[MPICH] MPI I/O Reading 2gb or more of data

[James S Perrin]

Hi,
	I've come across a problem and need to confirm the intended behaviour 
of MPICH2 and the MPI spec when it come to reading (or handling in 
general) more 2GB or more of data.

	Specifically I reading contiguous data using MPI_File_read, if I need 
to read MAX_INT elements or more I chunk the reads over MAX_INT.

If nelements*sizeof(element) < 2GB then every thing is fine, ie I can 
read 2^31-1 of chars. However is size of datatype is > 2 and therefore 
I'm reading more than 2GB of actual data then no values seem to be read 
but the return value from MPI_File_read is MPI_SUCCESS.

	I've changed my code to make sure the actual amount of data read is 
less than 2gb but what should be the correct behaviour?

	Using 1.05p4.

Regards
James
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James S. Perrin,                  | email: james.perrin at manchester.ac.uk
Manchester Visualization Centre,  | web:   www.mc.manchester.ac.uk
Kilburn Building, The University, | tel:   +44 161 275 6945
Manchester, England. M13 9PL.     | fax:   +44 161 275 0637
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