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<DIV dir=ltr align=left><SPAN class=835203717-25102006><FONT face=Arial
color=#0000ff size=2>Are you using a single MPI_Comm_spawn with maxprocs=4 to
spawn the four process? In that case, I believe they will get spread across the
nodes. If you use four separate MPI_Comm_spawns with maxprocs=1, they will get
spawned on the same node.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=835203717-25102006><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=835203717-25102006><FONT face=Arial
color=#0000ff size=2>Rajeev</FONT></SPAN></DIV><BR>
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<FONT face=Tahoma size=2><B>From:</B> owner-mpich-discuss@mcs.anl.gov
[mailto:owner-mpich-discuss@mcs.anl.gov] <B>On Behalf Of </B>Hrant P.
Hratchian<BR><B>Sent:</B> Tuesday, October 24, 2006 11:27 PM<BR><B>To:</B>
mpich-discuss@mcs.anl.gov<BR><B>Subject:</B> [MPICH] Using MPI_COMM_SPAWN
correctly<BR></FONT><BR></DIV>
<DIV></DIV>I'm a basic MPI user and I've built a set of code that uses
MPI_COMM_SPAWN. The way that the code runs the master process runs on
only 1 process while the slave processes use n processes.<BR><BR>I have a
mpd.hosts file that includes three machines: node_1, node_2, and node_3.
mpdtrace confirms that the loop has been established and runs over all three
machines. To run the code I execute the following on node_1:
<BR><BR>mpiexec -n 1 Prog_Master <A href="http://test.in">test.in</A>
>& test.mpilog &<BR><BR>Prog_Master spawns 4 processes using
MPI_COMM_SPAWN. Rather than spreading the 4 spawned processes across the
three machines listed in mpd.hosts (where the loop is running), all 4 spawned
processes run on node_1.<BR><BR>Am I doing something wrong here?<BR><BR>Thanks
in advance.<BR>HPH<BR clear=all><BR>-- <BR>Hrant P. Hratchian, Ph.D.<BR>E. R.
Davidson Fellow <BR>Department of Chemistry<BR>Indiana
University<BR>Bloomington, Indiana 47405-7102<BR>812.856.0829<BR><A
href="mailto:hhratchi@indiana.edu">hhratchi@indiana.edu</A>
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