Newsgroups: comp.parallel.mpi
From: rmalli@cs.buffalo.edu (Rajkumar E Malli)
Subject: Further clarifications on my prob
Organization: University at Buffalo
Date: 15 May 1997 02:48:10 GMT
Message-ID: <5ldtha$9n7@prometheus.acsu.buffalo.edu>

Hi,

	This is to clarify the IO question on IBM SP-2 that I am
facing... 

My pgm executes cmds in the following manner

Proc #0                Proc #1              Proc #2

printf some info 1  printf some info 2    printf some info 3
fflush(stdout)      fflush(stdout)        fflush(stdout)

MPI_Barrier

printf some info 4

Now, what is happening is that, even though some info 2 and 
some info 3 are sent before some info 4 for being outputted
there is  no guarantee that they will be outputted ahead of
some info 4. The MPI_Barrier cmd just ensures that the o/ps
some  info 1, 2 and 3 are sent to the output device but not
that they will be printed in the same manner.Is it the case
that proc #0, by default, has  more  precedence for i/o and
hence its output is sent ahead of that of others (which are
possibly queued up to be printed) ? If so, is there any way
by which I can assign equal priority for all procs for i/o ?

Thanks.

Rajkumar Malli