[mvapich-discuss] MVAPICH1 Latency Tuning

[Sayantan Sur]

Hi Hideyuki,

On Wed, Mar 10, 2010 at 2:34 PM, Hideyuki Jitsumoto
<jitumoto at gsic.titech.ac.jp> wrote:
> Hello,
>
> I want to reduce the latency and memory use with MVAPICH1.
> My MPI application has:
> - < 128KB message size
> - 4 peer connection for one process
>
> I make the temporary paramfile as attached file.
> Please tell me other tuning point or wrong parameter on this file.

Thanks for your question. It is an important question. We would be
happy to assist you with tuning MVAPICH for your application.

I took a quick look at the param file. Based on what I see, I think
some parameters relating to rendezvous protocol are not optimal at
all. We need to understand your application a little bit more to be
able to help you better. So, a few questions:

1) Do you know how many concurrent outstanding sends your application
has during its iteration steps?
2) Can you share a code snippet of the inner loop of your application?
3) Which InfiniBand adapters do you have on your cluster?
4) What is the node type, number of cores?

This will help us to send you a better send of parameters in the next few days.

>
> Thank you,
> Hideyuki
> --
> Sincerely Yours,
> Hideyuki Jitsumoto (jitumoto at gsic.titech.ac.jp)
> Tokyo Institute of Technology
> Global Scientific Information and Computing center (Matsuoka Lab.)
>
> _______________________________________________
> mvapich-discuss mailing list
> mvapich-discuss at cse.ohio-state.edu
> http://mail.cse.ohio-state.edu/mailman/listinfo/mvapich-discuss
>
>



-- 
Sayantan Sur

Research Scientist
Department of Computer Science
The Ohio State University.