Memory allocation in MPI programs

Question

How is memory allocated in slave nodes for execution of MPI programs ? How do slave nodes know the amount of memory to reserve ? What happens when a slave node can't find the data that it wants to access ?

This is not a homework problem , but a question that I tried came up in my mind and could'nt find on googling

Answer 1

With a non-specific question, the best answer you can expect will also be non-specific

When programming using MPI you typically write a single program which is launched (via mpirun/mpiexec, or some batching system eg. torque) on a set of notes.

The master-slave model is but one approach.

The memory allocation is typically under program control, just as you would in any application allocate memory as needed, so to in your MPI program.

As to finding the data, it is often provided to them (directly or indirectly) (by the master process, if the master-slave model is used). If indeed each MPI instance has to "search" for the data it is to be processing, then as with any program that is unable to find what it requires, it should send a suitable error message/status back to the caller (or the master process)

.PMCD.