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I have downloaded an LU Decomposition program from the following link http://www.cs.nyu.edu/wanghua/course...el/h3/mpi_lu.c and the programming is running very well...The reason for me writing this thread is that can any one help me with getting the time of execution spent on the processors of the nodes connected in the cluster so that it aid me in getting the statistical value from my cluster.

Kindly, help me as I don't know much about MPI Programming, all I want is the amount of time spent on each processor of nodes in the cluster for the above program.

asheeshr
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Sushil Ks
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    Besides using timing functions as High Performance Mark suggested, there are a host of profiling tools for MPI - from lightweight solutions like _mpiP_ to sophisticated tracing libraries like _VampirTrace_ and various trace analysis GUIs (e.g. _Vampir_, if you have access to it, as it is commercially distributed software). MPICH includes its own tracing mechanism and the _Jumpshot_ GUI (part of MPE). – Hristo Iliev Feb 12 '13 at 17:24

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There are at least 2 ways of getting the times you seek, or at least a close approximation to them.

If you have a job management system installed on your cluster (if you don't you should have) then I expect that it will log the time spent on each node by each process involved in your computation. Certainly Grid Engine keeps this data in its accounting file and provides the utility qacct for inspecting that file. I'd be very surprised to learn that the other widely used job management systems don't offer similar data and functions.

You could edit your program and insert mpi_wtime calls at the critical points. Of course, like all MPI routines, this can only be called after mpi_init and before mpi_finalize; you would have to make other arrangements for timing the parts of your code which lie outside the scope of MPI. (on most MPI implementations that do not support clock synchronisation calls to mpi_wtime are possible before mpi_init and after mpi_finalize was called, as there mpi_wtime is simply a wrapper around the system timer routines, but that's not guaranteed to be portable)

Hristo Iliev
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High Performance Mark
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