Basic HTML version of Foils prepared 2 September 1997

Foil 22 Implementation of MPSHIFT(+1, SOURCE,DEST)

From CPS615 Laplace Example -- Programming Models and Performance CPS615 Basic Simulation Track for Computational Science -- Fall Semester 97. by Geoffrey C. Fox
1 Consider for example, shift to right
2 Then Processors 0 .. Nproc-2 Send to right
    • Processors 1 .. Nproc-1 Receive from left
3 We can't necessarily send all messages and then receive all messages. "Standard" send can be "blocking" i.e. will not return unless receive completed by destination processor. In this case, we can deadlock as all "hang" after send, waiting for receive
4 So we are more careful
in Table To:

© on Tue Oct 7 1997