User`s guide

Cray XMT™ Programming Environment User’s Guide
The mtarun command uses a default configuration file, .mtarunrc, which exists
in your home directory. You can modify this file to include any mtarun options,
separated by spaces. The configurations in this file are overridden by options that
you use from the command line.
To monitor process or CPU usage by your program, you use mtatop. For more
information about using mtarun to run the program or mtatop to monitor the
program, see
Cray XMT System Management.
Note: When an application that was built for tracing is running, an intermediate
process runs to flush trace data back to the service partition as the tracing buffers
fill. To ensure that all tracing data is captured, the mtarun that launched the
application will not exit until this tracing process completes. Depending on the
amount of data that needs to be flushed, and the speed of the underlying file
system, mtarun may not exit for some time after the application has completed. If
you kill the mtarun process, in the belief that it is hung, you may get incomplete
tracing data. For more information on partial tracing data see Partial Tracing in the
Cray XMT Performance Tools User's Guide.
8.2 User Runtime Environment Variables
There are a number of environment variables that you can use with the user runtime
known as MTA_PARAMS. You can use these environment variables for debugging,
dumping registers, setting the number of streams, setting maximums for processors
and ready pools, and so on.
For csh, use the following command:
% setenv MTA_PARAMS "param1 param2"
For example, to set the maximum number of processors and to prevent streams from
being reserved for the debugger, set MTA_PARAMS by using the following command:
% setenv MTA_PARAMS "num_procs 100 no_prereserve"
For a bash shell, use the following command:
% export MTA_PARAMS="param1 param2"
For example, to set the maximum number of processors to two and indicate that the
program must wait for a debugger to attach in the event of a poison, you use the
following command on a bash shell:
% export MTA_PARAMS="num_procs 2 debug_data_prot"
For a list of environment variables that you can set, see Appendix G, MTA_PARAMS
on page 143.
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