MPICH Release 3.0.4 MPICH is a high-performance and widely portable implementation of the MPI-3.0 standard from the Argonne National Laboratory. This release has all MPI 3.0 functions and features required by the standard with the exception of support for the "external32" portable I/O format and user-defined data representations for I/O. This README file should contain enough information to get you started with MPICH. More extensive installation and user guides can be found in the doc/installguide/install.pdf and doc/userguide/user.pdf files respectively. Additional information regarding the contents of the release can be found in the CHANGES file in the top-level directory, and in the RELEASE_NOTES file, where certain restrictions are detailed. Finally, the MPICH web site, http://www.mcs.anl.gov/research/projects/mpich, contains information on bug fixes and new releases. 1. Getting Started 2. Reporting Installation or Usage Problems 3. Compiler Flags 4. Alternate Channels and Devices 5. Alternate Process Managers 6. Alternate Configure Options 7. Testing the MPICH installation 8. Fault Tolerance 9. Environment Variables 10. Developer Builds 11. Installing MPICH on windows 12. Multiple Fortran compiler support ------------------------------------------------------------------------- 1. Getting Started ================== The following instructions take you through a sequence of steps to get the default configuration (ch3 device, nemesis channel (with TCP and shared memory), Hydra process management) of MPICH up and running. (a) You will need the following prerequisites. - REQUIRED: This tar file mpich-3.0.4.tar.gz - REQUIRED: A C compiler (gcc is sufficient) - OPTIONAL: A C++ compiler, if C++ applications are to be used (g++, etc.). If you do not require support for C++ applications, you can disable this support using the configure option --disable-cxx (configuring MPICH is described in step 1(d) below). - OPTIONAL: A Fortran 77 compiler, if Fortran 77 applications are to be used (gfortran, ifort, etc.). If you do not require support for Fortran 77 applications, you can disable this support using --disable-f77 (configuring MPICH is described in step 1(d) below). - OPTIONAL: A Fortran 90 compiler, if Fortran 90 applications are to be used (gfortran, ifort, etc.). If you do not require support for Fortran 90 applications, you can disable this support using --disable-fc. Note that Fortran 77 support is a prerequisite for Fortran 90 support (configuring MPICH is described in step 1(d) below). Also, you need to know what shell you are using since different shell has different command syntax. Command "echo $SHELL" prints out the current shell used by your terminal program. (b) Unpack the tar file and go to the top level directory: tar xzf mpich-3.0.4.tar.gz cd mpich-3.0.4 If your tar doesn't accept the z option, use gunzip mpich-3.0.4.tar.gz tar xf mpich-3.0.4.tar cd mpich-3.0.4 (c) Choose an installation directory, say /home//mpich-install, which is assumed to non-existent or empty. It will be most convenient if this directory is shared by all of the machines where you intend to run processes. If not, you will have to duplicate it on the other machines after installation. (d) Configure MPICH specifying the installation directory: for csh and tcsh: ./configure --prefix=/home//mpich-install |& tee c.txt for bash and sh: ./configure --prefix=/home//mpich-install 2>&1 | tee c.txt Bourne-like shells, sh and bash, accept "2>&1 |". Csh-like shell, csh and tcsh, accept "|&". If a failure occurs, the configure command will display the error. Most errors are straight-forward to follow. For example, if the configure command fails with: "No Fortran 77 compiler found. If you don't need to build any Fortran programs, you can disable Fortran support using --disable-f77 and --disable-fc. If you do want to build Fortran programs, you need to install a Fortran compiler such as gfortran or ifort before you can proceed." ... it means that you don't have a Fortran compiler :-). You will need to either install one, or disable Fortran support in MPICH. If you are unable to understand what went wrong, please go to step (2) below, for reporting the issue to the MPICH developers and other users. (e) Build MPICH: for csh and tcsh: make |& tee m.txt for bash and sh: make 2>&1 | tee m.txt This step should succeed if there were no problems with the preceding step. Check file m.txt. If there were problems, do a "make clean" and then run make again with V=1. make V=1 |& tee m.txt (for csh and tcsh) OR make V=1 2>&1 | tee m.txt (for bash and sh) Then go to step (2) below, for reporting the issue to the MPICH developers and other users. (f) Install the MPICH commands: for csh and tcsh: make install |& tee mi.txt for bash and sh: make install 2>&1 | tee mi.txt This step collects all required executables and scripts in the bin subdirectory of the directory specified by the prefix argument to configure. (g) Add the bin subdirectory of the installation directory to your path in your startup script (.bashrc for bash, .cshrc for csh, etc.): for csh and tcsh: setenv PATH /home//mpich-install/bin:$PATH for bash and sh: PATH=/home//mpich-install/bin:$PATH ; export PATH Check that everything is in order at this point by doing: which mpicc which mpiexec These commands should display the path to your bin subdirectory of your install directory. IMPORTANT NOTE: The install directory has to be visible at exactly the same path on all machines you want to run your applications on. This is typically achieved by installing MPICH on a shared NFS file-system. If you do not have a shared NFS directory, you will need to manually copy the install directory to all machines at exactly the same location. (h) MPICH uses a process manager for starting MPI applications. The process manager provides the "mpiexec" executable, together with other utility executables. MPICH comes packaged with multiple process managers; the default is called Hydra. Now we will run an MPI job, using the mpiexec command as specified in the MPI standard. There are some examples in the install directory, which you have already put in your path, as well as in the directory mpich-3.0.4/examples. One of them is the classic CPI example, which computes the value of pi by numerical integration in parallel. To run the CPI example with 'n' processes on your local machine, you can use: mpiexec -n ./examples/cpi Test that you can run an 'n' process CPI job on multiple nodes: mpiexec -f machinefile -n ./examples/cpi The 'machinefile' is of the form: host1 host2:2 host3:4 # Random comments host4:1 'host1', 'host2', 'host3' and 'host4' are the hostnames of the machines you want to run the job on. The ':2', ':4', ':1' segments depict the number of processes you want to run on each node. If nothing is specified, ':1' is assumed. More details on interacting with Hydra can be found at http://wiki.mpich.org/mpich/index.php/Using_the_Hydra_Process_Manager If you have completed all of the above steps, you have successfully installed MPICH and run an MPI example. ------------------------------------------------------------------------- 2. Reporting Installation or Usage Problems =========================================== [VERY IMPORTANT: PLEASE COMPRESS ALL FILES BEFORE SENDING THEM TO US. DO NOT SPAM THE MAILING LIST WITH LARGE ATTACHMENTS.] The distribution has been tested by us on a variety of machines in our environments as well as our partner institutes. If you have problems with the installation or usage of MPICH, please follow these steps: 1. First see the Frequently Asked Questions (FAQ) page at http://wiki.mpich.org/mpich/index.php/Frequently_Asked_Questions to see if the problem you are facing has a simple solution. Many common problems and their solutions are listed here. 2. If you cannot find an answer on the FAQ page, look through previous email threads on the mpich-discuss mailing list archive (http://lists.mcs.anl.gov/pipermail/mpich-discuss/). It is likely someone else had a similar problem, which has already been resolved before. 3. If neither of the above steps work, please send an email to mpich-discuss@mcs.anl.gov. You need to subscribe to this list (https://lists.mcs.anl.gov/mailman/listinfo/mpich-discuss) before sending an email. Your email should contain the following files. ONCE AGAIN, PLEASE COMPRESS BEFORE SENDING, AS THE FILES CAN BE LARGE. Note that, depending on which step the build failed, some of the files might not exist. mpich-3.0.4/c.txt (generated in step 1(d) above) mpich-3.0.4/m.txt (generated in step 1(e) above) mpich-3.0.4/mi.txt (generated in step 1(f) above) mpich-3.0.4/config.log (generated in step 1(d) above) mpich-3.0.4/src/openpa/config.log (generated in step 1(d) above) mpich-3.0.4/src/mpl/config.log (generated in step 1(d) above) mpich-3.0.4/src/pm/hydra/config.log (generated in step 1(d) above) mpich-3.0.4/src/pm/hydra/tools/topo/hwloc/hwloc/config.log (generated in step 1(d) above) DID WE MENTION? DO NOT FORGET TO COMPRESS THESE FILES! If you have compiled MPICH and are having trouble running an application, please provide the output of the following command in your email. mpiexec -info Finally, please include the actual error you are seeing when running the application, including the mpiexec command used, and the host file. If possible, please try to reproduce the error with a smaller application or benchmark and send that along in your bug report. 4. If you have found a bug in MPICH, we request that you report it at our bug tracking system: (https://trac.mpich.org/projects/mpich/newticket). Even if you believe you have found a bug, we recommend you sending an email to mpich-discuss@mcs.anl.gov first. ------------------------------------------------------------------------- 3. Compiler Flags ================= MPICH allows several sets of compiler flags to be used. The first three sets are configure-time options for MPICH, while the fourth is only relevant when compiling applications with mpicc and friends. (a) CFLAGS, CPPFLAGS, CXXFLAGS, FFLAGS, FCFLAGS, LDFLAGS and LIBS (abbreviated as xFLAGS): Setting these flags would result in the MPICH library being compiled/linked with these flags and the flags internally being used in mpicc and friends. (b) MPICHLIB_CFLAGS, MPICHLIB_CPPFLAGS, MPICHLIB_CXXFLAGS, MPICHLIB_FFLAGS, MPICHLIB_FCFLAGS, MPICHLIB_LDFLAGS and MPICHLIB_LIBS (abbreviated as MPICHLIB_xFLAGS): Setting these flags would result in the MPICH library being compiled/linked with these flags. However, these flags will *not* be used by mpicc and friends. (c) MPICH_MAKE_CFLAGS: Setting these flags would result in MPICH's configure tests to not use these flags, but the makefile's to use them. This is a temporary hack for certain cases that advanced developers might be interested in, but which break existing configure tests (e.g., -Werror). These are NOT recommended for regular users. (d) MPICH_MPICC_FLAGS, MPICH_MPICPP_FLAGS, MPICH_MPICXX_FLAGS, MPICH_MPIF77_FLAGS, MPICH_MPIFC_FLAGS, MPICH_LDFLAGS and MPICH_LIBS (abbreviated as MPICH_MPIX_FLAGS): These flags do *not* affect the compilation of the MPICH library itself, but will be internally used by mpicc and friends. +--------------------------------------------------------------------+ | | | | | | MPICH library | mpicc and friends | | | | | +--------------------+----------------------+------------------------+ | | | | | xFLAGS | Yes | Yes | | | | | +--------------------+----------------------+------------------------+ | | | | | MPICHLIB_xFLAGS | Yes | No | | | | | +--------------------+----------------------+------------------------+ | | | | | MPICH_MAKE_xFLAGS | Yes | No | | | | | +--------------------+----------------------+------------------------+ | | | | | MPICH_MPIX_FLAGS | No | Yes | | | | | +--------------------+----------------------+------------------------+ All these flags can be set as part of configure command or through environment variables. Default flags -------------- By default, MPICH automatically adds certain compiler optimizations to MPICHLIB_CFLAGS. The currently used optimization level is -O2. ** IMPORTANT NOTE: Remember that this only affects the compilation of the MPICH library and is not used in the wrappers (mpicc and friends) that are used to compile your applications or other libraries. This optimization level can be changed with the --enable-fast option passed to configure. For example, to build an MPICH environment with -O3 for all language bindings, one can simply do: ./configure --enable-fast=O3 Or to disable all compiler optimizations, one can do: ./configure --disable-fast For more details of --enable-fast, see the output of "configure --help". Examples -------- Example 1: ./configure --disable-fast MPICHLIB_CFLAGS=-O3 MPICHLIB_FFLAGS=-O3 \ MPICHLIB_CXXFLAGS=-O3 MPICHLIB_FCFLAGS=-O3 This will cause the MPICH libraries to be built with -O3, and -O3 will *not* be included in the mpicc and other MPI wrapper script. Example 2: ./configure --disable-fast CFLAGS=-O3 FFLAGS=-O3 CXXFLAGS=-O3 FCFLAGS=-O3 This will cause the MPICH libraries to be built with -O3, and -O3 will be included in the mpicc and other MPI wrapper script. Example 3: There are certain compiler flags that should not be used with MPICH's configure, e.g. gcc's -Werror, which would confuse configure and cause certain configure tests to fail to detect the correct system features. To use -Werror in building MPICH libraries, you can pass the compiler flags during the make step through the Makefile variable MPICH_MAKE_CFLAGS as follows: make MPICH_MAKE_CFLAGS="-Wall -Werror" The content of MPICH_MAKE_CFLAGS is appended to the CFLAGS in all relevant Makefiles. ------------------------------------------------------------------------- 4. Alternate Channels and Devices ================================= The communication mechanisms in MPICH are called "devices". MPICH supports ch3 (default), as well as many third-party devices that are released and maintained by other institutes such as osu_ch3 (from Ohio State University for InfiniBand and iWARP), ch_mx (from Myricom for Myrinet MX), etc. ************************************* ch3 device ********** The ch3 device contains different internal communication options called "channels". We currently support nemesis (default) and sock channels. nemesis channel --------------- Nemesis provides communication using different networks (tcp, mx) as well as various shared-memory optimizations. To configure MPICH with nemesis, you can use the following configure option: --with-device=ch3:nemesis The TCP network module gets configured in by default. To specify a different network module such as MX, you can use: --with-device=ch3:nemesis:mx If the MX include files and libraries are not in the normal search paths, you can specify them with the following options: --with-mx-include= and --with-mx-lib= ... or the if lib/ and include/ are in the same directory, you can use the following option: --with-mx= If the MX libraries are shared libraries, they need to be in the shared library search path. This can be done by adding the path to /etc/ld.so.conf, or by setting the LD_LIBRARY_PATH variable in your .bashrc (or .tcshrc) file. It's also possible to set the shared library search path in the binary. If you're using gcc, you can do this by adding LD_LIBRARY_PATH=/path/to/lib (and) LDFLAGS="-Wl,-rpath -Wl,/path/to/lib" ... as arguments to configure. By default, MX allows for only eight endpoints per node causing ch3:nemesis:mx to give initialization errors with greater than 8 processes on the same node (this is an MX error and not an inherent limitation in the MPICH/Nemesis design). If needed, this can be set to a higher number when MX is loaded. We recommend the user to contact help@myri.com for details on how to do this. Shared-memory optimizations are enabled by default to improve performance for multi-processor/multi-core platforms. They can be disabled (at the cost of performance) either by setting the environment variable MPICH_NO_LOCAL to 1, or using the following configure option: --enable-nemesis-dbg-nolocal The --with-shared-memory= configure option allows you to choose how Nemesis allocates shared memory. The options are "auto", "sysv", and "mmap". Using "sysv" will allocate shared memory using the System V shmget(), shmat(), etc. functions. Using "mmap" will allocate shared memory by creating a file (in /dev/shm if it exists, otherwise /tmp), then mmap() the file. The default is "auto". Note that System V shared memory has limits on the size of shared memory segments so using this for Nemesis may limit the number of processes that can be started on a single node. sock channel ------------ sock is the traditional TCP sockets based communication channel. It uses TCP/IP sockets for all communication including intra-node communication. So, though the performance of this channel is worse than that of nemesis, it should work on almost every platform. This channel can be configured using the following option: --with-device=ch3:sock pamid device ************ This is the device used on the IBM Blue Gene/Q system. The following configure options can be used: ./configure --host=powerpc64-bgq-linux --target=powerpc64-bgq-linux --build=powerpc64-linux-gnu --with-device=pamid:BGQ --with-file-system=bg+bglockless --enable-timer-type=device --with-fwrapname=fmpich --with-cross=src/mpid/pamid/cross/bgq8 --with-pm=none --enable-timing=no --disable-collchk --disable-graphics --disable-rlog --disable-sample --disable-rpath --with-aint-size=8 --with-assert-level=2 --enable-fast=O3 --enable-error-messages --disable-debuginfo --enable-thread-cs=per-object --enable-handle-allocation=tls --enable-refcount=lock-free --disable-predefined-refcount CC=powerpc64-bgq-linux-gcc CXX=powerpc64-bgq-linux-g++ F77=powerpc64-bgq-linux-gfortran FC=powerpc64-bgq-linux-gfortran ------------------------------------------------------------------------- 5. Alternate Process Managers ============================= hydra ----- Hydra is the default process management framework that uses existing daemons on nodes (e.g., ssh, pbs, slurm, sge) to start MPI processes. More information on Hydra can be found at http://wiki.mpich.org/mpich/index.php/Using_the_Hydra_Process_Manager mpd --- MPD was the traditional process manager in MPICH. The file mpich-3.0.4/src/pm/mpd/README has more information about interactive commands for managing the ring of MPDs. The MPD process manager is now deprecated. smpd ---- SMPD is a process manager for interoperability between Microsoft Windows and UNIX, where some processes are running on Windows and others are running on a variant of UNIX. For more information, please see mpich-3.0.4/src/pm/smpd/README. gforker ------- gforker is a process manager that creates processes on a single machine, by having mpiexec directly fork and exec them. gforker is mostly meant as a research platform and for debugging purposes, as it is only meant for single-node systems. slurm ----- SLURM is an external process manager not distributed with MPICH. MPICH's default process manager, hydra, has native support for slurm and you can directly use it in slurm environments (it will automatically detect slurm and use slurm capabilities). However, if you want to use the slurm provided "srun" process manager, you can use the "--with-pmi=slurm --with-pm=no" option with configure. Note that the "srun" process manager that comes with slurm uses an older PMI standard which does not have some of the performance enhancements that hydra provides in slurm environments. ------------------------------------------------------------------------- 6. Alternate Configure Options ============================== MPICH has a number of other features. If you are exploring MPICH as part of a development project, you might want to tweak the MPICH build with the following configure options. A complete list of configuration options can be found using: ./configure --help However, for your convenience, we list a few important options here: Performance Options: --enable-fast - Turns off error checking and collection of internal timing information --enable-timing=no - Turns off just the collection of internal timing information --enable-ndebug - Turns on NDEBUG, which disables asserts. This is a subset of the optimizations provided by enable-fast, but is useful in environments where the user wishes to retain the debug symbols, e.g., this can be combined with the --enable-g option. MPI Features: --enable-romio - Build the ROMIO implementation of MPI-IO (enabled by default). --with-file-system - When used with --enable-romio, specifies filesystems ROMIO should support. They can be specified by passing them in a '+'-delimited list: (e.g., --with-file-system="pvfs+nfs+ufs"). If you have installed version 2 of the PVFS file system, you can use the '--with-pvfs2=' configure option to specify where libraries, headers, and utilities have been installed. If you have added the pvfs utilities to your PATH, then ROMIO will detect this and build support for PVFS automatically. --enable-threads - Build MPICH with support for multi-threaded applications. Only the sock and nemesis channels support MPI_THREAD_MULTIPLE. --with-thread-package - When used with --enable-threads, this option specifies the thread package to use. This option defaults to "posix". At the moment, only POSIX threads are supported on UNIX platforms. We plan to support Solaris threads in the future. Language bindings: --enable-f77 - Build the Fortran 77 bindings (enabled by default). --enable-fc - Build the Fortran 90 bindings (enabled by default). --enable-cxx - Build the C++ bindings (enabled by default). Shared library support: --enable-shared - Enable shared library support. Note that "rpath" linking is used by default in stock MPICH distributions. Re-running ./autogen.sh with a patched libtool can eliminate rpath usage. See http://wiki.debian.org/RpathIssue for more info. Cross compilation: --with-cross=filename - Provide values for the tests that required running a program, such as the tests that configure uses to determine the sizes of the basic types. This should be a fine in Bourne shell format containing variable assignment of the form CROSS_SIZEOF_INT=2 for all of the CROSS_xxx variables. Error checking and reporting: --enable-error-checking=level - Control the amount of error checking. Currently, only "no" and "all" is supported; all is the default. --enable-error-messages=level - Control the aount of detail in error messages. By default, MPICH provides instance-specific error messages; but, with this option, MPICH can be configured to provide less detailed messages. This may be desirable on small systems, such as clusters built from game consoles or high-density massively parallel systems. This is still under active development. Compilation options for development: --enable-g=value - Controls the amount of debugging information collected by the code. The most useful choice here is dbg, which compiles with -g. --enable-coverage - An experimental option that enables GNU coverage analysis. --with-logging=name - Select a logging library for recording the timings of the internal routines. We have used this to understand the performance of the internals of MPICH. More information on the logging options, capabilities and usage can be found in doc/logging/logging.pdf. --enable-timer-type=name - Select the timer to use for MPI_Wtime and internal timestamps. name may be one of: gethrtime - Solaris timer (Solaris systems only) clock_gettime - Posix timer (where available) gettimeofday - Most Unix systems linux86_cycle - Linux x86; returns cycle counts, not time in seconds* linuxalpha_cycle - Like linux86_cycle, but for Linux Alpha* gcc_ia64_cycle - IPF ar.itc timer* device - The timer is provided by the device *Note that the cycle timers are intended to be used by MPICH developers for internal low-level timing. Normal users should not use these as they are not guaranteed to be accurate in certain situations. ------------------------------------------------------------------------- 7. Testing the MPICH installation ================================== To test MPICH, we package the MPICH test suite in the MPICH distribution. You can run the test suite using: make testing The results summary will be placed in test/summary.xml ------------------------------------------------------------------------- 8. Fault Tolerance ================== MPICH has some tolerance to process failures, and supports checkpointing and restart. Tolerance to Process Failures ----------------------------- The features described in this section should be considered experimental. Which means that they have not been fully tested, and the behavior may change in future releases. The below notes are some guidelines on what can be expected in this feature: - ERROR RETURNS: Communication failures in MPICH are not fatal errors. This means that if the user sets the error handler to MPI_ERRORS_RETURN, MPICH will return an appropriate error code in the event of a communication failure. When a process detects a failure when communicating with another process, it will consider the other process as having failed and will no longer attempt to communicate with that process. The user can, however, continue making communication calls to other processes. Any outstanding send or receive operations to a failed process, or wildcard receives (i.e., with MPI_ANY_SOURCE) posted to communicators with a failed process, will be immediately completed with an appropriate error code. - COLLECTIVES: For collective operations performed on communicators with a failed process, the collective would return an error on some, but not necessarily all processes. A collective call returning MPI_SUCCESS on a given process means that the part of the collective performed by that process has been successful. - PROCESS MANAGER: If used with the hydra process manager, hydra will detect failed processes and notify the MPICH library. Users can query the list of failed processes using MPIX_Comm_group_failed(). This functions returns a group consisting of the failed processes in the communicator. The function MPIX_Comm_remote_group_failed() is provided for querying failed processes in the remote processes of an intercommunicator. Note that hydra by default will abort the entire application when any process terminates before calling MPI_Finalize. In order to allow an application to continue running despite failed processes, you will need to pass the -disable-auto-cleanup option to mpiexec. - FAILURE NOTIFICATION: THIS IS AN UNSUPPORTED FEATURE AND WILL ALMOST CERTAINLY CHANGE IN THE FUTURE! In the current release, hydra notifies the MPICH library of failed processes by sending a SIGUSR1 signal. The application can catch this signal to be notified of failed processes. If the application replaces the library's signal handler with its own, the application must be sure to call the library's handler from it's own handler. Note that you cannot call any MPI function from inside a signal handler. Checkpoint and Restart ---------------------- MPICH supports checkpointing and restart fault-tolerance using BLCR. CONFIGURATION First, you need to have BLCR version 0.8.2 or later installed on your machine. If it's installed in the default system location, you don't need to do anything. If BLCR is not installed in the default system location, you'll need to tell MPICH's configure where to find it. You might also need to set the LD_LIBRARY_PATH environment variable so that BLCR's shared libraries can be found. In this case add the following options to your configure command: --with-blcr= LD_LIBRARY_PATH=/lib where is the directory where BLCR has been installed (whatever was specified in --prefix when BLCR was configured). After it's configured compile as usual (e.g., make; make install). Note, checkpointing is only supported with the Hydra process manager. VERIFYING CHECKPOINTING SUPPORT Make sure MPICH is correctly configured with BLCR. You can do this using: mpiexec -info This should display 'BLCR' under 'Checkpointing libraries available'. CHECKPOINTING THE APPLICATION There are two ways to cause the application to checkpoint. You can ask mpiexec to periodically checkpoint the application using the mpiexec option -ckpoint-interval (seconds): mpiexec -ckpointlib blcr -ckpoint-prefix /tmp/app.ckpoint \ -ckpoint-interval 3600 -f hosts -n 4 ./app Alternatively, you can also manually force checkpointing by sending a SIGUSR1 signal to mpiexec. The checkpoint/restart parameters can also be controlled with the environment variables HYDRA_CKPOINTLIB, HYDRA_CKPOINT_PREFIX and HYDRA_CKPOINT_INTERVAL. To restart a process: mpiexec -ckpointlib blcr -ckpoint-prefix /tmp/app.ckpoint -f hosts -n 4 -ckpoint-num where is the checkpoint number you want to restart from. These instructions can also be found on the MPICH wiki: http://wiki.mpich.org/mpich/index.php/Checkpointing ------------------------------------------------------------------------- 9. Environment Variables ======================== MPICH provides several environment variables that have different purposes. Many of these environment variables are listed in the README.envvar file. Some more are listed below. MPICH_ASYNC_PROGRESS - Initiates a spare thread to provide asynchronous progress. This improves progress semantics for all MPI operations including point-to-point, collective, one-sided operations and I/O. Setting this variable would increase the thread-safety level to MPI_THREAD_MULTIPLE. While this improves the progress semantics, it might cause a small amount of performance overhead for regular MPI operations. ************************************ MPICH_NAMEPUB_DIR - Allows the user to override where the publish and lookup information is placed for connect/accept based applications. ------------------------------------------------------------------------- 10. Developer Builds ==================== For MPICH developers who want to directly work on the svn, there are a few additional steps involved (people using the release tarballs do not have to follow these steps). Details about these steps can be found here: http://wiki.mpich.org/mpich/index.php/Getting_And_Building_MPICH ------------------------------------------------------------------------- 11. Installing MPICH on Windows ================================ Here are the instructions for setting up MPICH on a Windows machine: (a) Install: Microsoft Developer Studio 2003 or later Intel Fortran 8.0 or later cygwin choose the dos file format option install perl and svn (b) Checkout mpich: Bring up a command prompt. (replace "yourname" with your MCS login name): svn co https://svn.mcs.anl.gov/repos/mpi/mpich2/trunk mpich (c) Generate *.h.in Bring up a cygwin bash shell. cd mpich ./autogen.sh exit (d) Execute winconfigure.wsf (e) Open Developer Studio open mpich\mpich.sln build the ch3sockDebug mpich solution build the ch3sockDebug mpichs project build the ch3sockRelease mpich solution build the ch3sockRelease mpichs project build the Debug mpich solution build the Release mpich solution build the fortDebug mpich solution build the fortRelease mpich solution build the gfortDebug mpich solution build the gfortRelease mpich solution build the sfortDebug mpich solution build the sfortRelease mpich solution (f) Open a command prompt cd to mpich\maint execute "makegcclibs.bat" (g) Open another Developer Studio instance open mpich\examples\examples.sln build the Release target of the cpi project (h) Return to Developer Studio with the mpich solution set the version numbers in the Installer project build the Installer mpich solution (i) Test and distribute mpich\maint\ReleaseMSI\mpich.msi mpich.msi can be renamed, eg mpich-1.1.msi (j) To install the launcher: Copy smpd.exe to a local directory on all the nodes. Log on to each node as an administrator and execute "smpd.exe -install" (k) Compile and run an MPI application: Compile an mpi application. Use mpi.h from mpich\src\include\win32 and mpi.lib in mpich\lib Place your executable along with the mpich dlls somewhere accessable to all the machines. Execute a job by running something like: mpiexec -n 3 myapp.exe ------------------------------------------------------------------------- 12. Multiple Fortran compiler support ===================================== If the C compiler that is used to build MPICH libraries supports both multiple weak symbols and multiple aliases of common symbols, the Fortran 77 binding can support multiple Fortran compilers. The multiple weak symbols support allow MPICH to provide different name mangling scheme (of subroutine names) required by differen Fortran compilers. The multiple aliases of common symbols support enables MPICH to equal different common block symbols of the MPI Fortran constant, e.g. MPI_IN_PLACE, MPI_STATUS_IGNORE. So they are understood by different Fortran compilers. Since the support of multiple aliases of common symbols is new/experimental, users can disable the feature by using configure option --disable-multi-aliases if it causes any undesirable effect, e.g. linker warnings of different sizes of common symbols, MPIFCMB* (the warning should be harmless). We have only tested this support on a limited set of platforms/compilers. On linux, if the C compiler that builds MPICH is either gcc or icc, the above support will be enabled by configure. At the time of this writing, pgcc does not seem to have this multiple aliases of common symbols, so configure will detect the deficiency and disable the feature automatically. The tested Fortran compiler includes GNU Forran compilers(gfortan, g77), Intel Fortran compiler(ifort), Portland Group Fortran compilers(pgf77, pgf90), Absoft Fortran compilers (af77, af90), and IBM XL fortran compiler(xlf). What this mean is that if mpich is built by gcc/gfortran, the resulting mpich library can be used to link a Fortran program compiled/linked by another fortran compiler, say pgf77, say through mpif77 -f77=pgf77. As long as the Fortran program is linked without any errors by one of these compilers, the program shall be running fine.