycomputer.example.com!). Visit these pages to subscribe to the lists: http://www.open-mpi.org/mailman/listinfo.cgi/users http://www.open-mpi.org/mailman/listinfo.cgi/devel Thanks for your time. =========================================================================== Much, much more information is also available in the Open MPI FAQ: http://www.open-mpi.org/faq/ =========================================================================== The following abbreviated list of release notes applies to this code base as of this writing (22 February 2012): General notes ------------- - Open MPI now includes two public software layers: MPI and OpenSHMEM. Throughout this document, references to Open MPI implicitly include both of these layers. When distinction between these two layers is necessary, we will reference them as the "MPI" and "OSHMEM" layers respectively. OpenSHMEM is a collaborative effort between academia, industry, and the U.S. Government to create a specification for a standardized API for parallel programming in the Partitioned Global Address Space (PGAS.) For more information about the OpenSHMEM project, including access to the current OpenSHMEM specification, please visit: http://openshmem.org/ The OpenSHMEM implementation contained herein is provided by Mellanox Technologies Inc. made possible by the support and patient guidance of the Open MPI community. This implementation attempts to be portable, to allow it to be deployed in multiple environments, and to be a starting point for optimizations targeted to particular hardware platforms. However, until other network vendors and/or institutions contribute platform specific optimizations, this implementation will most likely provide optimal performance on Mellanox hardware and software stacks. - Open MPI includes support for a wide variety of supplemental hardware and software package. When configuring Open MPI, you may need to supply additional flags to the "configure" script in order to tell Open MPI where the header files, libraries, and any other required files are located. As such, running "configure" by itself may not include support for all the devices (etc.) that you expect, especially if their support headers / libraries are installed in non-standard locations. Network interconnects are an easy example to discuss -- Myrinet and OpenFabrics networks, for example, both have supplemental headers and libraries that must be found before Open MPI can build support for them. You must specify where these files are with the appropriate options to configure. See the listing of configure command-line switches, below, for more details. - The majority of Open MPI's documentation is here in this file, the included man pages, and on the web site FAQ (http://www.open-mpi.org/). This will eventually be supplemented with cohesive installation and user documentation files. - Note that Open MPI documentation uses the word "component" frequently; the word "plugin" is probably more familiar to most users. As such, end users can probably completely substitute the word "plugin" wherever you see "component" in our documentation. For what it's worth, we use the word "component" for historical reasons, mainly because it is part of our acronyms and internal API function calls. - The run-time systems that are currently supported are: - rsh / ssh - LoadLeveler - PBS Pro, Torque - Platform LSF (v7.0.2 and later) - SLURM - Cray XT-3, XT-4, and XT-5 - Oracle Grid Engine (OGE) 6.1, 6.2 and open source Grid Engine - Systems that have been tested are: - Linux (various flavors/distros), 32 bit, with gcc - Linux (various flavors/distros), 64 bit (x86), with gcc, Absoft, Intel, and Portland (*) - OS X (10.5, 10.6, 10.7, 10.8, 10.9), 32 and 64 bit (x86_64), with gcc and Absoft compilers (*) (*) Be sure to read the Compiler Notes, below. - Other systems have been lightly (but not fully tested): - Cygwin 32 & 64 bit with gcc - ARMv4, ARMv5, ARMv6, ARMv7 (when using non-inline assembly; only ARMv7 is fully supported when -DOMPI_DISABLE_INLINE_ASM is used). - Other 64 bit platforms (e.g., Linux on PPC64) - Oracle Solaris 10 and 11, 32 and 64 bit (SPARC, i386, x86_64), with Oracle Solaris Studio 12.2 and 12.3 Compiler Notes -------------- - Mixing compilers from different vendors when building Open MPI (e.g., using the C/C++ compiler from one vendor and the Fortran compiler from a different vendor) has been successfully employed by some Open MPI users (discussed on the Open MPI user's mailing list), but such configurations are not tested and not documented. For example, such configurations may require additional compiler / linker flags to make Open MPI build properly. - In general, the latest versions of compilers of a given vendor's series have the least bugs. We have seen cases where Vendor XYZ's compiler version A.B fails to compile Open MPI, but version A.C (where C>B) works just fine. If you run into a compile failure, you might want to double check that you have the latest bug fixes and patches for your compiler. - Absoft 11.5.2 plus a service pack from September 2012 (which Absoft says is available upon request), or a version later than 11.5.2 (e.g., 11.5.3), is required to compile the new Fortran mpi_f08 module. - Open MPI does not support the Sparc v8 CPU target. However, as of Solaris Studio 12.1, and later compilers, one should not specify -xarch=v8plus or -xarch=v9. The use of the options -m32 and -m64 for producing 32 and 64 bit targets, respectively, are now preferred by the Solaris Studio compilers. - It has been noticed that if one uses CXX=sunCC, in which sunCC is a link in the Solaris Studio compiler release, that the OMPI build system has issue with sunCC and does not build libmpi_cxx.so. Therefore the make install fails. So we suggest that one should use CXX=CC, which works, instead of CXX=sunCC. - If one tries to build OMPI on Ubuntu with Solaris Studio using the C++ compiler and the -m32 option, you might see a warning: CC: Warning: failed to detect system linker version, falling back to custom linker usage And the build will fail. One can overcome this error by either setting LD_LIBRARY_PATH to the location of the 32 bit libraries (most likely /lib32), or giving LDFLAGS="-L/lib32 -R/lib32" to the configure command. Officially, Solaris Studio is not supported on Ubuntu Linux distributions, so additional problems might be incurred. - The Solaris Studio 12.2 compilers may have a problem compiling VampirTrace on some Linux platforms. You can either upgrade to a later version of the Solaris Studio compilers (e.g., 12.3 does not have this problem), or disable building VampirTrace. - Open MPI does not support the gccfss compiler (GCC For SPARC Systems; a now-defunct compiler project from Sun). - At least some versions of the Intel 8.1 compiler seg fault while compiling certain Open MPI source code files. As such, it is not supported. - The Intel 9.0 v20051201 compiler on IA64 platforms seems to have a problem with optimizing the ptmalloc2 memory manager component (the generated code will segv). As such, the ptmalloc2 component will automatically disable itself if it detects that it is on this platform/compiler combination. The only effect that this should have is that the MCA parameter mpi_leave_pinned will be inoperative. - It has been reported that the Intel 9.1 and 10.0 compilers fail to compile Open MPI on IA64 platforms. As of 12 Sep 2012, there is very little (if any) testing performed on IA64 platforms (with any compiler). Support is "best effort" for these platforms, but it is doubtful that any effort will be expended to fix the Intel 9.1 / 10.0 compiler issuers on this platform. - Early versions of the Intel 12.1 Linux compiler suite on x86_64 seem to have a bug that prevents Open MPI from working. Symptoms including immediate segv of the wrapper compilers (e.g., mpicc) and MPI applications. As of 1 Feb 2012, if you upgrade to the latest version of the Intel 12.1 Linux compiler suite, the problem will go away. - Early versions of the Portland Group 6.0 compiler have problems creating the C++ MPI bindings as a shared library (e.g., v6.0-1). Tests with later versions show that this has been fixed (e.g., v6.0-5). - The Portland Group compilers prior to version 7.0 require the "-Msignextend" compiler flag to extend the sign bit when converting from a shorter to longer integer. This is is different than other compilers (such as GNU). When compiling Open MPI with the Portland compiler suite, the following flags should be passed to Open MPI's configure script: shell$ ./configure CFLAGS=-Msignextend CXXFLAGS=-Msignextend \ --with-wrapper-cflags=-Msignextend \ --with-wrapper-cxxflags=-Msignextend ... This will both compile Open MPI with the proper compile flags and also automatically add "-Msignextend" when the C and C++ MPI wrapper compilers are used to compile user MPI applications. - Using the MPI C++ bindings with older versions of the Pathscale compiler on some platforms is an old issue that seems to be a problem when Pathscale uses a back-end GCC 3.x compiler. Here's a proposed solution from the Pathscale support team (from July 2010): The proposed work-around is to install gcc-4.x on the system and use the pathCC -gnu4 option. Newer versions of the compiler (4.x and beyond) should have this fixed, but we'll have to test to confirm it's actually fixed and working correctly. We don't anticipate that this will be much of a problem for Open MPI users these days (our informal testing shows that not many users are still using GCC 3.x). Contact Pathscale support if you continue to have problems with Open MPI's C++ bindings. - There is currently a known issue with the PGI compilers on OS X Lion. See https://svn.open-mpi.org/trac/ompi/ticket/3011. - Using the Absoft compiler to build the MPI Fortran bindings on Suse 9.3 is known to fail due to a Libtool compatibility issue. - MPI Fortran API support has been completely overhauled since the Open MPI v1.5/v1.6 series. ******************************************************************** ******************************************************************** *** There is now only a single Fortran MPI wrapper compiler and *** a single Fortran OSHMEM wrapper compiler: *** mpifort, and oshfort. mpif77 and mpif90 still exist, but they *** are symbolic links to mpifort. ******************************************************************** *** Similarly, Open MPI's configure script only recognizes the FC *** and FCFLAGS environment variables (to specify the Fortran *** compiler and compiler flags, respectively). The F77 and FFLAGS *** environment variables are IGNORED. ******************************************************************** ******************************************************************** You can use either ompi_info or oshmem_info to see with which Fortran compiler Open MPI was configured and compiled. There are up to three sets of Fortran MPI bindings that may be provided depending on your Fortran compiler): - mpif.h: This is the first MPI Fortran interface that was defined in MPI-1. It is a file that is included in Fortran source code. Open MPI's mpif.h does not declare any MPI subroutines; they are all implicit. - mpi module: The mpi module file was added in MPI-2. It provides strong compile-time parameter type checking for MPI subroutines. - mpi_f08 module: The mpi_f08 module was added in MPI-3. It provides many advantages over the mpif.h file and mpi module. For example, MPI handles have distinct types (vs. all being integers). See the MPI-3 document for more details. *** The mpi_f08 module is STRONGLY is recommended for all new MPI Fortran subroutines and applications. Note that the mpi_f08 module can be used in conjunction with the other two Fortran MPI bindings in the same application (only one binding can be used per subroutine/function, however). Full interoperability between mpif.h/mpi module and mpi_f08 module MPI handle types is provided, allowing mpi_f08 to be used in new subroutines in legacy MPI applications. Per the OSHMEM specification, there is only one Fortran OSHMEM binding provided: - shmem.fh: All Fortran OpenSHMEM programs **should** include 'shmem.fh', and Fortran OSHMEM programs that use constants defined by OpenSHMEM **MUST** include 'shmem.fh'. The following notes apply to the above-listed Fortran bindings: - The mpi_f08 module is new and has been tested with the Intel Fortran compiler. Other modern Fortran compilers may also work (but are, as yet, currently untested). It is expected that this support will mature over time. As of v4.9, the GNU Fortran compiler (gfortran) is *not* supported with the mpi_f08 module (gfortran lacks some necessary modern Fortran features, sorry). - All Fortran compilers support the mpif.h/shmem.fh-based bindings. - If Open MPI is built with a non-gfortran compiler or with gfortran >=v4.9, all MPI subroutines will be prototyped in the mpi module, meaning that all calls to MPI subroutines will have their parameter types checked at compile time. - If Open MPI is built with gfortran <v4.9, it will compile a limited "mpi" module -- not all MPI subroutines will be prototyped due to both poor design of the mpi module in the MPI-2 specification and a lack of features in older versions of gfortran. Specifically, all MPI subroutines with no "choice" buffers are prototyped and will receive strong parameter type checking at run-time (e.g., MPI_INIT, MPI_COMM_RANK, etc.). MPI subroutines with one choice buffer (e.g., MPI_SEND) are prototyped for all intrinsic Fortran types for scalars and ranks 1 through 4 (the --with-gfortran-max-array-dim configure switch can be used to increase the max array rank supported to up to 7). MPI subroutines with two choice buffers (e.g., MPI_GATHER) are *not* prototyped. These subroutines can still be called in MPI applications; they just will not receive strong parameter type checking. General Run-Time Support Notes ------------------------------ - The Open MPI installation must be in your PATH on all nodes (and potentially LD_LIBRARY_PATH (or DYLD_LIBRARY_PATH), if libmpi/libshmem is a shared library), unless using the --prefix or --enable-mpirun-prefix-by-default functionality (see below). - Open MPI's run-time behavior can be customized via MCA ("MPI Component Architecture") parameters (see below for more information on how to get/set MCA parameter values). Some MCA parameters can be set in a way that renders Open MPI inoperable (see notes about MCA parameters later in this file). In particular, some parameters have required options that must be included. - If specified, the "btl" parameter must include the "self" component, or Open MPI will not be able to deliver messages to the same rank as the sender. For example: "mpirun --mca btl tcp,self ..." - If specified, the "btl_tcp_if_exclude" paramater must include the loopback device ("lo" on many Linux platforms), or Open MPI will not be able to route MPI messages using the TCP BTL. For example: "mpirun --mca btl_tcp_if_exclude lo,eth1 ..." - Running on nodes with different endian and/or different datatype sizes within a single parallel job is supported in this release. However, Open MPI does not resize data when datatypes differ in size (for example, sending a 4 byte MPI_DOUBLE and receiving an 8 byte MPI_DOUBLE will fail). MPI Functionality and Features ------------------------------ - All MPI-2.2 and most MPI-3 functionality is supported. - When using MPI deprecated functions, some compilers will emit warnings. For example: shell$ cat deprecated_example.c #include <mpi.h> void foo(void) { MPI_Datatype type; MPI_Type_struct(1, NULL, NULL, NULL, &type); } shell$ mpicc -c deprecated_example.c deprecated_example.c: In function 'foo': deprecated_example.c:4: warning: 'MPI_Type_struct' is deprecated (declared at /opt/openmpi/include/mpi.h:1522) shell$ - MPI_THREAD_MULTIPLE support is included, but is only lightly tested. It likely does not work for thread-intensive applications. Note that *only* the MPI point-to-point communication functions for the BTL's listed here are considered thread safe. Other support functions (e.g., MPI attributes) have not been certified as safe when simultaneously used by multiple threads. - tcp - sm - self Note that Open MPI's thread support is in a fairly early stage; the above devices may *work*, but the latency is likely to be fairly high. Specifically, efforts so far have concentrated on *correctness*, not *performance* (yet). - MPI_REAL16 and MPI_COMPLEX32 are only supported on platforms where a portable C datatype can be found that matches the Fortran type REAL*16, both in size and bit representation. - The "libompitrace" library is bundled in Open MPI and is installed by default (it can be disabled via the --disable-libompitrace flag). This library provides a simplistic tracing of select MPI function calls via the MPI profiling interface. Linking it in to your appliation via (e.g., via -lompitrace) will automatically output to stderr when some MPI functions are invoked: shell$ mpicc hello_world.c -o hello_world -lompitrace shell$ mpirun -np 1 hello_world.c MPI_INIT: argc 1 Hello, world, I am 0 of 1 MPI_BARRIER[0]: comm MPI_COMM_WORLD MPI_FINALIZE[0] shell$ Keep in mind that the output from the trace library is going to stderr, so it may output in a slightly different order than the stdout from your application. This library is being offered as a "proof of concept" / convenience from Open MPI. If there is interest, it is trivially easy to extend it to printf for other MPI functions. Patches and/or suggestions would be greatfully appreciated on the Open MPI developer's list. - ROMIO is not supported on OpenBSD. You will need to specify the --disable-io-romio flag to configure when building on OpenBSD. OSHMEM Functionality and Features ------------------------------ - All OpenSHMEM-1.0 functionality is supported. MPI Collectives ----------- - The "hierarch" coll component (i.e., an implementation of MPI collective operations) attempts to discover network layers of latency in order to segregate individual "local" and "global" operations as part of the overall collective operation. In this way, network traffic can be reduced -- or possibly even minimized (similar to MagPIe). The current "hierarch" component only separates MPI processes into on- and off-node groups. Hierarch has had sufficient correctness testing, but has not received much performance tuning. As such, hierarch is not activated by default -- it must be enabled manually by setting its priority level to 100: mpirun --mca coll_hierarch_priority 100 ... We would appreciate feedback from the user community about how well hierarch works for your applications. - The "fca" coll component: the Mellanox Fabric Collective Accelerator (FCA) is a solution for offloading collective operations from the MPI process onto Mellanox QDR InfiniBand switch CPUs and HCAs. - The "ML" coll component is an implementation of MPI collective operations that takes advantage of communication hierarchies in modern systems. A ML collective operation is implemented by combining multiple independently progressing collective primitives implemented over different communication hierarchies, hence a ML collective operation is also reffered to as a hierarchical collective operation. The number of collective primitives that are included in a ML collective operation is a function of subgroups(hierarchies). Typically, MPI processes in a single communication hierarchy such as CPU socket, node, or subnet are grouped together into a single subgroup (hierarchy). The number of subgroups are configurable at runtime, and each different collective operation could be configured to have a different of number of subgroups. The component frameworks and components used by\required for a "ML" collective operation. Frameworks: * "sbgp" - Provides functionality for grouping processes into subgroups * "bcol" - Provides collective primitives optimized for a particular communication hierarchy Components: * sbgp components - Provides grouping functionality over a CPU socket ("basesocket"), shared memory ("basesmuma"), Mellanox's ConnectX HCA ("ibnet"), and other interconnects supported by PML ("p2p") * BCOL components - Provides optimized collective primitives for shared memory ("basesmuma"), Mellanox's ConnectX HCA ("iboffload"), and other interconnects supported by PML ("ptpcoll") * "ofacm" - Provides connection manager functionality for InfiniBand communications * "verbs" - Provides commonly used verbs utilities * "netpatterns" - Provides an implementation of algorithm patterns * "commpatterns" - Provides collectives for bootstrap OSHMEM Collectives ----------- - The "fca" scoll component: the Mellanox Fabric Collective Accelerator (FCA) is a solution for offloading collective operations from the MPI process onto Mellanox QDR InfiniBand switch CPUs and HCAs. - The "basic" scoll component: Reference implementation of all OSHMEM collective operations. Network Support --------------- - There are two MPI network models available: "ob1", and "cm". "ob1" uses BTL ("Byte Transfer Layer") components for each supported network. "cm" uses MTL ("Matching Tranport Layer") components for each supported network. - "ob1" supports a variety of networks that can be used in combination with each other (per OS constraints; e.g., there are reports that the GM and OpenFabrics kernel drivers do not operate well together): - OpenFabrics: InfiniBand, iWARP, and RoCE - Loopback (send-to-self) - Myrinet MX and Open-MX - Portals4 - Shared memory - TCP - Intel Phi SCIF - SMCUDA - SCTP - Cisco usNIC - uGNI (Cray Gemini, Ares) - vader (XPMEM) - "cm" supports a smaller number of networks (and they cannot be used together), but may provide better overall MPI performance: - Myrinet MX and Open-MX - InfiniPath PSM - Mellanox MXM - Portals4 Open MPI will, by default, choose to use "cm" when the InfiniPath PSM or the Mellanox MXM MTL can be used. Otherwise, "ob1" will be used and the corresponding BTLs will be selected. Users can force the use of ob1 or cm if desired by setting the "pml" MCA parameter at run-time: shell$ mpirun --mca pml ob1 ... or shell$ mpirun --mca pml cm ... - Similarly, there are two OSHMEM network models available: "yoda", and "ikrit". "yoda" also uses the BTL components for many supported network. "ikrit" interfaces directly with Mellanox MXM. - "yoda" supports a variety of networks that can be used: - OpenFabrics: InfiniBand, iWARP, and RoCE - Loopback (send-to-self) - Shared memory - TCP - "ikrit" only supports Mellanox MXM. - MXM is the Mellanox Messaging Accelerator library utilizing a full range of IB transports to provide the following messaging services to the upper level MPI/OSHMEM libraries: - Usage of all available IB transports - Native RDMA support - Progress thread - Shared memory communication - Hardware-assisted reliability - The usnic BTL is support for Cisco's usNIC device ("userspace NIC") on Cisco UCS servers with the Virtualized Interface Card (VIC). Although the usNIC is accessed via the OpenFabrics / Verbs API stack, this BTL is specific to the Cisco usNIC device. - uGNI is a Cray library for communicating over the Gemini and Ares interconnects. - The OpenFabrics Enterprise Distribution (OFED) software package v1.0 will not work properly with Open MPI v1.2 (and later) due to how its Mellanox InfiniBand plugin driver is created. The problem is fixed OFED v1.1 (and later). - Better memory management support is available for OFED-based transports using the "ummunotify" Linux kernel module. OFED memory managers are necessary for better bandwidth when re-using the same buffers for large messages (e.g., benchmarks and some applications). Unfortunately, the ummunotify module was not accepted by the Linux kernel community (and is still not distributed by OFED). But it still remains the best memory management solution for MPI applications that used the OFED network transports. If Open MPI is able to find the <linux/ummunotify.h> header file, it will build support for ummunotify and include it by default. If MPI processes then find the ummunotify kernel module loaded and active, then their memory managers (which have been shown to be problematic in some cases) will be disabled and ummunotify will be used. Otherwise, the same memory managers from prior versions of Open MPI will be used. The ummunotify Linux kernel module can be downloaded from: http://lwn.net/Articles/343351/ - The use of fork() with OpenFabrics-based networks (i.e., the openib BTL) is only partially supported, and only on Linux kernels >= v2.6.15 with libibverbs v1.1 or later (first released as part of OFED v1.2), per restrictions imposed by the OFED network stack. - Myrinet MX (and Open-MX) support is shared between the 2 internal devices, the MTL and the BTL. The design of the BTL interface in Open MPI assumes that only naive one-sided communication capabilities are provided by the low level communication layers. However, modern communication layers such as Myrinet MX, InfiniPath PSM, or Portals4, natively implement highly-optimized two-sided communication semantics. To leverage these capabilities, Open MPI provides the "cm" PML and corresponding MTL components to transfer messages rather than bytes. The MTL interface implements a shorter code path and lets the low-level network library decide which protocol to use (depending on issues such as message length, internal resources and other parameters specific to the underlying interconnect). However, Open MPI cannot currently use multiple MTL modules at once. In the case of the MX MTL, process loopback and on-node shared memory communications are provided by the MX library. Moreover, the current MX MTL does not support message pipelining resulting in lower performances in case of non-contiguous data-types. The "ob1" PML and BTL components use Open MPI's internal on-node shared memory and process loopback devices for high performance. The BTL interface allows multiple devices to be used simultaneously. For the MX BTL it is recommended that the first segment (which is as a threshold between the eager and the rendezvous protocol) should always be at most 4KB, but there is no further restriction on the size of subsequent fragments. The MX MTL is recommended in the common case for best performance on 10G hardware when most of the data transfers cover contiguous memory layouts. The MX BTL is recommended in all other cases, such as when using multiple interconnects at the same time (including TCP), or transferring non contiguous data-types. - Linux "knem" support is used when the "sm" (shared memory) BTL is compiled with knem support (see the --with-knem configure option) and the knem Linux module is loaded in the running kernel. If the knem Linux kernel module is not loaded, the knem support is (by default) silently deactivated during Open MPI jobs. See http://runtime.bordeaux.inria.fr/knem/ for details on Knem. - XPMEM is used by the vader shared-memory BTL when the XPMEM libraries are installed. XPMEM allows Open MPI to map pages from other processes into the current process' memory space. This allows single-copy semantics for shared memory without the need for a system call. Open MPI Extensions ------------------- - An MPI "extensions" framework has been added (but is not enabled by default). See the "Open MPI API Extensions" section below for more information on compiling and using MPI extensions. - The following extensions are included in this version of Open MPI: - affinity: Provides the OMPI_Affinity_str() routine on retrieving a string that contains what resources a process is bound to. See its man page for more details. - cr: Provides routines to access to checkpoint restart routines. See ompi/mpiext/cr/mpiext_cr_c.h for a listing of availble functions. - example: A non-functional extension; its only purpose is to provide an example for how to create other extensions. =========================================================================== Building Open MPI ----------------- Building Open MPI implies building both the MPI and OpenSHMEM libraries, as such, configure flags that are neither MPI or OSHMEM specific in their names should be regarded as applicable to both libraries. Some pairs of MPI and OSHMEM specific switches may be mutually exclusive e.g. passing both --disable-mpi-fortran --enable-oshmem-fortran will cause configure to abort since the OSHMEM Fortran bindings are dependent upon the MPI bindings being built. Open MPI uses a traditional configure script paired with "make" to build. Typical installs can be of the pattern: --------------------------------------------------------------------------- shell$ ./configure [...options...] shell$ make all install --------------------------------------------------------------------------- There are many available configure options (see "./configure --help" for a full list); a summary of the more commonly used ones follows: INSTALLATION OPTIONS --prefix=<directory> Install Open MPI into the base directory named <directory>. Hence, Open MPI will place its executables in <directory>/bin, its header files in <directory>/include, its libraries in <directory>/lib, etc. --disable-shared By default, libmpi and libshmem are built as a shared library, and all components are built as dynamic shared objects (DSOs). This switch disables this default; it is really only useful when used with --enable-static. Specifically, this option does *not* imply --enable-static; enabling static libraries and disabling shared libraries are two independent options. --enable-static Build libmpi and libshmem as static libraries, and statically link in all components. Note that this option does *not* imply --disable-shared; enabling static libraries and disabling shared libraries are two independent options. Be sure to read the description of --without-memory-manager, below; it may have some effect on --enable-static. --disable-wrapper-rpath By default, the wrapper compilers (e.g., mpicc) will enable "rpath" support in generated executables on systems that support it. That is, they will include a file reference to the location of Open MPI's libraries in the application executable itself. This means that the user does not have to set LD_LIBRARY_PATH to find Open MPI's libraries (e.g., if they are installed in a location that the run-time linker does not search by default). On systems that utilize the GNU ld linker, recent enough versions will actually utilize "runpath" functionality, not "rpath". There is an important difference between the two: "rpath": the location of the Open MPI libraries is hard-coded into the MPI/OSHMEM application and cannot be overridden at run-time. "runpath": the location of the Open MPI libraries is hard-coded into the MPI/OSHMEM application, but can be overridden at run-time by setting the LD_LIBRARY_PATH environment variable. For example, consider that you install Open MPI vA.B.0 and compile/link your MPI/OSHMEM application against it. Later, you install Open MPI vA.B.1 to a different installation prefix (e.g., /opt/openmpi/A.B.1 vs. /opt/openmpi/A.B.0), and you leave the old installation intact. In the rpath case, your MPI application will always use the libraries from your A.B.0 installation. In the runpath case, you can set the LD_LIBRARY_PATH environment variable to point to the A.B.1 installation, and then your MPI application will use those libraries. Note that in both cases, however, if you remove the original A.B.0 installation and set LD_LIBRARY_PATH to point to the A.B.1 installation, your application will use the A.B.1 libraries. This rpath/runpath behavior can be disabled via --disable-wrapper-rpath. --enable-dlopen Build all of Open MPI's components as standalone Dynamic Shared Objects (DSO's) that are loaded at run-time. The opposite of this option, --disable-dlopen, causes two things: 1. All of Open MPI's components will be built as part of Open MPI's normal libraries (e.g., libmpi). 2. Open MPI will not attempt to open any DSO's at run-time. Note that this option does *not* imply that OMPI's libraries will be built as static objects (e.g., libmpi.a). It only specifies the location of OMPI's components: standalone DSOs or folded into the Open MPI libraries. You can control whether Open MPI's libraries are build as static or dynamic via --enable|disable-static and --enable|disable-shared. --with-platform=FILE Load configure options for the build from FILE. Options on the command line that are not in FILE are also used. Options on the command line and in FILE are replaced by what is in FILE. NETWORKING SUPPORT / OPTIONS --with-fca=<directory> Specify the directory where the Mellanox FCA library and header files are located. FCA is the support library for Mellanox QDR switches and HCAs. --with-knem=<directory> Specify the directory where the knem libraries and header files are located. This option is generally only necessary if the knem headers and libraries are not in default compiler/linker search paths. knem is a Linux kernel module that allows direct process-to-process memory copies (optionally using hardware offload), potentially increasing bandwidth for large messages sent between messages on the same server. See http://runtime.bordeaux.inria.fr/knem/ for details. --with-mx=<directory> Specify the directory where the MX libraries and header files are located. This option is generally only necessary if the MX headers and libraries are not in default compiler/linker search paths. MX is the support library for Myrinet-based networks. An open source software package named Open-MX provides the same functionality on Ethernet-based clusters (Open-MX can provide MPI performance improvements compared to TCP messaging). --with-mx-libdir=<directory> Look in directory for the MX libraries. By default, Open MPI will look in <mx directory>/lib and <mx directory>/lib64, which covers most cases. This option is only needed for special configurations. --with-mxm=<directory> Specify the directory where the Mellanox MXM library and header files are located. This option is generally only necessary if the MXM headers and libraries are not in default compiler/linker search paths. MXM is the support library for Mellanox Network adapters. --with-mxm-libdir=<directory> Look in directory for the MXM libraries. By default, Open MPI will look in <mxm directory>/lib and <mxm directory>/lib64, which covers most cases. This option is only needed for special configurations. --with-verbs=<directory> Specify the directory where the verbs (also know as OpenFabrics, and previously known as OpenIB) libraries and header files are located. This option is generally only necessary if the verbs headers and libraries are not in default compiler/linker search paths. "OpenFabrics" refers to operating system bypass networks, such as InfiniBand, usNIC, iWARP, and RoCE (aka "IBoIP"). --with-verbs-libdir=<directory> Look in directory for the verbs libraries. By default, Open MPI will look in <openib directory>/lib and <openib directory>/lib64, which covers most cases. This option is only needed for special configurations. --with-openib=<directory> DEPRECATED synonym for --with-verbs. --with-openib-libdir=<directory> DEPRECATED synonym for --with-verbs-libdir. --with-portals4=<directory> Specify the directory where the Portals4 libraries and header files are located. This option is generally only necessary if the Portals4 headers and libraries are not in default compiler/linker search paths. Portals4 is the support library for Cray interconnects, but is also available on other platforms (e.g., there is a Portals4 library implemented over regular TCP). --with-portals4-libdir=<libdir> Location of libraries to link with for Portals4 support. --with-portals4-max-md-size=SIZE --with-portals4-max-va-size=SIZE Set configuration values for Portals 4 --with-psm=<directory> Specify the directory where the QLogic InfiniPath PSM library and header files are located. This option is generally only necessary if the InfiniPath headers and libraries are not in default compiler/linker search paths. PSM is the support library for QLogic InfiniPath network adapters. --with-psm-libdir=<directory> Look in directory for the PSM libraries. By default, Open MPI will look in <psm directory>/lib and <psm directory>/lib64, which covers most cases. This option is only needed for special configurations. --with-sctp=<directory> Specify the directory where the SCTP libraries and header files are located. This option is generally only necessary if the SCTP headers and libraries are not in default compiler/linker search paths. SCTP is a special network stack over Ethernet networks. --with-sctp-libdir=<directory> Look in directory for the SCTP libraries. By default, Open MPI will look in <sctp directory>/lib and <sctp directory>/lib64, which covers most cases. This option is only needed for special configurations. --with-scif=<dir> Look in directory for Intel SCIF support libraries RUN-TIME SYSTEM SUPPORT --enable-mpirun-prefix-by-default This option forces the "mpirun" command to always behave as if "--prefix $prefix" was present on the command line (where $prefix is the value given to the --prefix option to configure). This prevents most rsh/ssh-based users from needing to modify their shell startup files to set the PATH and/or LD_LIBRARY_PATH for Open MPI on remote nodes. Note, however, that such users may still desire to set PATH -- perhaps even in their shell startup files -- so that executables such as mpicc and mpirun can be found without needing to type long path names. --enable-orterun-prefix-by-default is a synonym for this option. --enable-sensors Enable internal sensors (default: disabled) --enable-orte-static-ports Enable orte static ports for tcp oob. (default: enabled) --with-alps Force the building of for the Cray Alps run-time environment. If Alps support cannot be found, configure will abort. --with-cray-pmi-ext Include Cray PMI2 extensions. --with-loadleveler Force the building of LoadLeveler scheduler support. If LoadLeveler support cannot be found, configure will abort. --with-lsf=<directory> Specify the directory where the LSF libraries and header files are located. This option is generally only necessary if the LSF headers and libraries are not in default compiler/linker search paths. LSF is a resource manager system, frequently used as a batch scheduler in HPC systems. NOTE: If you are using LSF version 7.0.5, you will need to add "LIBS=-ldl" to the configure command line. For example: ./configure LIBS=-ldl --with-lsf ... This workaround should *only* be needed for LSF 7.0.5. --with-lsf-libdir=<directory> Look in directory for the LSF libraries. By default, Open MPI will look in <lsf directory>/lib and <lsf directory>/lib64, which covers most cases. This option is only needed for special configurations. --with-pmi Build PMI support (by default, it is not built). If PMI support cannot be found, configure will abort. If the pmi2.h header is found in addition to pmi.h, then support for PMI2 will be built. --with-slurm Force the building of SLURM scheduler support. If SLURM support cannot be found, configure will abort. --with-sge Specify to build support for the Oracle Grid Engine (OGE) resource manager and/or the open Grid Engine. OGE support is disabled by default; this option must be specified to build OMPI's OGE support. The Oracle Grid Engine (OGE) and open Grid Engine packages are resource manager systems, frequently used as a batch scheduler in HPC systems. --with-tm=<directory> Specify the directory where the TM libraries and header files are located. This option is generally only necessary if the TM headers and libraries are not in default compiler/linker search paths. TM is the support library for the Torque and PBS Pro resource manager systems, both of which are frequently used as a batch scheduler in HPC systems. MISCELLANEOUS SUPPORT LIBRARIES --with-blcr=<directory> Specify the directory where the Berkeley Labs Checkpoint / Restart (BLCR) libraries and header files are located. This option is generally only necessary if the BLCR headers and libraries are not in default compiler/linker search paths. This option is only meaningful if the --with-ft option is also used to active Open MPI's fault tolerance behavior. --with-blcr-libdir=<directory> Look in directory for the BLCR libraries. By default, Open MPI will look in <blcr directory>/lib and <blcr directory>/lib64, which covers most cases. This option is only needed for special configurations. --with-dmtcp=<directory> Specify the directory where the Distributed MultiThreaded Checkpointing (DMTCP) libraries and header files are located. This option is generally only necessary if the DMTCP headers and libraries are not in default compiler/linker search paths. This option is only meaningful if the --with-ft option is also used to active Open MPI's fault tolerance behavior. --with-dmtcp-libdir=<directory> Look in directory for the DMTCP libraries. By default, Open MPI will look in <dmtcp directory>/lib and <dmtcp directory>/lib64, which covers most cases. This option is only needed for special configurations. --with-esmtp=<directory> Specify the directory where the libESMTP libraries and header files are located. This option is generally only necessary of the libESMTP headers and libraries are not included in the default compiler/linker search paths. libESMTP is a support library for sending e-mail. --with-ftb=<directory> Specify the directory where the Fault Tolerant Backplane (FTB) libraries and header files are located. This option is generally only necessary if the BLCR headers and libraries are not in default compiler/linker search paths. --with-ftb-libdir=<directory> Look in directory for the FTB libraries. By default, Open MPI will look in <ftb directory>/lib and <ftb directory>/lib64, which covers most cases. This option is only needed for special configurations. --with-hwloc=<location> Build hwloc support. If <location> is "internal", Open MPI's internal copy of hwloc is used. If <location> is "external", Open MPI will search in default locations for an hwloc installation. Finally, if <location> is a directory, that directory will be searched for a valid hwloc installation, just like other --with-FOO=<directory> configure options. hwloc is a support library that provides processor and memory affinity information for NUMA platforms. --with-hwloc-libdir=<directory> Look in directory for the hwloc libraries. This option is only usable when building Open MPI against an external hwloc installation. Just like other --with-FOO-libdir configure options, this option is only needed for special configurations. --disable-hwloc-pci Disable building hwloc's PCI device-sensing capabilities. On some platforms (e.g., SusE 10 SP1, x86-64), the libpci support library is broken. Open MPI's configure script should usually detect when libpci is not usable due to such brokenness and turn off PCI support, but there may be cases when configure mistakenly enables PCI support in the presence of a broken libpci. These cases may result in "make" failing with warnings about relocation symbols in libpci. The --disable-hwloc-pci switch can be used to force Open MPI to not build hwloc's PCI device-sensing capabilities in these cases. Similarly, if Open MPI incorrectly decides that libpci is broken, you can force Open MPI to build hwloc's PCI device-sensing capabilities by using --enable-hwloc-pci. hwloc can discover PCI devices and locality, which can be useful for Open MPI in assigning message passing resources to MPI processes. --with-libltdl[=VALUE] This option specifies where to find the GNU Libtool libltdl support library. The following VALUEs are permitted: internal: Use Open MPI's internal copy of libltdl. external: Use an external libltdl installation (rely on default compiler and linker paths to find it) <no value>: Same as "internal". <directory>: Specify the location of a specific libltdl installation to use By default (or if --with-libltdl is specified with no VALUE), Open MPI will build and use the copy of libltdl that it has in its source tree. However, if the VALUE is "external", Open MPI will look for the relevant libltdl header file and library in default compiler / linker locations. Or, VALUE can be a directory tree where the libltdl header file and library can be found. This option allows operating systems to include Open MPI and use their default libltdl installation instead of Open MPI's bundled libltdl. Note that this option is ignored if --disable-dlopen is specified. --disable-libompitrace Disable building the simple "libompitrace" library (see note above about libompitrace) --with-valgrind=<directory> Directory where the valgrind software is installed. If Open MPI finds Valgrind's header files, it will include support for Valgrind's memory-checking debugger. Specifically, it will eliminate a lot of false positives from running Valgrind on MPI applications. --disable-vt Disable building VampirTrace. MPI FUNCTIONALITY --with-mpi-param-check(=value) "value" can be one of: always, never, runtime. If --with-mpi-param is not specified, "runtime" is the default. If --with-mpi-param is specified with no value, "always" is used. Using --without-mpi-param-check is equivalent to "never". - always: the parameters of MPI functions are always checked for errors - never: the parameters of MPI functions are never checked for errors - runtime: whether the parameters of MPI functions are checked depends on the value of the MCA parameter mpi_param_check (default: yes). --with-threads=value Since thread support is only partially tested, it is disabled by default. To enable threading, use "--with-threads=posix". This is most useful when combined with --enable-mpi-thread-multiple. --enable-mpi-thread-multiple Allows the MPI thread level MPI_THREAD_MULTIPLE. See --with-threads; this is currently disabled by default. Enabling this feature will automatically --enable-opal-multi-threads. --enable-opal-multi-threads Enables thread lock support in the OPAL and ORTE layers. Does not enable MPI_THREAD_MULTIPLE - see above option for that feature. This is currently disabled by default. --enable-mpi-cxx Enable building the C++ MPI bindings. The MPI C++ bindings were deprecated in MPI-2.2 and deleted in MPI-3.0. Open MPI no longer builds its C++ bindings by default. It is likely that the C++ bindings will be removed from Open MPI at some point in the future. Note that disabling building the C++ bindings does *not* disable all C++ checks during configure. --enable-mpi-java Enable building of an EXPERIMENTAL Java MPI interface (disabled by default). You may also need to specify --with-jdk-dir, --with-jdk-bindir, and/or --with-jdk-headers. See README.JAVA.txt for details. Note that this Java interface is INCOMPLETE (meaning: it does not support all MPI functionality) and LIKELY TO CHANGE. The Open MPI developers would very much like to hear your feedback about this interface. See README.JAVA.txt for more details. --disable-mpi-fortran Disable building the Fortran MPI bindings. Mutually exclusive to --enable-oshmem-fortran. --disable-oshmem-fortran Disable building the Fortran OSHMEM bindings. --enable-mpi-ext(=<list>) Enable Open MPI's non-portable API extensions. If no <list> is specified, all of the extensions are enabled. See "Open MPI API Extensions", below, for more details. --with-io-romio-flags=flags Pass flags to the ROMIO distribution configuration script. This option is usually only necessary to pass parallel-filesystem-specific preprocessor/compiler/linker flags back to the ROMIO system. --enable-sparse-groups Enable the usage of sparse groups. This would save memory significantly especially if you are creating large communicators. (Disabled by default) --without-memory-manager Disable building Open MPI's memory manager. Open MPI's memory manager is usually built on Linux based platforms, and is generally only used for optimizations with some OpenFabrics-based networks (it is not *necessary* for OpenFabrics networks, but some performance loss may be observed without it). However, it may be necessary to disable the memory manager in order to build Open MPI statically. --with-ft=TYPE Specify the type of fault tolerance to enable. Options: LAM (LAM/MPI-like), cr (Checkpoint/Restart). Fault tolerance support is disabled unless this option is specified. --enable-peruse Enable the PERUSE MPI data analysis interface. --enable-heterogeneous Enable support for running on heterogeneous clusters (e.g., machines with different endian representations). Heterogeneous support is disabled by default because it imposes a minor performance penalty. --with-wrapper-cflags=<cflags> --with-wrapper-cxxflags=<cxxflags> --with-wrapper-fflags=<fflags> --with-wrapper-fcflags=<fcflags> --with-wrapper-ldflags=<ldflags> --with-wrapper-libs=<libs> Add the specified flags to the default flags that used are in Open MPI's "wrapper" compilers (e.g., mpicc -- see below for more information about Open MPI's wrapper compilers). By default, Open MPI's wrapper compilers use the same compilers used to build Open MPI and specify an absolute minimum set of additional flags that are necessary to compile/link MPI/OSHMEM applications. These configure options give system administrators the ability to embed additional flags in OMPI's wrapper compilers (which is a local policy decision). The meanings of the different flags are: <cflags>: Flags passed by the mpicc wrapper to the C compiler <cxxflags>: Flags passed by the mpic++ wrapper to the C++ compiler <fcflags>: Flags passed by the mpifort wrapper to the Fortran compiler <ldflags>: Flags passed by all the wrappers to the linker <libs>: Flags passed by all the wrappers to the linker There are other ways to configure Open MPI's wrapper compiler behavior; see the Open MPI FAQ for more information. There are many other options available -- see "./configure --help". Changing the compilers that Open MPI uses to build itself uses the standard Autoconf mechanism of setting special environment variables either before invoking configure or on the configure command line. The following environment variables are recognized by configure: CC - C compiler to use CFLAGS - Compile flags to pass to the C compiler CPPFLAGS - Preprocessor flags to pass to the C compiler CXX - C++ compiler to use CXXFLAGS - Compile flags to pass to the C++ compiler CXXCPPFLAGS - Preprocessor flags to pass to the C++ compiler FC - Fortran compiler to use FCFLAGS - Compile flags to pass to the Fortran compiler LDFLAGS - Linker flags to pass to all compilers LIBS - Libraries to pass to all compilers (it is rarely necessary for users to need to specify additional LIBS) PKG_CONFIG - Path to the pkg-config utility For example: shell$ ./configure CC=mycc CXX=myc++ FC=myfortran ... *** NOTE: We generally suggest using the above command line form for setting different compilers (vs. setting environment variables and then invoking "./configure"). The above form will save all variables and values in the config.log file, which makes post-mortem analysis easier when problems occur. Note that if you intend to compile Open MPI with a "make" other than the default one in your PATH, then you must either set the $MAKE environment variable before invoking Open MPI's configure script, or pass "MAKE=your_make_prog" to configure. For example: shell$ ./configure MAKE=/path/to/my/make ... This could be the case, for instance, if you have a shell alias for "make", or you always type "gmake" out of habit. Failure to tell configure which non-default "make" you will use to compile Open MPI can result in undefined behavior (meaning: don't do that). Note that you may also want to ensure that the value of LD_LIBRARY_PATH is set appropriately (or not at all) for your build (or whatever environment variable is relevant for your operating system). For example, some users have been tripped up by setting to use a non-default Fortran compiler via FC, but then failing to set LD_LIBRARY_PATH to include the directory containing that non-default Fortran compiler's support libraries. This causes Open MPI's configure script to fail when it tries to compile / link / run simple Fortran programs. It is required that the compilers specified be compile and link compatible, meaning that object files created by one compiler must be able to be linked with object files from the other compilers and produce correctly functioning executables. Open MPI supports all the "make" targets that are provided by GNU Automake, such as: all - build the entire Open MPI package install - install Open MPI uninstall - remove all traces of Open MPI from the $prefix clean - clean out the build tree Once Open MPI has been built and installed, it is safe to run "make clean" and/or remove the entire build tree. VPATH and parallel builds are fully supported. Generally speaking, the only thing that users need to do to use Open MPI is ensure that <prefix>/bin is in their PATH and <prefix>/lib is in their LD_LIBRARY_PATH. Users may need to ensure to set the PATH and LD_LIBRARY_PATH in their shell setup files (e.g., .bashrc, .cshrc) so that non-interactive rsh/ssh-based logins will be able to find the Open MPI executables. =========================================================================== Open MPI Version Numbers and Binary Compatibility ------------------------------------------------- Open MPI has two sets of version numbers that are likely of interest to end users / system administrator: * Software version number * Shared library version numbers Both are described below, followed by a discussion of application binary interface (ABI) compatibility implications. Software Version Number ----------------------- Open MPI's version numbers are the union of several different values: major, minor, release, and an optional quantifier. * Major: The major number is the first integer in the version string (e.g., v1.2.3). Changes in the major number typically indicate a significant change in the code base and/or end-user functionality. The major number is always included in the version number. * Minor: The minor number is the second integer in the version string (e.g., v1.2.3). Changes in the minor number typically indicate a incremental change in the code base and/or end-user functionality. The minor number is always included in the version number. Starting with Open MPI v1.3.0, the minor release number took on additional significance (see this wiki page for more details): o Even minor release numbers are part of "super-stable" release series (e.g., v1.4.0). Releases in super stable series are well-tested, time-tested, and mature. Such releases are recomended for production sites. Changes between subsequent releases in super stable series are expected to be fairly small. o Odd minor release numbers are part of "feature" release series (e.g., 1.3.7). Releases in feature releases are well-tested, but they are not necessarily time-tested or as mature as super stable releases. Changes between subsequent releases in feature series may be large. * Release: The release number is the third integer in the version string (e.g., v1.2.3). Changes in the release number typically indicate a bug fix in the code base and/or end-user functionality. If the release number is 0, it is omitted from the version number (e.g., v1.2 has a release number of 0). * Quantifier: Open MPI version numbers sometimes have an arbitrary string affixed to the end of the version number. Common strings include: o aX: Indicates an alpha release. X is an integer indicating the number of the alpha release (e.g., v1.2.3a5 indicates the 5th alpha release of version 1.2.3). o bX: Indicates a beta release. X is an integer indicating the number of the beta release (e.g., v1.2.3b3 indicates the 3rd beta release of version 1.2.3). o rcX: Indicates a release candidate. X is an integer indicating the number of the release candidate (e.g., v1.2.3rc4 indicates the 4th release candidate of version 1.2.3). o rV or hgV: Indicates the Subversion / Mercurial repository number string that the release was made from (V is usually an integer for Subversion releases and usually a string for Mercurial releases). Although all official Open MPI releases are tied to a single, specific Subversion or Mercurial repository number (which can be obtained from the ompi_info command), only some releases have the Subversion / Mercurial repository number in the version number. Development snapshot tarballs, for example, have the Subversion repository included in the version to reflect that they are a development snapshot of an upcoming release (e.g., v1.2.3r1234 indicates a development snapshot of version 1.2.3 corresponding to Subversion repository number 1234). Quantifiers may be mixed together -- for example v1.2.3rc7r2345 indicates a development snapshot of an upcoming 7th release candidate for version 1.2.3 corresponding to Subversion repository number 2345. Shared Library Version Number ----------------------------- Open MPI started using the GNU Libtool shared library versioning scheme with the release of v1.3.2. NOTE: Only official releases of Open MPI adhere to this versioning scheme. "Beta" releases, release candidates, and nightly tarballs, developer snapshots, and Subversion/Mercurial snapshot tarballs likely will all have arbitrary/meaningless shared library version numbers. For deep voodoo technical reasons, only the MPI API libraries were versioned until Open MPI v1.5 was released (i.e., libmpi*so -- libopen-rte.so or libopen-pal.so were not versioned until v1.5). Please see https://svn.open-mpi.org/trac/ompi/ticket/2092 for more details. NOTE: This policy change will cause an ABI incompatibility between MPI applications compiled/linked against the Open MPI v1.4 series; such applications will not be able to upgrade to the Open MPI v1.5 series without re-linking. Sorry folks! The GNU Libtool official documentation details how the versioning scheme works. The quick version is that the shared library versions are a triple of integers: (current,revision,age), or "c:r:a". This triple is not related to the Open MPI software version number. There are six simple rules for updating the values (taken almost verbatim from the Libtool docs): 1. Start with version information of "0:0:0" for each shared library. 2. Update the version information only immediately before a public release of your software. More frequent updates are unnecessary, and only guarantee that the current interface number gets larger faster. 3. If the library source code has changed at all since the last update, then increment revision ("c:r:a" becomes "c:r+1:a"). 4. If any interfaces have been added, removed, or changed since the last update, increment current, and set revision to 0. 5. If any interfaces have been added since the last public release, then increment age. 6. If any interfaces have been removed since the last public release, then set age to 0. Here's how we apply those rules specifically to Open MPI: 1. The above rules do not apply to MCA components (a.k.a. "plugins"); MCA component .so versions stay unspecified. 2. The above rules apply exactly as written to the following libraries starting with Open MPI version v1.5 (prior to v1.5, libopen-pal and libopen-rte were still at 0:0:0 for reasons discussed in bug ticket #2092 https://svn.open-mpi.org/trac/ompi/ticket/2092): * libopen-rte * libopen-pal * libmca_common_* 3. The following libraries use a slightly modified version of the above rules: rules 4, 5, and 6 only apply to the official MPI interfaces (functions, global variables). The rationale for this decision is that the vast majority of our users only care about the official/public MPI interfaces; we therefore want the .so version number to reflect only changes to the official MPI API. Put simply: non-MPI API / internal changes to the MPI-application-facing libraries are irrelevant to pure MPI applications. * libmpi * libmpi_mpifh * libmpi_usempi_tkr * libmpi_usempi_ignore_tkr * libmpi_usempif08 * libmpi_cxx 4. Note, however, that libmpi.so can have its "revision" number incremented if libopen-rte or libopen-pal change (because these two libraries are wholly included in libmpi.so). Specifically: the revision will change, but since we have defined that the only relevant API interface in libmpi.so is the official MPI API, updates to libopen-rte and libopen-pal do not change the "current" or "age" numbers of libmpi.so. Application Binary Interface (ABI) Compatibility ------------------------------------------------ Open MPI provided forward application binary interface (ABI) compatibility for MPI applications starting with v1.3.2. Prior to that version, no ABI guarantees were provided. NOTE: Prior to v1.3.2, subtle and strange failures are almost guaranteed to occur if applications were compiled and linked against shared libraries from one version of Open MPI and then run with another. The Open MPI team strongly discourages making any ABI assumptions before v1.3.2. Starting with v1.3.2, Open MPI provides forward ABI compatibility in all versions of a given feature release series and its corresponding super stable series. For example, on a single platform, an MPI application linked against Open MPI v1.3.2 shared libraries can be updated to point to the shared libraries in any successive v1.3.x or v1.4 release and still work properly (e.g., via the LD_LIBRARY_PATH environment variable or other operating system mechanism). For the v1.7 series, this means that all releases of v1.7.x and v1.8.x will be ABI compatible, per the above definition. Note that in v1.5.4, a fix was applied to the "large" size of the "use mpi" F90 MPI bindings module: two of MPI_SCATTERV's parameters had the wrong type and were corrected. Note that this fix *only* applies if Open MPI was configured with a Fortran 90 compiler and the --with-mpi-f90-size=large configure option. However, in order to preserve the ABI with respect to prior v1.5.x releases, the old/incorrect MPI_SCATTERV interface was preserved in 1.5.5 and all 1.6.x releases. A new/corrected interface was added (note that Fortran 90 has function overloading, similar to C++; hence, both the old and new interface can be accessed via "call MPI_Scatterv(...)"). The incorrect interface was removed in Open MPI v1.7. To be clear: applications that use the old/incorrect MPI_SCATTERV binding will no longer be able to compile properly (*). Developers must fix their applications or use an older version of Open MPI. (*) Note that using this incorrect MPI_SCATTERV interface will not be recongized in v1.7 if you are using gfortran (as of gfortran v4.8). This is because gfortran <=v4.8 does not (yet) have the support Open MPI needs for its new, full-featured "mpi" and "mpi_f08" modules. Hence, Open MPI falls back to the same "mpi" module from the v1.6 series, but the "large" size of that module -- which contains the MPI_SCATTERV interface -- been disabled because it is broken. Further, this "large" sized (old) "mpi" module has been deemed unworthy of fixing because it has been wholly replaced by a new, full-featured "mpi" module. We anticipate supporting gfortran in the new, full-featured module in the future. Open MPI reserves the right to break ABI compatibility at new feature release series. For example, the same MPI application from above (linked against Open MPI v1.3.2 shared libraries) will *not* work with Open MPI v1.5 shared libraries. =========================================================================== Checking Your Open MPI Installation ----------------------------------- The "ompi_info" command can be used to check the status of your Open MPI installation (located in <prefix>/bin/ompi_info). Running it with no arguments provides a summary of information about your Open MPI installation. Note that the ompi_info command is extremely helpful in determining which components are installed as well as listing all the run-time settable parameters that are available in each component (as well as their default values). The following options may be helpful: --all Show a *lot* of information about your Open MPI installation. --parsable Display all the information in an easily grep/cut/awk/sed-able format. --param <framework> <component> A <framework> of "all" and a <component> of "all" will show all parameters to all components. Otherwise, the parameters of all the components in a specific framework, or just the parameters of a specific component can be displayed by using an appropriate <framework> and/or <component> name. --level <level> Show MCA parameters up to level <level> (<level> defaults to 1 if not specified; 9 is the maximum value). Use "ompi_info --param <framework> <component> --level 9" to see *all* MCA parameters for a given component. See "The Modular Component Architecture (MCA)" section, below, for a fuller explanation. Changing the values of these parameters is explained in the "The Modular Component Architecture (MCA)" section, below. When verifying a new Open MPI installation, we recommend running six tests: 1. Use "mpirun" to launch a non-MPI program (e.g., hostname or uptime) across multiple nodes. 2. Use "mpirun" to launch a trivial MPI program that does no MPI communication (e.g., the hello_c program in the examples/ directory in the Open MPI distribution). 3. Use "mpirun" to launch a trivial MPI program that sends and receives a few MPI messages (e.g., the ring_c program in the examples/ directory in the Open MPI distribution). 4. Use "oshrun" to launch a non-OSHMEM program across multiple nodes. 5. Use "oshrun" to launch a trivial MPI program that does no OSHMEM communication (e.g., hello_shmem.c program in the examples/ directory in the Open MPI distribution.) 6. Use "oshrun" to launch a trivial OSHMEM program that puts and gets a few messages. (e.g., the ring_shmem.c in the examples/ directory in the Open MPI distribution.) If you can run all six of these tests successfully, that is a good indication that Open MPI built and installed properly. =========================================================================== Open MPI API Extensions ----------------------- Open MPI contains a framework for extending the MPI API that is available to applications. Each extension is usually a standalone set of functionality that is distinct from other extensions (similar to how Open MPI's plugins are usually unrelated to each other). These extensions provide new functions and/or constants that are available to MPI applications. WARNING: These extensions are neither standard nor portable to other MPI implementations! Compiling the extensions ------------------------ Open MPI extensions are not enabled by default; they must be enabled by Open MPI's configure script. The --enable-mpi-ext command line switch accepts a comma-delimited list of extensions to enable, or, if it is specified without a list, all extensions are enabled. Since extensions are meant to be used by advanced users only, this file does not document which extensions are available or what they do. Look in the ompi/mpiext/ directory to see the extensions; each subdirectory of that directory contains an extension. Each has a README file that describes what it does. Using the extensions -------------------- To reinforce the fact that these extensions are non-standard, you must include a separate header file after <mpi.h> to obtain the function prototypes, constant declarations, etc. For example: ----- #include <mpi.h> #if defined(OPEN_MPI) && OPEN_MPI #include <mpi-ext.h> #endif int main() { MPI_Init(NULL, NULL); #if defined(OPEN_MPI) && OPEN_MPI { char ompi_bound[OMPI_AFFINITY_STRING_MAX]; char current_binding[OMPI_AFFINITY_STRING_MAX]; char exists[OMPI_AFFINITY_STRING_MAX]; OMPI_Affinity_str(OMPI_AFFINITY_LAYOUT_FMT, ompi_bound, current_bindings, exists); } #endif MPI_Finalize(); return 0; } ----- Notice that the Open MPI-specific code is surrounded by the #if statement to ensure that it is only ever compiled by Open MPI. The Open MPI wrapper compilers (mpicc and friends) should automatically insert all relevant compiler and linker flags necessary to use the extensions. No special flags or steps should be necessary compared to "normal" MPI applications. =========================================================================== Compiling Open MPI Applications ------------------------------- Open MPI provides "wrapper" compilers that should be used for compiling MPI and OSHMEM applications: C: mpicc, oshcc C++: mpiCC, oshCC (or mpic++ if your filesystem is case-insensitive) Fortran: mpifort, oshfort For example: shell$ mpicc hello_world_mpi.c -o hello_world_mpi -g shell$ For OSHMEM applications: shell$ oshcc hello_shmem.c -o hello_shmem -g shell$ All the wrapper compilers do is add a variety of compiler and linker flags to the command line and then invoke a back-end compiler. To be specific: the wrapper compilers do not parse source code at all; they are solely command-line manipulators, and have nothing to do with the actual compilation or linking of programs. The end result is an MPI executable that is properly linked to all the relevant libraries. Customizing the behavior of the wrapper compilers is possible (e.g., changing the compiler [not recommended] or specifying additional compiler/linker flags); see the Open MPI FAQ for more information. Alternatively, starting in the Open MPI v1.5 series, Open MPI also installs pkg-config(1) configuration files under $libdir/pkgconfig. If pkg-config is configured to find these files, then compiling / linking Open MPI programs can be performed like this: shell$ gcc hello_world_mpi.c -o hello_world_mpi -g \ `pkg-config ompi-c --cflags --libs` shell$ Open MPI supplies multiple pkg-config(1) configuration files; one for each different wrapper compiler (language): ------------------------------------------------------------------------ ompi Synonym for "ompi-c"; Open MPI applications using the C MPI bindings ompi-c Open MPI applications using the C MPI bindings ompi-cxx Open MPI applications using the C or C++ MPI bindings ompi-fort Open MPI applications using the Fortran MPI bindings ------------------------------------------------------------------------ The following pkg-config(1) configuration files *may* be installed, depending on which command line options were specified to Open MPI's configure script. They are not necessary for MPI applications, but may be used by applications that use Open MPI's lower layer support libraries. orte: Open MPI Run-Time Environment applicaions opal: Open Portable Access Layer applications =========================================================================== Running Open MPI Applications ----------------------------- Open MPI supports both mpirun and mpiexec (they are exactly equivalent) to launch MPI applications. For example: shell$ mpirun -np 2 hello_world_mpi or shell$ mpiexec -np 1 hello_world_mpi : -np 1 hello_world_mpi are equivalent. Some of mpiexec's switches (such as -host and -arch) are not yet functional, although they will not error if you try to use them. The rsh launcher (which defaults to using ssh) accepts a -hostfile parameter (the option "-machinefile" is equivalent); you can specify a -hostfile parameter indicating an standard mpirun-style hostfile (one hostname per line): shell$ mpirun -hostfile my_hostfile -np 2 hello_world_mpi If you intend to run more than one process on a node, the hostfile can use the "slots" attribute. If "slots" is not specified, a count of 1 is assumed. For example, using the following hostfile: --------------------------------------------------------------------------- node1.example.com node2.example.com node3.example.com slots=2 node4.example.com slots=4 --------------------------------------------------------------------------- shell$ mpirun -hostfile my_hostfile -np 8 hello_world_mpi will launch MPI_COMM_WORLD rank 0 on node1, rank 1 on node2, ranks 2 and 3 on node3, and ranks 4 through 7 on node4. Other starters, such as the resource manager / batch scheduling environments, do not require hostfiles (and will ignore the hostfile if it is supplied). They will also launch as many processes as slots have been allocated by the scheduler if no "-np" argument has been provided. For example, running a SLURM job with 8 processors: shell$ salloc -n 8 mpirun a.out The above command will reserve 8 processors and run 1 copy of mpirun, which will, in turn, launch 8 copies of a.out in a single MPI_COMM_WORLD on the processors that were allocated by SLURM. Note that the values of component parameters can be changed on the mpirun / mpiexec command line. This is explained in the section below, "The Modular Component Architecture (MCA)". Open MPI supports oshrun to launch OSHMEM applications. For example: shell$ oshrun -np 2 hello_world_oshmem OSHMEM applications may also be launched directly by resource managers such as SLURM. For example, when OMPI is configured --with-pmi and --with-slurm one may launch OSHMEM applications via srun shell$ srun -N 2 hello_world_oshmem =========================================================================== The Modular Component Architecture (MCA) The MCA is the backbone of Open MPI -- most services and functionality are implemented through MCA components. Here is a list of all the component frameworks in Open MPI: --------------------------------------------------------------------------- MPI component frameworks: ------------------------- allocator - Memory allocator bcol - Base collective operations bml - BTL management layer btl - MPI point-to-point Byte Transfer Layer, used for MPI point-to-point messages on some types of networks coll - MPI collective algorithms crcp - Checkpoint/restart coordination protocol dpm - MPI-2 dynamic process management fbtl - file byte transfer layer: abstraction for individual read/write operations for OMPIO fcoll - collective read and write operations for MPI I/O fs - file system functions for MPI I/O io - MPI-2 I/O mpool - Memory pooling mtl - Matching transport layer, used for MPI point-to-point messages on some types of networks op - Back end computations for intrinsic MPI_Op operators osc - MPI-2 one-sided communications pml - MPI point-to-point management layer pubsub - MPI-2 publish/subscribe management rcache - Memory registration cache rte - Run-time environment operations sbgp - Collective operation sub-group sharedfp - shared file pointer operations for MPI I/O topo - MPI topology routines vprotocol - Protocols for the "v" PML OSHMEM component frameworks: ------------------------- atomic - OSHMEM atomic operations memheap - OSHMEM memory allocators that support the PGAS memory model scoll - OSHMEM collective operations spml - OSHMEM "pml-like" layer: supports one-sided, point-to-point operations Back-end run-time environment (RTE) component frameworks: --------------------------------------------------------- dfs - Distributed filesystem errmgr - RTE error manager ess - RTE environment-specfic services filem - Remote file management grpcomm - RTE group communications iof - I/O forwarding odls - OpenRTE daemon local launch subsystem oob - Out of band messaging plm - Process lifecycle management ras - Resource allocation system rmaps - Resource mapping system rml - RTE message layer routed - Routing table for the RML sensor - Software and hardware health monitoring snapc - Snapshot coordination sstore - Distributed scalable storage state - RTE state machine Miscellaneous frameworks: ------------------------- backtrace - Debugging call stack backtrace support compress - Compression algorithms crs - Checkpoint and restart service db - Internal database support event - Event library (libevent) versioning support hwloc - Hardware locality (hwloc) versioning support if - OS IP interface support installdirs - Installation directory relocation services memchecker - Run-time memory checking memcpy - Memopy copy support memory - Memory management hooks pstat - Process status shmem - Shared memory support (NOT related to OSHMEM) timer - High-resolution timers --------------------------------------------------------------------------- Each framework typically has one or more components that are used at run-time. For example, the btl framework is used by the MPI layer to send bytes across different types underlying networks. The tcp btl, for example, sends messages across TCP-based networks; the openib btl sends messages across OpenFabrics-based networks; the MX btl sends messages across Myrinet MX / Open-MX networks. Each component typically has some tunable parameters that can be changed at run-time. Use the ompi_info command to check a component to see what its tunable parameters are. For example: shell$ ompi_info --param btl tcp shows a some of parameters (and default values) for the tcp btl component. Note that ompi_info only shows a small number a component's MCA parameters by default. Each MCA parameter has a "level" value from 1 to 9, corresponding to the MPI-3 MPI_T tool interface levels. In Open MPI, we have interpreted these nine levels as three groups of three: 1. End user / basic 2. End user / detailed 3. End user / all 4. Application tuner / basic 5. Application tuner / detailed 6. Application tuner / all 7. MPI/OSHMEM developer / basic 8. MPI/OSHMEM developer / detailed 9. MPI/OSHMEM developer / all Here's how the three sub-groups are defined: 1. End user: Generally, these are parameters that are required for correctness, meaning that someone may need to set these just to get their MPI/OSHMEM application to run correctly. 2. Application tuner: Generally, these are parameters that can be used to tweak MPI application performance. 3. MPI/OSHMEM developer: Parameters that either don't fit in the other two, or are specifically intended for debugging / development of Open MPI itself. Each sub-group is broken down into three classifications: 1. Basic: For parameters that everyone in this category will want to see. 2. Detailed: Parameters that are useful, but you probably won't need to change them often. 3. All: All other parameters -- probably including some fairly esoteric parameters. To see *all* available parameters for a given component, specify that ompi_info should use level 9: shell$ ompi_info --param btl tcp --level 9 These values can be overridden at run-time in several ways. At run-time, the following locations are examined (in order) for new values of parameters: 1. <prefix>/etc/openmpi-mca-params.conf This file is intended to set any system-wide default MCA parameter values -- it will apply, by default, to all users who use this Open MPI installation. The default file that is installed contains many comments explaining its format. 2. $HOME/.openmpi/mca-params.conf If this file exists, it should be in the same format as <prefix>/etc/openmpi-mca-params.conf. It is intended to provide per-user default parameter values. 3. environment variables of the form OMPI_MCA_<name> set equal to a <value> Where <name> is the name of the parameter. For example, set the variable named OMPI_MCA_btl_tcp_frag_size to the value 65536 (Bourne-style shells): shell$ OMPI_MCA_btl_tcp_frag_size=65536 shell$ export OMPI_MCA_btl_tcp_frag_size 4. the mpirun/oshrun command line: --mca <name> <value> Where <name> is the name of the parameter. For example: shell$ mpirun --mca btl_tcp_frag_size 65536 -np 2 hello_world_mpi These locations are checked in order. For example, a parameter value passed on the mpirun command line will override an environment variable; an environment variable will override the system-wide defaults. Each component typically activates itself when relavant. For example, the MX component will detect that MX devices are present and will automatically be used for MPI communications. The SLURM component will automatically detect when running inside a SLURM job and activate itself. And so on. Components can be manually activated or deactivated if necessary, of course. The most common components that are manually activated, deactivated, or tuned are the "BTL" components -- components that are used for MPI point-to-point communications on many types common networks. For example, to *only* activate the TCP and "self" (process loopback) components are used for MPI communications, specify them in a comma-delimited list to the "btl" MCA parameter: shell$ mpirun --mca btl tcp,self hello_world_mpi To add shared memory support, add "sm" into the command-delimited list (list order does not matter): shell$ mpirun --mca btl tcp,sm,self hello_world_mpi To specifically deactivate a specific component, the comma-delimited list can be prepended with a "^" to negate it: shell$ mpirun --mca btl ^tcp hello_mpi_world The above command will use any other BTL component other than the tcp component. =========================================================================== Common Questions ---------------- Many common questions about building and using Open MPI are answered on the FAQ: http://www.open-mpi.org/faq/ =========================================================================== Got more questions? ------------------- Found a bug? Got a question? Want to make a suggestion? Want to contribute to Open MPI? Please let us know! When submitting questions and problems, be sure to include as much extra information as possible. This web page details all the information that we request in order to provide assistance: http://www.open-mpi.org/community/help/ User-level questions and comments should generally be sent to the user's mailing list (users@open-mpi.org). Because of spam, only subscribers are allowed to post to this list (ensure that you subscribe with and post from *exactly* the same e-mail address -- joe@example.com is considered different than joe@mycomputer.example.com!). Visit this page to subscribe to the user's list: http://www.open-mpi.org/mailman/listinfo.cgi/users Developer-level bug reports, questions, and comments should generally be sent to the developer's mailing list (devel@open-mpi.org). Please do not post the same question to both lists. As with the user's list, only subscribers are allowed to post to the developer's list. Visit the following web page to subscribe: http://www.open-mpi.org/mailman/listinfo.cgi/devel Make today an Open MPI day!