Here are some things to investigate:

This is almost always caused by send or recv requests that are either unmatched or not completed. An unmatched request is any blocking send for which a corresponding recv is never posted. An incomplete request is any nonblocking send or recv request that was never freed by a call to MPI_Test(), MPI_Wait(), or MPI_Request_free().

Common examples are applications that call MPI_Isend() and then use internal means to determine when it is safe to reuse the send buffer. These applications never call MPI_Wait() . You can fix such codes easily by inserting a call to MPI_Request_free() immediately after all such isend operations, or by adding a call to MPI_Wait() at a later place in the code, prior to the point at which the send buffer must be reused.

If your application was compiled with the Open64 compiler, make sure you follow the instructions about using the Open64 compiler in combination with MPI/OpenMP applications descibed in “Compiling and Linking MPI Programs” in Chapter 3.

There are two types of cases in which the MPI library reports an error concerning MPI_REQUEST_MAX. The error reported by the MPI library distinguishes these.

MPI has run out of unexpected request entries;
the current allocation level is: XXXXXX

The program is sending so many unexpected large messages (greater than 64 bytes) to a process that internal limits in the MPI library have been exceeded. The options here are to increase the number of allowable requests via the MPI_REQUEST_MAX shell variable, or to modify the application.

MPI has run out of request entries; 
the current allocation level is: MPI_REQUEST_MAX = XXXXX

You might have an application problem. You almost certainly are calling MPI_Isend() or MPI_Irecv() and not completing or freeing your request objects. You need to use MPI_Request_free(), as described in the previous section.

All stdout and stderr is line-buffered, which means that mpirun does not print any partial lines of output. This sometimes causes problems for codes that prompt the user for input parameters but do not end their prompts with a newline character. The only solution for this is to append a newline character to each prompt.

You can set the MPI_UNBUFFERED_STDIO environment variable to disable line-buffering. For more information, see the MPI(1) and mpirun(1) man pages.

MPT RPMs are included in the SGI Performance Suite releases. In addition, you can obtain MPT RPMs from the SGI Support website at

http://support.sgi.com

See the intro_shmem(3) man page.

At MPI job start-up, MPI calls the SHMEM library to cross-map all user static memory on all MPI processes to provide optimization opportunities. The result is large virtual memory usage. The ps(1) command's SIZE statistic is telling you the amount of virtual address space being used, not the amount of memory being consumed. Even if all of the pages that you could reference were faulted in, most of the virtual address regions point to multiply-mapped (shared) data regions, and even in that case, actual per-process memory usage would be far lower than that indicated by SIZE.

This message means that something happened while mpirun was trying to launch your application, which caused it to fail before all of the MPI processes were able to handshake with it.

The mpirun command directs arrayd to launch a master process on each host and listens on a socket for those masters to connect back to it. Since the masters are children of arrayd, arrayd traps SIGCHLD and passes that signal back to mpirun whenever one of the masters terminates. If mpirun receives a signal before it has established connections with every host in the job, it knows that something has gone wrong.

In general, the rule to follow is to run mpirun on your tool and then the tool on your application. Do not try to run the tool on mpirun. Also, because of the way that mpirun sets up stdio, seeing the output from your tool might require a bit of effort. The most ideal case is when the tool directly supports an option to redirect its output to a file. In general, this is the recommended way to mix tools with mpirun . Of course, not all tools (for example, dplace) support such an option. However, it is usually possible to make it work by wrapping a shell script around the tool and having the script do the redirection, as in the following example:

> cat myscript 
     #!/bin/sh 
     setenv MPI_DSM_OFF 
     dplace -verbose a.out 2> outfile 
     > mpirun -np 4 myscript 
     hello world from process 0 
     hello world from process 1 
     hello world from process 2 
     hello world from process 3 
     > cat outfile 
     there are now 1 threads 
     Setting up policies and initial thread. 
     Migration is off. 
     Data placement policy is PlacementDefault. 
     Creating data PM. 
     Data pagesize is 16k. 
     Setting data PM. 
     Creating stack PM. 
     Stack pagesize is 16k. 
     Stack placement policy is PlacementDefault. 
     Setting stack PM. 
     there are now 2 threads 
     there are now 3 threads 
     there are now 4 threads 
     there are now 5 threads 

More information can be found in the MPI(1) man page in descriptions of the MPI_COREDUMP and MPI_COREDUMP_DEBUGGER environment variables.