p4 Arguments for the ch_p4 Device


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When using the ch_p4 device, a number of command-line arguments may be used to control the behavior of the program.



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p4 Debugging


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If your configuration of mpich used -device=ch_p4, then some of the p4 debugging capabilities are available to you. The most useful of these are the command line arguments to the application program. Thus

    mpirun -np 10 myprog -p4dbg 20 -p4rdbg 20 

results in program tracing information at a level of 20 being written to stdout during execution. For more information about what is printed at what levels, see the p4 Users' Guide [1].

If one specifies -p4norem on the command line, mpirun will not actually start the processes. The master process prints a message suggesting how the user can do it. The point of this option is to enable the user to start the remote processes under his favorite debugger, for instance. The option only makes sense when processes are being started remotely, such as on a workstation network. Note that this is an argument to the program, not to mpirun. For example, to run myprog this way, use

     mpirun -np 4 myprog -p4norem 



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Setting the Working Directory for the p4 Device


Up: p4 Arguments for the ch_p4 Device Next: Command-line arguments for the application program Previous: p4 Debugging

By default, the working directory for processes running remotely with ch_p4 device is the same as that of the executable. To specify the working directly, use -p4wdir as follows:


     mpirun -np 4 myprog -p4wdir myrundir 



Up: p4 Arguments for the ch_p4 Device Next: Command-line arguments for the application program Previous: p4 Debugging