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Debugging LAM/MPI Applications
the front-end node. TotalView assumes that the address can be resolved by
using a name that is:
front-end-hostname-io.
For example, if the hostname of the front-end is fred, the servers will connect
to fred-io.
The systems at the IBM Blue Gene Capacity on Demand follow this convention. If you
are executing programs there, you will not need to set the TotalView variables described
in the rest of this section.
If the front-end cannot resolve this name, you must supply the name of the
interface using the –local_interface command-line option or by setting the
bluegene_io_interface TotalView variable. (This variable is described in the
Chapter 4 of the TotalView Reference Guide.)
Because the same version of TotalView must be able to debug both Power-
Linux programs (for example, mpirun) and Blue Gene programs, TotalView
uses a Blue Gene-specific server launch string. You can define this launch
string by setting the bluegene_server_launch_string TotalView variable or
command-line option.
You must set this variable in a tvdrc file. This differs from other TotalView launch
strings, which you can set using the File > Preferences Dialog Box.
The default value for the bluegene_server_launch_string variable is:
–callback %L –set_pw %P -verbosity %V %F
In this string, %L is the address of the front-end node interface used by the
servers. The other substitution arguments have the same meaning as they
do in a normal server launch string. These substitution arguments are discussed
in Chapter 7 of the TotalView Reference Guide.
Debugging LAM/MPI Applications
In many cases, you can bypass the procedure described in this section. For more information,
see “Debugging MPI Programs” on page 98.
The following is a description of the LAM/MPI implementation of the MPI
standard. Here are the first two paragraphs of Chapter 2 of the “LAM/MPI
User’s Guide”. You can find You can obtain this document by going to the
LAM documentation page, which is: http://www.lam-mpi.org/using/docs/.
“LAM/MPI is a high-performance, freely available, open source implementation
of the MPI standard that is researched, developed, and maintained
at the Open Systems Lab at Indiana University. LAM/MPI supports all of
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