From: Paul Kapinos <email@example.com>
To: Randolph Pullen <firstname.lastname@example.org>; Open MPI Users <email@example.com>
Sent: Tuesday, 28 August 2012 6:13 PM
Subject: Re: [OMPI users] Infiniband performance Problem and stalling
after reading this:
On 08/28/12 04:26, Randolph Pullen wrote:
> - On occasions it seems to stall indefinately, waiting on a single receive.
would make a blind guess: are you aware about IB card parameters for registered memory?http://www.open-mpi.org/faq/?category=openfabrics#ib-low-reg-mem
"Waiting forever" for a single operation is one of symptoms of the problem especially in 1.5.3.
P.S. the lower performance with 'big' chinks is known phenomenon, cf.http://www.scl.ameslab.gov/netpipe/
(image on bottom of the page). But the chunk size of 64k is fairly small
-- Dipl.-Inform. Paul Kapinos - High Performance Computing,
RWTH Aachen University, Center for Computing and Communication
Seffenter Weg 23, D 52074 Aachen (Germany)
Tel: +49 241/80-24915