On Jun 2, 2010, at 1:31 PM, guillaume ranquet wrote:

> > ~/openmpi-1.4.2-bin/bin/mpirun --mca btl openib,sm,self --mca pml ^cm 
> > ~/bwlat/mpi_helloworld
> 
> the first command seems to be wrong, I had an error message:
> MCA framework parameters can only take a single negation operator

Correct.  Scott's 2nd one should be tried.

Open MPI has 2 flavors of MX support: a BTL and an MTL.  You need to disable 
both of them. His 2nd command effectively does that:

1. cm is the PML is uses MTLs; by disabling cm, you're disabling all MTLs -- 
including the MX MTL
2. By specifically listing openib,sm,self, you're only allowing those BTLs to 
be used (not the MX BTL).

> granquet@bordeplage-9 ~/openmpi-1.4.2 $ ~/openmpi-1.4.2-bin/bin/mpirun
> - --mca btl openib,sm,self --mca pml ^cm ~/bwlat/mpi_helloworld
> Hello world from process 0 of 1
> granquet@bordeplage-9 ~/openmpi-1.4.2 $

Good.

> > Ok, there is no segfault when it can't find IB.

I'm not sure I follow this comment.

>From your prior mails:

- there's no segv when ptmalloc is disabled at run-time via the env var
- there's no segv when MX is completed disabled (both BTL and MTL)

What happens if you run with only MX?  I *assume* that works with no segv...?

It might be interesting to see what happens if you run with:

mpirun --mca btl mx,openib,sm,self --mca pml ^cm --mca mpi_leave_pinned 0 
...yourapp...

This should run with both verbs and MX, and the memory manager is in place at 
run-time, but it isn't being used to track memory.  That's slightly different 
than having the memory manager in place at run-time *and* using it to track 
memory.

> the goal is to run the same version everywhere on every nodes (for the
> sake of simplicity).
> the current plans were targeting 1.4.1.
> I don't think our users would mind upgrading to 1.4.2.

FWIW, it *is* the same version on all nodes -- you're just running with 
different MCA parameter values.  Also FWIW, the sysadmin can hide these MCA 
params in a system-level file so that users don't have to deal with them, if 
that works for you.  See:

    http://www.open-mpi.org/faq/?category=tuning#setting-mca-params

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


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