From: lusk@donner.mcs.anl.gov (Rusty Lusk)
Newsgroups: comp.parallel.mpi
Subject: Re: Building MPICH on SMP: ch_shmem or ch_p4 (?)
Date: 10 May 1999 16:35:37 GMT
Organization: Argonne National Laboratory
Message-Id: <7h71sp$6uo$1@milo.mcs.anl.gov>
References: <7g9jq9$trq$1@vvv.srcc.msu.su> <37285C51.71E7C9CF@hotbot.com>
    <7gphqb$fja$1@nnrp1.dejanews.com> <37314EA1.F1CFD3D5@hotbot.com>
    <7gsrh4$g6b$1@nnrp1.deja.com>
Xref: ukc comp.parallel.mpi:5064


In article <7gsrh4$g6b$1@nnrp1.deja.com>, matt@mail.ssc.usm.edu writes:
|> Two questions, first
|> If you don't use mpirun how do you tell the computer how many processors to
|> use??  Is that like a NUM_THREADS variable??

With the ch_shmem device, you can use mpirun -np 4

If you are using multiple SMPs, and want to use shared memory inside
the box and sockets between boxes, and hence are using the ch_p4
device configured with -comm=shared, you will need a "procgroup file",
as described in the User's Guide, to place processes.

|> second, I keep getting stuff about the profiling objects not found
|> 
|> comm_util.o(.text+0x35f): undefined reference to `PMPI_Sendrecv'
|> comm_util.o(.text+0x3ae): undefined reference to `PMPI_Bcast'

Be sure you are linking with -lpmpich.  If you are using mpicc, mpif77,
mpiCC, or mpif90 to compile and link (recommended) then the right libraries
will be added for you automatically.

Rusty Lusk