Newsgroups: comp.parallel.pvm
From: eddemain@neumann.uwaterloo.ca (Erik Demaine)
Subject: Merging of message --> performance plus??
Organization: University of Waterloo
Date: Fri, 11 Oct 1996 18:35:37 GMT
Message-ID: <Dz4JnD.Hs0@undergrad.math.uwaterloo.ca>

Hello,

I have a program that does synchronous communications like:

        Sender          Receiver
           --------------->         control message (data available)
           <---------------         control message (request data)
           --------------->         control message (commit send)
           --------------->         data

Right now I'm testing this method (with empty data, but still sent) as
compared to just

        Sender          Receiver
           --------------->         data

via pvm_send.

Tests indicate that:

   - with PvmNoRoute, the sync. operation takes four times as long as
     the async. one.  Fine!

   - with PvmRouteDirect, the sync. operation takes a little over three times
     as long as the async. one.  Neat!

Is this expected behavior?  Note that I'm running two processes on a single
processor, so I'm really just looking at latency.

If so, this is pretty neat.  Comments would be appreciated.

Erik
-- 
Erik Demaine                 ()  e-mail: eddemain@neumann.uwaterloo.ca
Dept. of Computer Science    \/  URL: http://barrow.uwaterloo.ca/~eddemain/
University of Waterloo       /\  PGP key: finger me.  "Flying is the art of
Waterloo, ON Canada N2L 3G1  ()  falling and not hitting the ground" -Adams

