Eugene Loh wrote:
RightCFD wrote:
Date: Thu, 29 Oct 2009 15:45:06 -0400
From: Brock Palen mailto:bro...@umich.edu>>
Subject: Re: [OMPI users] mpi functions are slow when first called and
become normal afterwards
To: Open MPI Users mailto:us...@open-m
RightCFD wrote:
Date:
Thu, 29 Oct 2009 15:45:06 -0400
From: Brock Palen <bro...@umich.edu>
Subject: Re: [OMPI users] mpi functions are slow when first called and
become normal afterwards
To: Open MPI Users <us...@open-mpi.org>
Message-ID: <890cc430-68b0-4307
: Thu, 29 Oct 2009 15:45:06 -0400
From: Brock Palen
Subject: Re: [OMPI users] mpi functions are slow when first called and
become normal afterwards
To: Open MPI Users
Message-ID: <890cc430-68b0-4307-8260-24a6fadae...@umich.edu>
Content-Type: text/plain; charset=US-ASCII; format=flowed
>
> Date: Thu, 29 Oct 2009 15:45:06 -0400
> From: Brock Palen
> Subject: Re: [OMPI users] mpi functions are slow when first called and
> become normal afterwards
> To: Open MPI Users
> Message-ID: <890cc430-68b0-4307-8260-24a6fadae...@umich.edu>
> Conten
When MPI_Bcast and MPI_Reduce are called for the first time, they
are very slow. But after that, they run at normal and stable speed.
Is there anybody out there who have encountered such problem? If you
need any other information, please let me know and I'll provide.
Thanks in advance.
Th
We installed a linux cluster recently. The OS is Ubuntu 8.04. The
network is infiniband. We run a simple MPI program to compute the
value of pi. The program follows three stages: MPI_Bcast, computation
and MPI_Reduce. We measure the elapsed time on computation and
communication, respectivel
