Newsgroups: comp.parallel.pvm
From: zrauk01@decap2.zdv.uni-tuebingen.de (Uwe Koch)
Subject: Problems with PVM 3.3.5 on Cray EL and other architectures
Organization: InterNetNews at ZDV Uni-Tuebingen
Date: 13 Dec 94 16:26:07 GMT
Message-ID: <zrauk01.787335967@decap2>

Hello PVM-Experts!

Currently I'm doing some simple measurements: Send a message from one
process to another and back and look how long it takes. (Of course,
not just once, but more often due to statistics..)

Here is a code fragment of my program:
          call pvmfinitsend(
c     &            PVMDEFAULT, info )
     &            PVMDATARAW, info )
c     &            PVMDATAINPLACE, info )
          call pvmfpack( STRING, token, len(j), stride, info )
          call pvmfsend( tids(1), msgtag, info )
          call pvmfrecv( tids(1), msgtag, info )
          call pvmfunpack( STRING, token, len(j), stride, info )

(this is from the master)

It doesn't work with PVMDATAINPLACE on cray, but does work on CNVX,HPPA,PGON.
Has anybody else experienced this (non-)feature of PVM on Cray EL's?


Next Problem: To speed things up I tried to use pvmfpsend:
          call pvmfpsend(tids(1), msgtag,token,len(j),STRING,info)
          write (*,'(a,7I8)') 'sm:',tids(0),msgtag,len(j),
     &           ntid,ntag,ncnt,info
          call pvmfprecv(tids(1), msgtag,token,len(j),STRING,
     &                  ntid,ntag,ncnt,info)
          write (*,'(a,7I8)') 'rm:',tids(0),msgtag,len(j),
     &           ntid,ntag,ncnt,info

instead of the fragment above. The result was, that on every send or
receive I got -2 in info (PvmBadParam). Not only on cray, but also on
all other architectures (HPPA,CNVX,PGON). But the nntime example program
(which uses pvm_psend in C) run fine.

Any hints?

Thanks for your help!

-uwe

--
U. Koch, Computing Center, University of Tuebingen, Germany


