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From: Jeff Squyres (jsquyres_at_[hidden])
Date: 2006-07-28 17:16:26


Marcelo --

Can you send your code that is failing? I'm unable to reproduce with some
toy programs here.

I also notice that you're running a somewhat old version of and OMPI SVN
checkout of the trunk. Can you update to the most recent version? The
trunk is not guaranteed to be stable, and we did have some stability
problems recently -- you might want to upgrade to the most recent version
(today seems to be ok) and/or try one of the nightly or prerelease tarballs
in the 1.1 branch.

On 7/26/06 6:18 PM, "Marcelo Stival" <marstival_at_[hidden]> wrote:

> Hi,
>
> I got a problem with ompi when sending large number of messages from
> process A to process B.
> Process A only send... and B only receive (the buffers are reused)
>
> int n = 4 * 1024;//number of iterations (messages to be sent) consecutively
> int len = 8; //len of each message
>
> Process A (rank 0):
> for (i=0; i < n; i++){
> MPI_Send( sbuffer, len, MPI_BYTE,to,i,MPI_COMM_WORLD);
> }
> Process B (rank 1):
> for (i=0; i < n; i++){
> MPI_Recv(rbuffer,len,MPI_BYTE,recv_from , i,MPI_COMM_WORLD, &status);
> }
> (It's a benchmark program... will run with increasing messages sizes.. )
> (I tried with the same tag on all iterations - and got the same)
>
> It works fine for n (number of messages) equals to 3k (for example), but do
> not work with n equals to 4k (for messages of 8 bytes 4k iterations seems to
> be the treshould).
>
> The error messages (complete output attached):
> malloc debug: Request for 8396964 bytes failed (class/ompi_free_list.c, 142)
> mpptest: btl_tcp_endpoint.c:624: mca_btl_tcp_endpoint_recv_handler:
> Assertion `0
> == btl_endpoint->endpoint_cache_length' failed.
> Signal:6 info.si_errno:0(Success) si_code:-6()
>
>
> Considerations:
> It works for synchronous send (MPI_Ssend).
> It works with MPICH2 ( 1.0.3).
> It is a benchmark program, I want to flood the network to measure the
> bandwidth ... (for different message sizes)
>
>
> Thanks
>
> Marcelo
> _______________________________________________
> users mailing list
> users_at_[hidden]
> http://www.open-mpi.org/mailman/listinfo.cgi/users

-- 
Jeff Squyres
Server Virtualization Business Unit
Cisco Systems