Open MPI logo

Open MPI User's Mailing List Archives

  |   Home   |   Support   |   FAQ   |   all Open MPI User's mailing list

Subject: Re: [OMPI users] Loopback Communication
From: Giovanni Davide Vergine (verginegiovanni_at_[hidden])
Date: 2008-03-01 07:57:54

Loopback communication it's shared memory copy, of course.
Even if it would be implemented with socket() and other network
syscalls, kernel will do finally only memory copying.

Il giorno 01/mar/08, alle ore 00:25, Elvedin Trnjanin ha scritto:

> I'm using a "ping pong" program to approximate bandwidth and latency
> of
> various messages sizes and I notice when doing various transfers (eg.
> async) that the maximum bandwidth isn't the system's maximum
> bandwidth.
> I've looked through the FAQ and I haven't noticed this being covered
> but
> how does OpenMPI handle loopback communication? Is it still over a
> network interconnect or some sort of shared memory copy?
> - Elvedin
> _______________________________________________
> users mailing list
> users_at_[hidden]