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Subject: Re: [OMPI users] Roadrunner blasts past the petaflop mark with Open MPI
From: Jeff Squyres (jsquyres_at_[hidden])
Date: 2008-06-17 10:26:52

On Jun 17, 2008, at 10:18 AM, Brad Benton wrote:

> The main run-time parameters used are as follows:
> - For scalable process launch
> routed = binomial

Note that this is a new parameter for OMPI v1.3 -- it has to do with
how non-MPI communications are sent around (e.g., OMPI startup
coordination). More documentation will be coming along on the new
ORTE-level controls for v1.3.

> - To reduce the overhead for IB connections:
> btl_openib_receive_queues = P,128,64,32,32,32:S,2048,1024,128,32:S,
> 12288,1024,128,32:S,65536,1024,128,32

This is also a new parameter for v1.3 -- see the "sneak peak" v1.3
screencast in the videos section (in the OpenFabrics subsection) on
the OMPI web site for a description of what it is/does.

> - Bind processes to computational cores:
> opal_paffinity_alone = 1
> - Leave buffers pinned and registered
> mpi_leave_pinned = 1

These params exist in v1.2.

Jeff Squyres
Cisco Systems