Hi Jeff,

 Thanks for taking care of this.

Here is what I got on a worker node:

> mpirun --mca mpi_paffinity_alone 1 /opt/software/SGI/hwloc/1.1rc6r3028/bin/hwloc-bind --get
0x00000001

 Is this what is expected, please ? Or should I try yet another command ?

 Thanks,   Regards,   Gilbert.



Le 7 janv. 11 à 15:35, Jeff Squyres a écrit :

On Jan 6, 2011, at 11:23 PM, Gilbert Grosdidier wrote:

lstopo
Machine (35GB)
NUMANode L#0 (P#0 18GB) + Socket L#0 + L3 L#0 (8192KB)
  L2 L#0 (256KB) + L1 L#0 (32KB) + Core L#0
    PU L#0 (P#0)
    PU L#1 (P#8)
  L2 L#1 (256KB) + L1 L#1 (32KB) + Core L#1
    PU L#2 (P#1)
    PU L#3 (P#9)
  L2 L#2 (256KB) + L1 L#2 (32KB) + Core L#2
    PU L#4 (P#2)
    PU L#5 (P#10)
  L2 L#3 (256KB) + L1 L#3 (32KB) + Core L#3
    PU L#6 (P#3)
    PU L#7 (P#11)
[snip]

Well, this might disprove my theory.  :-\  The OS indexing is not contiguous on the hyperthreads, so I might be wrong about what happened here.  Try this:

mpirun --mca mpi_paffinity_alone 1 hwloc-bind --get

You can even run that on just one node; let's see what you get.  This will tell us what each process is *actually* bound to.  hwloc-bind --get will report a bitmask of the P#'s from above.  So if we see 001, 010, 011, ...etc, then my theory of OMPI binding 1 proc per hyperthread (vs. 1 proc per core) is incorrect.

--
Jeff Squyres
jsquyres@cisco.com
For corporate legal information go to:
http://www.cisco.com/web/about/doing_business/legal/cri/


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