(j3.2006) (SC22WG5.3745) Nick's MPI non-blocking proposal

Aleksandar Donev donev1 at llnl.gov
Thu Dec 4 18:14:28 EST 2008


Bill Long wrote:

> Actually, I find it massively confusing. 
No surprise, since you are confused about what Nick means by I/O. Nick's 
proposal is meant to cover send/receive as well. It is I/O in common 
computer science lingo, which I am aware is different from Fortran (file 
I/O) and some other practices (likely Cray's internal terminology). Just 
replace I/O with "data transfer" and you should be less confused reading 
his draft.

Note Wikipedia definition:
"In computing, input/output, or I/O, refers to the communication between 
an information processing system (such as a computer), and the outside 
world – possibly a human, or another information processing 
system...Devices for communication between computers, such as modems and 
network cards, typically serve for both input and output."
Surely a send/receive via a network card is I/O. Maybe on a Cray it is 
all the same "information processing system" so it is sending data to 
itself rather than the "outside". Ultimately, it makes no difference. It 
is about transferring data to/from something external to the program, 
which is what is important to Fortran.

Best,
Aleks


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