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Subject: [OMPI users] Openmpi and processor affinity
From: Iftikhar Rathore (irathore_at_[hidden])
Date: 2009-06-02 19:30:59

We are using openmpi version 1.2.8 (packaged with ofed-1.4). I am trying
to run hpl-2.0 (linpak). We have two intel quad core CPU's in all our
server (8 total cores) and all hosts in the hostfile have lines that
look like " slots=8max_slots=8".

Now when I use mpirun (even with --mca mpi_paffinity_alone 1) it does
not keep the affinity, the processes seem to gravitate towards first
four cores (using top and hitting 1). I know I do have MCA paffinity

[root_at_devi DLR_WB_88]# ompi_info | grep paffinity
[] mca: base: component_find: unable to open btl openib: file not found (ignored)
           MCA paffinity: linux (MCA v1.0, API v1.0, Component v1.2.8)

The command line I am using is:

# mpirun -nolocal -np 896 -v --mca mpi_paffinity_alone 1 -hostfile /mnt/apps/hosts/896_8slots /mnt/apps/bin/xhpl

Am I doing something wrong and is there a way to confirm cpu affinity besides hitting "1" on top.

[root_at_devi DLR_WB_88]# mpirun -V
mpirun (Open MPI) 1.2.8

Report bugs to

Iftikhar Rathore
Technical Marketing Engineer
Server Access Virtualization BU.
Cisco Systems, Inc.
Phone:  +1 408 853 5322
Mobile: +1 636 675 2982