[MPICH2-dev] running out of fd's?

[Brian R. Toonen]

Nick,

The maximum number of file descriptors per process on your machine is 10240
and the maximum number for all processes is 12288.  These numbers were
obtained using the following command.

% sysctl -a | grep maxfiles
kern.exec: unknown type returned
kern.maxfiles = 12288
kern.maxfilesperproc = 10240
kern.maxfiles: 12288
kern.maxfilesperproc: 10240

Assuming you are using (t)csh as your shell, you can increase your limit per
process to the maximum by adding "limit descriptors 10240" to your .cshrc
file.  If you use (ba)sh, then adding "ulimit -n 10240" to your .profile
should do the trick.

--brian

|-----Original Message-----
|From: owner-mpich2-dev at mcs.anl.gov [mailto:owner-mpich2-dev at mcs.anl.gov] On
|Behalf Of Rob Ross
|Sent: Wednesday, January 30, 2008 13:53
|To: Darius Buntinas
|Cc: Nicholas Karonis; mpich2-dev at mcs.anl.gov; Brian Toonen
|Subject: Re: [MPICH2-dev] running out of fd's?
|
|default socket max is i think 1024? -- rob
|
|On Jan 30, 2008, at 1:26 PM, Darius Buntinas wrote:
|
|> I bet it's gforker.  It creates O(N) sockets for stdio, etc.  Try
|> mpd and see if that helps.
|>
|> -d
|>
|> On 01/30/2008 01:06 PM, Nicholas Karonis wrote:
|>> Hi,
|>> I just installed MPICH2-1.0.6 on Mac OS X 10.5.1 (i.e., Leopard).
|>> I configured it with the gforker and it was all compiled using
|>> Gnu's C and C++ compilers that came with the developer tools
|>> on the Mac OS X disk.
|>> The build seem to go OK and so I tried testing it with a small
|>> ring program (source at bottom).  When I run the ring with -np 75
|>> all is OK but when I increase it to 100 I get an error message:
|>> /* running with 75, all OK */
|>> mpro% mpiexec -np 75 ring
|>> nprocs 75 received 75
|>> /* attempting to run with 100, problem :-( */
|>> mpro% mpiexec -np 100 ring
|>> Error in system call select: Bad file descriptor
|>> mpro%
|>> Any suggestions?
|>> Thanks in advance,
|>> Nick
|>> --- app source
|>> mpro% cat ring.c
|>> #include "mpi.h"
|>> #include <stdio.h>
|>> #include <stdlib.h>
|>> int main(int argc, char *argv[])
|>> {
|>>    int nprocs, myid;
|>>    int val;
|>>    MPI_Status st;
|>>    MPI_Init(&argc, &argv);
|>>    MPI_Comm_size(MPI_COMM_WORLD, &nprocs);
|>>    if (nprocs > 1)
|>>    {
|>>    MPI_Comm_rank(MPI_COMM_WORLD, &myid);
|>>    if (myid == 0)
|>>    {
|>>        val = 1;
|>>        MPI_Send(&val, 1, MPI_INT, 1, 0, MPI_COMM_WORLD);
|>>        MPI_Recv(&val, 1, MPI_INT, nprocs-1, 0, MPI_COMM_WORLD, &st);
|>>        printf("nprocs %d received %d\n", nprocs, val);
|>>    }
|>>    else
|>>    {
|>>        MPI_Recv(&val, 1, MPI_INT, myid-1, 0, MPI_COMM_WORLD, &st);
|>>        val ++;
|>>        MPI_Send(&val, 1, MPI_INT, (myid+1)%nprocs, 0,
|>> MPI_COMM_WORLD);
|>>    } /* endif */
|>>    } /* endif */
|>>    MPI_Finalize();
|>>    exit(0);
|>> } /* end main() */
|>> mpro%
|>