Open MPI logo

Open MPI User's Mailing List Archives

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

Subject: Re: [OMPI users] Sending relatively large messages with high frequency
From: Prentice Bisbal (prentice_at_[hidden])
Date: 2010-02-25 15:45:41


Amr Hassan wrote:
> Thanks alot for your reply,
>
> I'm using blocking Send and Receive. All the clients are sending data
> and the server is receive the messages from the clients with
> MPI_ANY_SOURCE as the sender. Do you think there is a race condition
> near this pattern?
>
> I searched a lot and used totalview but I couldn't detect such case. I
> really appreciate if you send me a link or give an example of a possible
> race condition in that scenario .
>
> Also, when I partition the message into smaller parts (send in sequence
> - all the other clients wait until the send finish) it works fine. is
> that exclude the race condition?
>

It sounds like, when sending the large messages, you are putting more
data into a buffer than it can hold. When you break the messages up into
 smaller sizes, you're not overflowing the buffer.

Are you using MPI_Pack, by any chance?

-- 
Prentice Bisbal
Linux Software Support Specialist/System Administrator
School of Natural Sciences
Institute for Advanced Study
Princeton, NJ